HISTORY AND PATHOLOGY OF VACCINATION VOL. I. A CRITICAL INQUIRY ---EDGAR M. CROOKSHANK, M.B.

HISTORY AND PATHOLOGY OF

VACCINATION

A CRITICAL INQUIRY
BY
EDGAR M. CROOKSHANK, M.B.

PROFESSOR OF COMPARATIVE .PATHOLOGY AND BACTERIOLOGY IN, AND FELLOW OF,
KING'S COLLEGE, LONDON.

AUTHOR OF PAPERS ON THE ETIOLOGY OF SCARLET FEVER; ANTHRAX IN SWINE ;
TUBERCULOSIS AND THE PUBLIC MILK SUPPLY ; AND THE HISTORY AND
PATHOLOGY OF ACTINOMYCOSIS ; IN REPORTS OF THE AGRICULTURAL
DEPARTMENT OF THE PRIVY COUNCIL, ETC.

AUTHOR OF A MANUAL OF BACTERIOLOGY, ETC.

LONDON
H. K. LEWIS, 136, GOWER STREET, W.C.
1889

VOL. I.
PREFACE.
CON T E N T S OF VOL. I.
CHAPTER 1. HISTORY OF SMALL POX INOCULATION IN FOREIGN COUNTRIES
CHAPTER 2. HISTORY OF INOCULATION IN GREAT BRITAIN AND IRELAND
CHAPTER 3. THE OPERATION OF INOCULATION .....
CHAPTER 4. HAYGARTH'S SYSTEM FOR PREVENTING SMALL POX .
CHAPTER 5. THE TRADITIONS OF THE DAIRYMAIDS ...
CHAPTER 6. LIFE AND LETTERS OF EDWARD JENNER .
CHAPTER 7. JENNER'S REJECTED " INQUIRY "......
CHAPTER 8. JENNER'S PUBLISHED " INQUIRY " .
CHAPTER 9. HUMAN SMALL POX AS A SOURCE OF "VACCINE LYMPH"
CHAPTER 10. CATTLE PLAGUE AS A SOURCE OF "VACCINE LYMPH " .
CHAPTER 11. SHEEP SMALL POX AS A SOURCE OF "VACCINE LYMPH "
CHAPTER 12. GOAT POX AS A SOURCE OF ''VACCINE LYMPH "
CHAPTER 13. COW POX AS A SOURCE OF "VACCINE LYMPH "
Characters of the Disease in the Cow.
Casual Cow Pox on the Hands of Milkers.
Effects of Inoculation of Virulent Cow Pox Lymph.
Effects of Inoculation of Mitigated Cow Pox Lymph.
CHAPTER 14. "GREASE " AS A SOURCE OF " VACCINE LYMPH " .
First Outbreak at Toulouse.
Outbreak at Alfort.
Second Outbreak at Toulouse.
Horse Pox in Algeria.
CHAPTER 15. INTRODUCTION OF VACCINATION IN FOREIGN COUNTRIES ,
CHAPTER 16. PROGRESS OF VACCINATION IN ENGLAND

VOLUME 2

CONTENTS.
An Inquiry into the Causes and Effects of the Various VACCINAE.—EDWARD JENNER. See.

An Inquiry Concerning the History of the Cow Pox.—GEORGE PEARSON, M.D., F.R.S.

Reports of a Series of Inoculations for the Variolae Vaccinae, or Cow-Pox.—WILLIAM WOODVILLE, M.D., F.R.S.

Further Observations on the Various Vaccinae, or Cow Pox.—EDWARD JENNER, M.D., F.R.S., F.L.S., &c. . See

An Address to the Public on the Advantages of Vaccine Inoculation.—HENRY JENNER, Surgeon, F.L S., &c. .

A Conscious View of Circumstances and Proceedings RESPECTING VACCINE INOCULATION.—ANONYMOUS

A Continuation of Facts and Observations relative to the Variolae Vaccinae.—EDWARD JENNER, M.D., F.R.S,, &c See

The Origin of the Vaccine Inoculation.—EDWARD JENNER, M.D., F.R.S., &c. See

An Account of some Experiments on the Origin of the Cow-Pox.— JOHN G. LOY, M.D

An Examination of that Part of the Evidence relative to Cow-Pox, &c—W. R. ROGERS

A Letter occasioned by the Many Failures of Cow-Pox.—JOHN BIRCH, Esq
On Cow Pox discovered at Passy (near Paris)—M. BOUSQUET

Account of a Supply of Fresh Vaccine Virus from the Cow.—ESTLIN

Observations on the Variolae Vaccinae.—CEELY.

Report of the Vaccination Section of the Provincial Medical and Surgical Association

Further Observations on the Variolae Vaccinae.—CEELY

A Detail of Experiments confirming the Power of Cow pox to protect the constitution from a subsequent attack of Small Pox, by proving the Identity of the Two Diseases.—JOHN BADCOCK. . .

Correspondence from Members of the Medical Profession, RELATIVE TO RECENT SUPPLIES OF VARIOLAE VACCINAE, or Modified Small Pox

Small Pox and Cow Pox.—AUZIAS-TURENNE

Cow Pox at Eysines (Laforet) (First Outbreak), 1881.—DUBREUILH

Cow Pox at Eysines (Second Outbreak), 1883. And at Cerons, 1884.—LA YET

Outbreak of Cow Pox near Cricklade (Wiltshire), 1887.—CROOKSHANK

PREFACE.
IN this Preface I have thought it necessary to lay before the profession, the circumstances which have led to the production of these volumes.

I had devoted myself for some time to pathological researches in connection with the communicable diseases of man and the lower animals, when the discovery of an outbreak of Cow Pox, in 1887, led me to investigate the history and pathology of this affection. At that time I accepted and taught the doctrines, in reference to this disease, which are commonly held by the profession, and are described in the text-books of medicine.

In endeavouring to discover the origin of this outbreak, it was proved beyond question that the cows had not been infected by milkers suffering from Small Pox. This fact, together with the clinical characters of the disease in the cows, and in the milkers infected from the cows, and the certainty, that I had to deal "not with an infectious disease like cattle-plague or pleuro-pneumonia, but with a disease which is communicated solely by contact" convinced me that the commonly accepted descriptions of the nature and origin of Cow Pox were purely theoretical. As the natural Cow Pox had not been investigated in this country for nearly half a century, it was obvious that a much neglected field of comparative pathology had been opened up for further inquiry.

My interest in this subject was further stimulated by Sir James Paget, who very kindly examined one of the milkers casually infected from the cows, and while so doing drew my attention to a copy of Dr. Creighton's work on Cow Pox and Vaccinal Syphilis, then just published. The question naturally arose, whether my observations supported or refuted the conclusions arrived at by Dr. Creighton as the result of his historical researches.

While attending at the National Vaccine Establishment of the Local Government Board, I was unable to obtain any exact details, clinical or pathological, of the source of the lymph which was employed there. From my experience of this and other vaccination stations, I found that both official and unofficial vaccinators were completely occupied with the technique of vaccination, to the exclusion of any precise knowledge of the history and pathology of the diseases from which their lymph stocks had been obtained. Thus, at this early stage of my investigation, I felt that what Ceely said, in 1840, was still true: "The imperfect knowledge which we at present possess on many points connected with the natural history of the variolœ vaccinœ, and the numerous and formidable impediments to the improvement and extension of that knowledge, demand the continuance of vigilant, patient, and diligent inquiry."

In January, 1888; while I was studying the literature of the subject at the Library of the Royal College of Surgeons, Mr. Baily, the librarian, to whom I am indebted for much courteous assistance, was engaged in re-cataloguing the Library. He found a parcel of MSS., which he thought might prove of interest to me. It contained letters from Hunter to Jenner, and a manuscript which was thought to be the MS. of Jenner's Inquiry. On carefully perusing it, I discovered that it differed in many respects from the published Inquiry; it was, in fact, Jenner's Communication to the Royal Society. I was so struck by the contents of this paper, and the small amount of evidence upon which Jenner had first ventured to propose the substitution of Cow Pox inoculation or vaccination for the old system of Small Pox inoculation or variolation, that I was induced to carefully look into the life of Jenner and the early history of vaccination, as contained in Baron's Biography, and in the correspondence and articles on the subject in contemporary medical and scientific periodicals
Now that the value of Jenner's MS. and the interest attached thereto, have been pointed out, it has been carefully preserved, and entered in the catalogue of the Library, and may be consulted by any one desiring to do so. From a letter, dated 1877, which will be found in the parcel, it will be seen that Hunter's letters and Jenner's MS. were given to Sir James Paget, by a lady into whose possession they had passed on the death and by the will of her cousin, the late Colonel Jenner, son of Dr. Jenner. On June 4th, 1879, Sir James Paget wrote to Mr. [now Sir John] Simon, President of the College, presenting the MSS. to the Library of the College. The MSS. appear to have remained in a drawer until they were brought to light under the circumstances which I have just related.

I gradually became so deeply impressed with the small amount of knowledge possessed by practitioners, concerning Cow Pox and other sources of vaccine lymph, and with the conflicting teachings and opinions of leading authorities, in both the medical and veterinary professions, that I determined to investigate the subject for myself. From antiquarian booksellers in Paris, Berlin, and in this country, I succeeded in a very short time in obtaining a large number of works dealing with the early history of vaccination.

They at the same time forwarded many works on Small Pox inoculation, and thus my interest was aroused in this subject also, and its bearing upon the history and pathology of vaccination was soon apparent.

In February, 1888, I resolved to consult the leading authorities in France, and to obtain, if possible, the history both of the Bordeaux Lymph, and of the outbreaks of Cow Pox which had been met with in that country during the time that the disease was supposed to be extinct in this.

I take this opportunity of thanking M. Hervieux for much information, and for his kindness in affording me opportunities for observing the system of public vaccination in Paris.

To M. Cagny, I cannot sufficiently express my indebtedness both for introductions to his colleagues, and for presenting me with a copy of the work of Auzias - Turenne containing his classical essays on Cow Pox and Horse Pox.

From Paris, I proceeded to Bordeaux where Dr. Layet and M. Baillet received me with the greatest courtesy, and afforded me every opportunity of obtaining information concerning the Municipal Vaccination Service ; and we discussed the details of the recent outbreaks of Cow Pox which they had observed. I also succeeded in obtaining, through the kindness of Dr. Dubreuilh, a full account of the "spontaneous" outbreak which was the source of a recent official 1

1 Report of the Medical Officer of the Local Government Board. 1882. p. iv.
stock of vaccine lymph now employed in this country, though abandoned at the Animal Vaccine Station at Bordeaux.1 At Toulouse, at the Veterinary School, I was able to obtain further information about the nature, clinical characters, and origin of Cow Pox and Horse Pox. M. Peuch, the distinguished Professor of Veterinary Pathology, furnished me with the details of his remarkable investigations into Horse Pox, and has since granted me permission to reproduce the coloured plates illustrating this subject. M. Peuch's researches and observations will be of the greatest value in bringing to light a disease of the horse which is still unrecognised by practical veterinarians in this country.

I also had the opportunity of studying the clinical characters, and the results of inoculation of Sheep Pox.

At Montpellier, I visited the Vaccine Establishment of M. Pourquier, and obtained from him some interesting information. On returning to Paris, I was most kindly received by M. Chauveau, who discussed with me the affinities of Cow Pox, and showed me the beautiful and valuable drawings which had been prepared for the Report of the Lyons Commission, but unfortunately had been withheld from publication owing to the expense that would have been entailed.

1 British Medical Journal. July 14th, 1888.
On returning to England, I renewed my investigations in Gloucestershire, Wiltshire, and Dorsetshire. I obtained additional information with reference to cases of Cow Pox in this country, and fully realised that the belief that this disease is extinct in England has resulted from the determined and often successful attempts which are made by farmers (for obvious reasons) to conceal outbreaks when they occur. I also followed up the history of Mr. Jesty, by visiting Worth Matravers in the Isle of Purbeck, and obtaining all the local information possible.

Lastly, for reference to some works, copies of which I have not hitherto succeeded in obtaining, I have availed myself of the British Museum and our medical libraries.

The difficulty in gaining access to these works is no doubt the reason why the originals have been so little read. It would hardly be possible for the practitioner with but little time at his disposal, and, if in the country, without access to many medical libraries, to undertake such an inquiry; but I trust that the system which has been followed in this work of giving copious extracts will induce others to study the original authorities. All the selections from Jenner's correspondence have been drawn from Baron's Biography, with the exception of one letter, which was obtained for me by Mr. W. K. Dale.
I desire to thank him ; and also the owner for permission to reproduce it in fac-simile. The essays composing the second volume have been reprinted with the object of affording references in a handy form.

My best thanks are due to Mr. James Ceely for approving of the proposal to reprint his brother's classical papers, and to Mr. Badcock for granting me permission to reprint his pamphlet.

In conclusion, I desire to thank Messrs. W. K. Dale and E. F. Herroun for their assistance in passing the proof sheets through the press. Messrs. Vincent, Brooks, Day, & Son are to be congratulated upon the success with which they have reproduced the coloured plates.

> > > > > > > > > Edgar M. Crookshank.

Manchester Square W., April 1889
Small Pox, and the lower classes of people were so little afraid of it that social intercourse was maintained as usual. The nurses and common people called it the Swine or Pig Pox.

According to Adams, the pustules of this variety are never very, large, but round and uniform in proportion as the disease is well marked. As they increase, the upper surface extends over the base, and as they dry, the scab becomes nearly globular. The scab is of a pale amber colour, and dries much harder than in the common distinct disease. From the figure,
1 Adams. A Popular View of Vaccine Inoculation. 1807.
CHAPTER 9. HUMAN SMALL POX AS A SOURCE OF " VACCINE LYMPH '

Sydenham was the first to distinguish different varieties of Small Pox. Adams l experienced outbreaks of what the nurses called the white sort, which he believed to be the same as a variety mentioned by Sydenham, which left no marks. A similar outbreak which prevailed in Gloucestershire was referred to by Jenner. The attack was as mild as in the inoculated Small Pox, and the lower classes of people were so little afraid of it that social intercourse was maintained as usual. The nurses and common people called it the Swine or Pig Pox.

According to Adams, the pustules of this variety are never very, large, but round and uniform in proportion as the disease is well marked. As they increase, the upper surface extends over the base, and as they dry, the scab becomes nearly globular. The scab is of a pale amber colour, and dries much harder than in the common distinct disease. From the figure,

1 Adams. A Popular View of Vaccine Inoculation. 1807.
colour, and other properties preserved throughout the whole progress, Adams called this variety the pearl sort.

In the chapters on Small Pox inoculation, I have drawn attention not only to the various methods of inoculation, but also to the different results which followed the employment of virus of different strengths.

Inoculators had learnt by experience that it was not advisable to take matter from the confluent Small Pox, as a severe attack would probably follow ; and, therefore, in the directions given, it is constantly recommended that a mild sort of Small Pox should alone be used. In the hands of the Suttons, inoculation became still milder, because they were always careful to inoculate with variolous lymph; and as Sutton was said to have been more successful in his early practice, it is probable that the success largely depended upon the accidental circumstance of having first started his inoculations with matter from an outbreak of a very mild Small Pox, and the mild character of this variety was, for a time, successfully propagated from arm to arm. Adams1 obtained still more striking results, which I will relate in his own words.

1 Adams, loc. cit., p. 27.

> "By continuing with great caution to inoculate at the hospital from pearl Small Pox, and afterwards by selecting those arms which had the most appearance of Cow Pox, we at last succeeded in procuring a succession of arms so nearly resembling the vaccine, that an universal suspicion prevailed among the parents, that they were deceived by the substitution of one for the other. This will be readily understood by the following register :

> "Register I.

> "August 14th, 1805, William Croft was inoculated, with several others, from a subject who had casual Small Pox. Croft had diarrhoea three days after he was inoculated, a circumstance in children often favourable for the future disease.

> " On the 3rd day, the insertion appeared elevated.
> " 6th, a vesicle.
> " 8th, the vesicle spread.
> " 10th, has a vaccine appearance with fever.
> "13th, one hundred and fifty pustules appeared which passed regularly through their stages, somewhat shortened, as often happens in inoculation.

> " Rogers was inoculated 26th August, from Croft, in two places. Only one took effect, which was perfectly vaccine in all its stages. The child had been previously ill, so that it was difficult to ascertain whether any or what degree of constitutional disorder was produced by the inoculation.

> "Mary Ann Dobins, having been previously inoculated from Croft without effect, was,
> "September 2nd, inoculated from Rogers. The arm proved vaccine in all its stages.
> " On the same day, were inoculated from Rogers—

> " I. Richard Jude. His arm was vaccine in every stage.
> " On the 13th day, as the arm was drying, appeared one hundred and fifty variolous pustules.

> "II. Eleanor Watts. Arm vaccine.
> " Pustules appeared on the 11th day.
> "On the 13th, five hundred were counted; all maturated, but dried early.

> " III. Elizabeth Gray. Her arm regularly vaccine to the 8th day.

> "On the 10th, appeared stationary, in consequence of which inoculation was repeated from Edward Christian's arm, who had been inoculated twelve days.

> " 12th day, the arm first inoculated retains its vaccine appearance, though somewhat jagged with elevations round the vesicle. She had fever the day before, and pustules first appeared on the body.

> " 13th, the arm retains its circumscription, but is yellow. The fever considerable all night.

> " 14th, the first inoculation dry; the second contains a 3'ellow crystalline lymph with areola. Has upwards of sixty small circumscribed pustules.

> " 15th, arms drying, pustules suppurating. " 19th, pustules drying. " 22nd, scabbed.

> "IV. Thomas Dyson. His arm was perfectly vaccine in all its stages.

> " 10th day, a few pustules appeared ; had been sick on the 9th evening.

> " 12th day, the arm drying. " From Dobins, seven were inoculated ; of these " Five had no eruption ; the arms were vaccine in all the stages, and in the appearance of the scab.

> " One had a perfectly vaccine appearance on the arm, areola, and brown scab, with one hundred variolous pustules, which appeared on the 12th day, and began to dry on the 16th ; but the desiccation was not completed till the 29th, when the appearance was horny.

> "The other had a vaccine arm somewhat irregular, with fever, but no pustules.

> " From the last, were inoculated four.

> "Of these, two had vaccine arms, perfect in all their stages, and without pustules.

> " One had the vaccine vesicle regular, excepting that the edges sloped in such a manner, that the base was broader than the apex. The top was, however, flat, and the whole appearance such as occasionally occurs in the genuine vaccine.

> "The other had small pustules, which dried, as well as the place of insertion, by the 15 th.

> " Elizabeth Gray, we have observed, had pustules. Two were inoculated from her arm, and two from, her pustules.

> "The two from the arm had the legitimate vaccine appearance.. " One, from the pustules, had fever with general efflorescence.

> "The other had all the symptoms of vaccination, with the areola; but the contents of the vesicle became yellow before it dried.

> "It is unnecessary, in this place, to pursue this register any further. Suffice it to say that the enemies to vaccination, about this time, excited so great a clamour that every mother was suspicious lest her child should be clandestinely inoculated with the Cow Pox; and even those who saw matter taken from secondary pustules, and applied to the arm, were scarcely satisfied unless their own children had unequivocal symptoms of Small Pox. Reflecting, therefore, that an event of this kind must either occur again, or be unsatisfactory from being unsupported, we contented ourselves with the record preserved in the register, waiting till it should be explained by subsequent occurrences.

> " This is not the only time that we have been interrupted in our attempt to perpetuate a favourable Small Pox. For though it was urged to the parents, that before the discovery of Cow Pox, the inoculation of the Small Pox was sometimes only followed by a pustule at the arm, with the attendant fever; yet the suspicions of many were equal to their prejudices : nothing less than secondary pustules would satisfy them, and some even expressed their doubts, if the eruption was scanty or disappeared early."

It was not until many years afterwards, that Guillon1 also, found that a vesicle, with the physical characters of the vaccine vesicle, could be raised from Small Pox by cultivation.

1 The London Medical Repository and Review, p. 426. 1827.

Dr. Thiele, of Kasan, in 1839, succeeded in the following manner. Lymph from human Small Pox was allowed to remain, for ten days between slips of glass fastened together with wax. The virus was then diluted with warm cow's milk, and inoculated like ordinary vaccine lymph. Large vesicles resulted. There were febrile symptoms from the third to the fourth day, and a secondary onset of fever, much more pronounced, between the eleventh and the fourteenth days. The areola was strongly marked, and not confined to the inoculated place which was occasionally surrounded by minute secondary vesicles. The scar was larger and deeper than usual, and the edges occasionally sharply defined.

If watched through ten removes, the vesicles were found gradually to assume all the classical characters of the vaccine vesicle. As soon as the secondary fever ceased to occur, inoculation from arm to arm was practised without diluting the lymph with cow's milk.

This variety of vaccine lymph was, later, designated lacto-varioline. That a " vaccine vesicle " could be produced direct from human Small Pox, without, that is to say, the intervention of the cow, was regarded as an extraordinary and novel fact. But the results were precisely the same as those obtained by Adams and by Guillon, which, so far as I am aware, had been entirely overlooked. The production of a " vaccine vesicle" from a mixture of variolous lymph and milk was not vaccination in the strict meaning of that term, but simply variolation in an extremely mild form.

Precisely similar results were obtained by Gassner in 1801, who succeeded in reducing the effects of Small Pox virus to the production of "vaccine vesicles" on one out of eleven cows which had been inoculated.

The ordinary phenomena of vaccination were observed in four children inoculated from this cow, and similar results followed in seventeen children inoculated from them.

In 1828, Dr. McMichael reported to the Royal College of Physicians that several physicians in Egypt, had succeeded in raising " vaccine lymph " by inoculation of cows with Small Pox, and that children were successfully " vaccinated."

In 1830, Dr. Sonderland, of Barmen, claimed to have produced vaccine in cows by infection from human Small Pox. An account of these experiments was published in the Medical Repository, with the following introduction :—

> "The author of the paper which we shall here translate almost without abridgement, if his experiment be correct, has at length succeeded in establishing what physicians have long laboured to discover, a satisfactory and simple explanation of the protective power of Cow Pox against Small Pox, and, as announced, we will venture to say, the most important discovery which has been made in the pathology of these diseases since vaccination was first introduced, by showing that they are modifications of one another, and that Cow Pox in the cows is simply Small Pox in man, and may be produced in that animal at will by the variolous contagion. Of the authenticity of his facts we don't pretend to judge ; all we can say is that the author, if we judge from the language of Boufleu towards him, is a respectable practitioner, and a public medical officer."
> "'The simplest and surest mode of producing Cow Pox in the cow, and thus proving indisputably the identity between the contagion of Cow Pox and that of human Small Pox, is to follow the procedure here laid down. Take a woollen bedcover which has lain on the bed of a Small Pox patient who has died during the suppurating stage, or is suffering from the disease in a considerable degree, and is lying in a small imperfectly-ventilated apartment; and, when it is well penetrated by the contagion, roll it up immediately after death or the fourteenth day of the disease; wrap it in a linen cloth, and then spread for twenty-four hours on the back of a quey in such manner that it cannot be thrown off by the animal, then place it for twenty-four hours on the backs of each of three other queys, and afterwards hang in such manner in their stalls that its exhalation may rise upwards and be inhaled by them. In a few days the animal will fall sick and be seized with fever; and on the fourth or fifth day, the udders, and other parts covered with hard skin, will present an eruption of pustules which assume the well-known appearance of Cow Pox, and become filled with lymph. This lymph, which exactly resembles the lymph of genuine Cow Pox, if used for inoculating the human subject, will induce the vaccine or protective pock. The only precaution which it is necessary to observe is that the person about to be inoculated should not be exposed in any manner to the contagious effluvia of the cow-house, either directly or during the intervention of the experimentalist's clothes, otherwise he may have natural Small Pox. A bedcover, impregnated with the variolous contagion, if firmly rolled up and wrapped in linen, and afterwards in paper, and then properly packed in a bucket, will retain the contagion for at least two years, so as to infect the cow with Cow Pox, provided it can be kept in a cool shady place, where the temperature does not fall under thirty-two, or above fifty-two, degrees.

> "' My present occupations prevent me at this particular period from giving a full and scientific exposition of the consequences which must follow from this discovery, but I may state them shortly in the aphoristic form :—

> " ' I. This discovery is new; for, although many have suspected the identity of Small Pox in man and Cow Pox in the cow, and have in consequence performed inoculation with the matter of both, yet no one has previously ascertained the possibility of transmitting the contagion to the cow in the gaseous form so as to decide the question beyond all doubt.

> " ' 2. The desire of physicians and governments to discover Cow Pox in cows, in order to revive the vaccine lymph is more than fulfilled by the discovery of a simple method of engendering Cow Pox into the cow at will.

> " ' 3. Jenner's discovery of the protective power of vaccination hitherto imperfect, is now perfected, because the previously unknown nature and origin of Cow Pox are laid open.

> "'4. All previous uncertainty regarding the quality of vaccine matter, its degeneration, the loss of its protective property, and the like, must now cease, because we have obtained a clear insight into the nature of Cow Pox, and can lay down a substantial theory of its operation.

> "' 5. This discovery must tend to widen the boundaries of physiology, pathology, and therapeutics, since it shows how the subtle contagion of Small Pox was hostile to the nervous system of man ; may be conveyed in the aeriform state from him to the cow, and excite in that animal a similar disease; but in doing so, be changed by the special constitution of this class of animal into a permanent contagion of a different kind.

> " ' 6. An instructive lesson may be drawn from this discovery, how the poison of diseases in the gaseous form may be communicated to the lower animals, and according to the difference in their constitution, engender diversified products which may then be used as protective means against the diseases from which they originated. Such, for example, may be subsequently proved of scarlet fever, measles, yellow fever, and plague.

> "'7. It is now clear why, in recent times, Cow Pox has been seldom or never seen in the cow; for the Cow Pox of the cow arises merely from infection by the variolous exhalations from men recently affected with Small Pox and coming in contact with the cow. As epidemics of Small Pox have been rare daring the last thirty years, cows could seldom be exposed to infection, and have therefore seldom exhibited the disease.'"

Although attempts to confirm Dr. Sonderland's experiments failed in the hands of Ceely in England, and Macpherson and Lamb in India, and at Altort, Berlin, Weimar, Bergen, Dresden, Kasan, Utrecht, and Stockholm on the Continent; nevertheless, his aphorisms were accepted in support of the theory, the popular doctrine of the present day, that Cow Pox is Small Pox, modified by transmission through the cow. Had Dr. Sonderland and his followers been acquainted with the characters of the natural Cow Pox, and had they appreciated the fact that a vesicle with the physical characters of the vaccine vesicle, could be produced on the human subject, by management of variolous lymph without the intervention of the cow, they could hardly have come to such a conclusion. But this doctrine, owing to the explanation it afforded of the alleged protective power of Cow Pox against Small Pox, was a most seductive one. It was very widely accepted, and led to a complete misinterpretation of the successful variolation experiments which followed.

Dr. Thiele made a number of attempts to inoculate cows with variolous virus, and, at last, succeeded in producing a vesicle with the physical characters of the vaccine vesicle. From this he raised a stock of lymph, which at the time of his publication had passed through seventy-five generations, and had been used for the " vaccination" of over three thousand individuals. Thiele succeeded in confirming his first results. He insisted upon the necessity of selecting the animals. Cows from four to six years old, which had recently calved, and those with delicate pink skins, were preferred. The udder was shaved, and variolous lymph was alone employed, and the animals were exposed to a proper temperature (15° R.)

Before Dr. Thiele's experiments were published in this country, Mr. Ceely of Aylesbury, impressed with Dr. Sonderland's seventh aphorism, and influenced by the strong presumptive evidence of Baron that Small Pox had been common to men and brutes, determined to test the validity of Dr. Sonderland's experiments.

Attempts to infect cows by enveloping them with the sheets and blankets of Small Pox patients were without result. Ceely nevertheless persevered, and proceeded to try the effect of variolous inoculation.

In order to avoid all sources of error, Ceely himself took the Small Pox virus in the presence of his assistant, Mr. Taylor, on points that could never have been used before, as they were the teeth of a large comb cut for the purpose. Lymph was also collected in new capillary tubes. This lymph was inoculated on one side of the vulva of a heifer, and Cow Pox lymph on the other. One of the variolous punctures developed into an enormous vesicle, very unlike an ordinary vaccine vesicle. There can be no doubt that Ceely succeeded in raising a variolous vesicle. But it is very commonly supposed to have had a vaccinal origin, from the lancets having been mixed, or the vaccine transferred to the opposite side by the animal's tail.

The variolous character of this vesicle was fully borne out by the result of the accidental inoculation of his assistant.

> " My assistant, Mr. Taylor, to whom I had entrusted the lancet used in opening the variolous vesicle in the first experiment, on the tenth day, while I was engaged in the tedious process of charging points thereform, punctured the skin of his own hand, between the thumb and forefinger, with the instrument while moist with lymph, a circumstance with which at the time I was unacquainted. On the fourth day afterwards, he directed my attention to a hard, deep red, papular elevation on the spot, stating the cause, and at the same time assuring me that he had been vaccinated in infancy, and had subsequently had modified Small Pox. On the fifth day, there was a papulo-vesicular elevation, surrounded with a dark red areola, and much uneasiness in the part. In the evening, headache and other febrile symptoms appeared, with roseola and fiery red papulas on the face and other parts. On the sixth day, a more diffused and lighter areola surrounded the less abrupt elevation, which was now more perfectly vesicular; the constitutional symptoms increased, and the papulae, on the face, neck, trunk, and limbs, exhibited ash-coloured summits, and, through a lens, appeared to have slight central depressions. On the seventh day, it was manifest that the disease had reach its acme on the previous day. The areola was diminished, the vesicle was more apparent, some of the papulæ presented straw-coloured summits, and the roseola was declining, with an abatement of the febrile symptoms, a diminution of the tenderness of the axilla. On the eighth day, all these changes were more obvious, although he was not free from headache ; the papulae were more yellow and some were desiccating; the vesicles were larger but less active, and the areola was comparatively pale."

Chauveau, also, is of opinion that Mr. Taylor had an attack of Small Pox, and no doubt this is the true interpretation of what occurred. But Ceely's eyes were blinded by Sonderland's seventh aphorism. He looked upon this giant vesicle as the experimental confirmation of the doctrine that Cow Pox is modified Small Pox, and hence the opinion he expressed of Mr. Taylor's case, "this was evidently modified vaccine in a sanguine habit, with roseola and vesicular or vaccine lichen."

Points charged with lymph from the variolous vesicle were used on children. " Vaccine vesicles " were produced with the primary constitutional symptoms slight, and the secondary, proportioned to the extent and character of the areola. One child who suffered severely, had vomiting and delirium and extensive roseola, but no eruption was observed in any other case.

In December, 1840, Mr. Badcock,1 of Brighton, quite independently of Ceely, succeeded in variolating a cow. He was led to undertake the experiment from having suffered from a dangerous attack of Small Pox in 1836, which impressed his mind with the view " that the old vaccine had lost its protective influence by passing through so many constitutions."

1 Vol. ii., p. 513 et seq.

After making inquiries with a view to raising a fresh stock of vaccine from the cow, he came to the conclusion that the only satisfactory way would be to inoculate a cow with Small Pox matter. In the month of December 1840, he inoculated a fine young cow, on the teats and on the external labium, with Small Pox virus. No details of the operation have been recorded, but the result was successful. There was one well-developed vesicle on the external labium, and the lymph from it was employed by Badcock for "vaccinating " his son. The case excited considerable interest, and more than thirty members of the profession examined the boy. In four years, Badcock was able to repeat this experiment upon upwards of ninety cows, and, from occasional successful cases, to raise fresh supplies of "vaccine." According to the testimonials published by Badcock, there were slight differences observed, by several physicians, on comparing the vesicles with those produced by the current vaccine lymph. Badcock ultimately successfully variolated 37 out of 200 cows experimented upon. The vesicles were only perfect in 33, and these cases furnished lymph for 400 practitioners. In 1857, it was estimated that 14,000 people had been "vaccinated" with Badcock's lymph, and subsequently it was stated that Badcock himself had " vaccinated" upwards of 20,000 individuals.

It is quite a mistake to speak of this operation as vaccination. This method was simply a modification of the Suttonian system of Small Pox inoculation, in which, in the first remove, the cow was substituted for the human subject. I repeat, that all those who have been inoculated with Ceely's or Badcock's "variola-vaccine" lymph have not, in the true sense of the word, been vaccinated; they have not been Cow Poxed, but they have been variolated. This is amply verified by the results which have followed in the hands of others who have variolated cows, and used the products for "vaccination."

In 1836, Dr. Martin, of Attleborough, Mass., inoculated the cow's udder with variolous lymph, and by inoculating children from the variolated cow, produced an epidemic of Small Pox with fatal cases.

In 1839, Reiter, of Munich, after fifty unsuccessful attempts, succeeded in producing a vesicle with all the characters of the vaccine vesicle. The variolous lymph which had been employed in that case, when inoculated into another cow, gave rise to results similar to those obtained by Chauveau. A child inoculated from the successful vesicle, contracted Small Pox.

In 1847, variolation of the cow was successfully performed at Berlin, but the products inoculated in the human subject resulted in retro-variolisation, and one of the experimental children died of confluent Small Pox.

In 1864. the Lyons Commission encountered similar disasters. Chauveau, in his classical experiments, made in the name of the Lyons Commission, 1863 — 1865, inoculated seventeen animals with virulent variolous lymph (en pleine activité). He obtained very small papules, which became insignificant in the second remove. The contents of these papules inoculated into children always produced Small Pox, which recalled, in its course, the results obtained by the early inoculators of Small Pox. One of the children transmitted Small Pox to another child, who communicated it to the mother. Some of the children died. In 1871, Chauveau produced precisely similar results. He inoculated Small Pox and Cow Pox on the same animal. The Small Pox virus still produced Small Pox, and the Cow Pox virus produced Cow Pox. The two viruses mixed and inoculated in bovines engendered Cow Pox only ; and a similar result was obtained in children after six successive transmissions through the cow. Chauveau therefore believes in the autonomy of Cow Pox; in other words, in the impossibility of transforming Small Pox into Cow Pox.

More recently, Voit, at the vaccination station at Hamburg, succeeded in producing " variola-vaccine." He inoculated a calf with Small Pox lymph and Cow Pox lymph, on parts of the body far distant from each other. The variolous lymph had been collected on the fourth day. The Cow Pox took feebly ; the puncures, for the most part, were abortive, but those which developed, took the ordinary course. Of five inoculations with variolous lymph, four failed entirely, the fifth was transformed into a large, round, greyish vesicle, flattened, but not umbilicated. On the sixth day, it measured six millimetres. The areola was indistinct. It was excised on the sixth day, and the contents inoculated on the scrotum of a calf, three months old, and very fine vesicles, with the characters of vaccine vesicles, resulted. After successive cultivation on calves through twenty generations, the only difference in this virus from ordinary vaccine lymph was its slightly greater activity. But lymph taken from the second remove produced, in a child, marked fever after the sixth day, and acute eczema on the left knee ; on the ninth day, swollen glands in the axilla, and on the twelfth and sixteenth, eruptions (petites nodosites dissemines) which indicated its true variolous character.

The lymph from the third remove of calves, inoculated on four children, produced in three, serious complications, erysipelas, angina, and pneumonia. With lymph of the eighth remove, accidents continued to follow, but happily no deaths occurred. Voit was of opinion that the pustulous eruptions (pustules de variola-vaccine) which resulted on inoculation of the variolous virus in a cow, was true Small Pox of the cow, and that the nodular exanthem described by Chauveau was to be considered as an abortive form.
From the mere resemblance which existed between late removes of "variola-vaccine" and ordinary vaccine, Voit believed that he had succeeded in transforming Small Pox into Cow Pox. Voit was misled by appearances, in precisely the same way as Ceely, and others who have succeeded in reducing Small Pox to the appearances of a vaccine vesicle. The true variolous character of the "variola-vaccine" lymph, and the tendency, in less early removes, to produce Small Pox, is probably the reason why Voit has abandoned its use, in favour, as I am informed by M. Layet, of the ordinary spontaneous Cow Pox . lymph, from the vaccination station at Rotterdam.

The doctrine that Cow Pox is modified Small Pox was adhered to with extraordinary tenacity, and it became the official dogma that, as Small Pox protected against Small Pox, so Cow Pox, being modified Small Pox, must of necessity protect against Small Pox. Even distinguished pathologists and scientists were misled, and the doctrine was all the more acceptable in that it met a host of objections. It is interesting now to look back and see the reception meted out to Chauveau's opposite conclusions. Dr. Seaton, for example, in his Handbook of Vaccination, 1S65, thus speaks of M. Chauveau's experiments :—

> " With serosity taken from one of the cows and one of the horses, local vesicles, followed by general varioliform eruption, were in fact produced on three children, and from these children other variolous inoculations were performed. These results are regarded by the experimenters as showing that the inoculation of variola on horses and cows produces a true variolous infection, and that the organism of these animals is therefore incapable of transforming variola into vaccine. But they do not appear to me to lead at all necessarily to the conclusions thus drawn. The local effects produced by these inoculations were not in any respect greater than those produced by Ceely in cases which he regarded as failures, nor than the results which followed some variolous inoculations of horses (two) performed in 1863 by MM. Le Blanc and De Paul, which were regarded by them as unsuccessful. And it is not in the least improbable that if Mr. Ceely, or MM. Le Blanc and De Paul had, in the cases they describe, dealt with the tumid papules that arose as M. Chauveau and his colleagues did, they might have got from them the same stuff (sic) they had put in—stuff which had undergone no sort of transformation whatever, but which had lain where it was put as in a pouch, quite inert, giving rise only to local irritation, without inducing any sort of general affection or disease."

But Chauveau was perfectly correct. The eruption which follows inoculation of bovines with Small Pox, whether papular or vesicular, is still variolous. Ceely, Badcock, Chauveau, Voit, and others succeeded in ingrafting Small Pox on the cow, and when suitable lymph and suitable subjects were employed, a more or less benign vesicle resulted. And they ought to have known that similar results had been obtained on the human subject by Sutton and Dimsdale, and identical results by Adams, without transmission through the cow.

I, therefore, agree with Chauveau, with the exception of his statement that the persons so variolated must necessarily convey infection. This is only partly true ; it is not necessarily the case, as is amply borne out by the experience with Badcock's lymph. In this case, there has been no tendency for the inoculated to spread variola by infection, proving that a strain of benign variolous lymph can be cultivated by judicious selection, and completely deprived of any infectious properties.
CHAPTER 10.
CATTLE PLAGUE AS A SOURCE OF "VACCINE LYMPH."

Baron states in reference to the affinities alleged to exist between Cow Pox and Small Pox, that in no former instance did historical evidence and remarkable pathological phenomena so singularly and beneficially throw light on each other.

In this chapter, I propose to inquire into the historical evidence collected by Baron, and to ascertain whether his literary researches justified his opinion, and in what way they affected the practice of vaccination.

Jenner always considered that Small Pox and Cow Pox were modifications of the same distemper; and Baron, in an elaborate dissertation, not only endeavours to justify, but to fully establish, the doctrine of variolœ vaccinœ. I have already pointed out the train of thought which led Jenner to speak of Cow Pox as variolœ vaccinœ. From the similarity of the inoculated Cow Pox to the inoculated Small Pox, he concluded that these two diseases were derived from a source in common. He believed that " grease," by successive transmission through the human subject, became Small Pox, but, transmitted through the cow, it manifested itself in the form of Cow Pox. Cow Pox might, therefore, in this sense be regarded as Small Pox of the cow.

Baron took an entirely different ground for the establishment of this doctrine. He reasoned in this way. Eruptive diseases affecting man and the lower animals, had been known at different times, and in different countries. Just as there were numerous writers on Small Pox in man, so there were also many who had described an eruptive, pestilential disease existing among animals, especially cattle, to which they applied the name VARIOLA. The question then was whether the variolae of men and of the lower animals were essentially and originally the same.

In order to elucidate this question, Baron1 made an elaborate investigation into the history of this cattle disease. He quotes Lancisi, who asserted in his treatise, De Bovilla Peste, that this disease among horned cattle was epidemic in the Papal Territory in 1713 and 1714, and was similar to the outbreak which occurred in Italy nearly two centuries before, of which Frascatorius had given a description. In 1690, Ramazzini described this disease, and gave the following account of an outbreak in Italy in 1711:—

> 1 Baron, loc. cit.
> " The kind of affection which seemed to have declared exterminating war on the whole race of oxen, was evidently a malignant, destructive, and (if you will) a pestilential fever commencing with chills, rigor, horripilatio, succeeded quickly by pungent, violent heat diffused over the whole body, with frequency of pulse, and accompanied by great anxiety and heavy panting, together with stertor, and, in the commencement of the fever, with stupor and a kind of lethargy; a continual flow of stinking matter from the mouth and nostrils ; a most fœtid discharge from the bowels, and this at times bloody ; loss of appetite and rumination was altogether destroyed ; on the fifth, or sixth day, pustules broke out over the whole body of the animal, and tubercles resembling variola in kind and appearance; death common to all, and in the same manner, about the fifth or seventh day ; a very few escaped, and these rather by chance than the efficacy of any remedies."

Baron also quotes from the account published by Dr. Layard in the Philosophical Transactions for 1780.

> " The disease among horned cattle is an eruptive fever of the variolous kind: it bears all the characteristic symptoms, crisis and event of the Small Pox; and whether received by contagion, or by inoculation, has the same appearance, stages, and determination, except more favourable by inoculation, and with this distinctive and decisive property, that a beast once having had the sickness, naturally or artificially, never has it a second time.
> " According to the several prejudices of different countries, various opinions have arisen of the nature of this sickness. Such as are averse to inoculation, have obstinately refused to acknowledge it was similar to the Small Pox in the human body, and have very idly asserted, that the only intention of declaring this contagion to be a species of Small Pox, was purposely, and with no other view than to promote inoculation for the Small Pox. Others have as positively declared it to be a pestilential putrid fever, owing to a corrupted atmosphere, and arising from infected pastures. But unfortunately for the supporters of this opinion while the contagious distemper raged with the utmost violence on the coasts of Friesland, North and South Holland, Zealand, and Flanders there was not the least appearance of it on the English coast, from the North Foreland to the Humber, although the coast and climate are the same."

This destructive disease, so graphically described by Dr. Layard, appears to have been first noticed in England in the year 1745, and it was said to have been imported from Holland. I may continue Baron's argument in his own words.

> " When Dr. Layard wrote, it was of less importance than it is now, to illustrate the connection between the diseases of man and the inferior animals; no trials, therefore, were made to ascertain whether the variolœ of man could be communicated to the brute, or vice versa. The discovery of the Variolae Vaccinae has fully established the latter point; and although attempts to demonstrate the former have failed in the hands of some, other investigators have been more successful. ... It was quite unlooked for, and at first almost an incredible thing that a disorder immediately derived from one of our domestic animals should exert an influence so powerful and so beneficial on the human frame. But if it should appear that the disease incident to man and to beasts, had one common origin, and that an analogy, close and well-defined, may be traced in their subsequent history and progress, we shall have obtained evidence to explain pathological facts which are of the utmost value to mankind.
> " From what has been adduced, it is clear that a fatal, pestilential, eruptive disease, common to man and the inferior animals, has been known from the earliest period of authentic history; that the same, or at least a disease somewhat similar, continues to exist in various regions of the earth, often attended with great mortality. That it appears to have undergone various modifications in respect to virulence, and to be susceptible, by artificial communication, of still greater modifications.
> " Should it appear that the views which I have attempted to illustrate rest upon a solid foundation, they will tend, I would hope, to give a stability to the practice of vaccine inoculation which was not formerly experienced. They will also explain how sheep and horses or any other animals may be subject to the disease as well as cows or oxen; that it is not a poison peculiar only to one variety, but may be found and propagated among many. It will not, therefore, excite surprise, that matter capable of producing the genuine pustules should be found in the horse, as it unquestionably has been in this country and elsewhere; or that the disease should make its appearance among sheep, as it- is reported to do in Persia, and in goats in other countries. . . .
> "As the existence of the Variolae Vaccinae in the dairies of England would seem not to have been of very long duration, I think there is good ground for believing that the disease, as originally noticed by Dr. Jenner in Gloucestershire, was the endemic or local remains of the more general or epizootic disease which prevailed in many parts of the island at the period when Dr. Layard wrote."

Baron was Chairman of the Vaccination Committee of the British Association, and in its report these views are again brought forward, and there was no hesitation in speaking of Cow Pox as Cow Small Pox.

In order to make this account agree, to some extent, with Jenner's belief in the origin of Cow Pox from the horse's heel, Baron says that he regarded this doctrine as substantially true. He considered that it had been established by unquestionable evidence that matter from the horse produced a vesicle similar in appearance to the vaccine vesicle ; but, that this fact, though it proved in his opinion the identity of the diseases, did not establish the fact of their both originating in the horse.

> '' It seems certain that there are, at least, four animals—the horse, the cow, the sheep, and the goat—which are affected with a disorder communicable to man, and capable of securing him from a malignant form of the same disease."

The disease which Baron was describing was not Cow Pox but cattle-plague, and the totally erroneous views into which he had drifted, arose from that initial nosological error committed by Jenner, who branded Cow Pox as Variolœ Vaccinœ, or Small Pox of the Cow. That cattle-plague has a close affinity with human Small Pox is perfectly true, but it has no relation or connection whatever with Cow Pox. I shall give a brief history of the disease referred, to by Baron, and then I shall pass on to describe the disastrous results which followed the reception of the i>ariolcs vaccines- theory in India.

The outbreak of cattle-plague, described by Dr. Layard, commenced in England in 1745, and died out at the end of twelve years; it did not reappear until the summer of 1765. In 1769, the disease was again so prevalent and fatal as to be referred to by George III. in his speech at the opening of Parliament; in January 1770.

The resemblance of cattle-plague to human Small Pox had long; been recognised, and this view was endorsed in more recent times by Murchison,1 who regarded the analogy as very close. He pointed out that Small Pox is the only acute contagious disease

1 Report of the Commissioners appointed to inquire into the Origin and Nature, etc., of Cattle Plague, 1866, p. 74, et seq.
in man that assumes a pustular form. The eruption in rinderpest also, consists ,of pustules and scabs, while such differences as exist, may be explained by the differences in the skin of man and cattle, and are not greater than the differences which exist between varieties of human Small Pox. Murchison continues :—

> " In both, the eruption extends from the skin to the interior of the mouth and nostrils; in both, the pustules and the scabs are preceded or accompanied by patches of roseola; in both, they are occasionally interspersed with petechiæ; and in both, they sometimes leave behind pitted scars and discolorations on the cutis. . . . The other prominent symptoms of rinderpest are also those of Small Pox, viz., pyrexia, lumbar pain, salivation, and running from the nostrils; alvine flux, albuminuria, hæmaturia, and 'the typhoid state.' The anatomical lesions of the internal organs in rinderpest and unmodified Small Pox are identical, viz., congestion or inflammation of the mucous membranes of the air passages and digestive canal, patches of ecchymosis and even gangrene of the stomachs, and other mucous surfaces, and dark coloured blood. ... In both rinderpest and Small Pox, the duration of the pyrexial stage is on an average about eight days. In both diseases, a peculiarly offensive odour is exhaled from the body before and after death. The perspiration and other secretions of healthy cattle smell very differently from those of man, so that we can readily understand how the same disease may generate very different odours in the two animals. It may be mentioned that a medical correspondent in the country compared the smell of rinderpest to that of human variola weeks before he was aware of the intimate resemblance of the two maladies. . . . The two diseases resemble one another in their extreme contagiousness, and in the facility with which the poison is transmitted by fomites. Both diseases can be easily propagated by inoculation, and in both cases the inoculated disease is milder and less fatal than that resulting from infection. In both diseases, there is a period of incubation which is shorter when the poison has been introduced by inoculation than when it has been received by infection. Vaccinated persons are constantly exposed to Small Pox poison with impunity; and with regard to rinderpest, there are numerous instances in which individual cattle or entire herds have appeared to lead charmed lives in the midst of surrounding pestilence. This last fact has never been explained, but it would be readily accounted for on the supposition that rinderpest was the equivalent of Small Pox, and that the cattle who have enjoyed the immunity from it had previously suffered from ordinary Cow Pock."

Murchison admitted, that the theory that rinderpest was simply bovine Small Pox might be objected to, on the ground that there was no proof that it had communicated Small Pox to the human subject, and that, in fact, human Small Pox was far less prevalent in 1866, than it was a few years previously, when there was no rinderpest. Ceely, however, like Baron, maintained that cattle-plague was simply malignant Cow Pox ; and he did so principally from the fact that in the accidental transmission of rinderpest to the human subject, a vesicle was produced presenting the appearances, and running the ordinary course, of inoculated Cow Pox. The following is the case as reported by Ceely1 :—

1 Notes of the History of the Case of Mr. Henry Hancock, Veterinary Surgeon and Inspector, Uxbridge, drawn up by Robert Ceely, Esq. [Report of the Commissioners, loc cit, p. 79.]

> "On the 3rd December, 1865, Mr. Henry Hancock, veterinary inspector, Uxbridge, was engaged in superintending the autopsy of a bullock, recently dead of cattle plague. His assistant, who was performing the operation, while occupied in removing the skin from the scrotum, accidentally punctured the back of Mr. Hancock's hand with the point of the knife. The puncture being slight, was disregarded at the time, but was washed as soon as practicable, and thought of no more. On the 8th, five days afterwards, a small, slightly elevated, hard pimple was felt and seen on the site of the puncture. This gradually advanced till the 9th day of the puncture, the 4th from papulation, when the enlargement became distinctly vesicular. At that time there were but slight constitutional symptoms. On the next day, the 10th from the receipt of the puncture, the 5th from papulation, and the 2nd from vesiculation, he called upon his friend Mr. Rayner, of Uxbridge, who, on seeing the hand, inquired if the patient had been handling the udder of a cow, for that he could recognise a Cow Pock vesicle of the 9th day. The vesicle was then distended with limpid lymph, its margin elevated and rather brown, centre depressed and rather brown, and was surrounded with a large bright red areola. There was then considerable tumefaction extending from the knuckles above the wrist. The absorbent vessels were considerably inflamed. They, and the axillary glands, were tender and painful; the pulse, naturally slow, was accelerated ; there was much pain in the back and limbs, severe distracting headache, etc. ; all of which symptoms continued to increase during the two following days. At the end of that time the diffused areola had extended as far as the elbow. On the 18th December, fifteen days after the puncture, and ten days after papulation, the patient was seen in London by Drs. Klein and Murchison, and Professors Spooner and Simmonds. The local inflammation and the constitutional symptoms had partially subsided. The vesicle contained a rather turbid brownish fluid, and there were present all the indications of a declining vaccine vesicle. The above particulars were detailed to me by Mr. Hancock and Mr. Rayner on my visit to them at Uxbridge on the 20th December, and on my exhibiting the different phases of the vaccine vesicle on the hand of the milker (depicted in Plates III., IV., and V., in Further Observations on the Variolœ Vaccinœ, Transactions of the Provincial Medical and Surgical Association, vol. x.),1 Mr. Hancock immediately recognised there the exact correspondence with those which occurred on his hand. On this day, December 20th, being the 18th of the puncturation and the 13th of papulation, I observed manifest declining oedema on the back of the hand, as far as the elbow, with some patches here and there of declining redness near it. The vesicle, which had been many days poulticed, was depressed in the centre, puckered at its margin, but still raised on a palpabry firm basis. It certainly exhibited the appearances I have often seen at a corresponding stage of the loose vascular skin on the back of the hand of milkers affected with casual Cow Pox. A similar vesicle I have depicted (Plate V., fig. 2)2 in the work above referred to. The conclusion drawn from the appearance of the vesicle at this time was fortified by a consideration of the history of its development. The late appearance after the puncture, the tardy and gradual papulation and vesiculation, the period of the advent of the areola, its progress, extent and period of decline, all corresponding to those phenomena resulting from the casual inoculation of the milker by the cow affected with vaccinia. I could not; however, but regret that lymph was not abstracted at the proper time with a view to excluding all doubt as to its actual character."

1 Vide Plates XIII., XIV. 2 Plate XIV., fig. 1.

Murchison, in describing this case, gives practically the same account, with a few additional details. The appearances, as well as the entire history, were very different from the results of an ordinary poisoned wound, but coincided with those observed after vaccination. Murchison observed that Mr. Hancock had been vaccinated in infancy, and had one good vaccination mark upon his arm. In commenting further upon the case, Murchison pointed out that there was no evidence of cattle-plague, or Cow Small Pox, being transmitted by infection to man, but he attributed this to a difficulty in transferring the disease from one species to another, and he considered that it was, therefore, not surprising, on the supposition that rinderpest is a form of Small Pox, that human beings have not suffered from it; but he adds, it is not unreasonable to expect that inoculation of human beings with the virus of rinderpest, unprotected by vaccination, or by a previous attack of Small Pox, may, now and then, produce results similar to those obtained in India by Messrs. Macpherson, Brown, and Furnell, and those recently observed in this country in the case of Mr. Hancock, just as Small Pox in man is transmitted with great difficulty back to cows. Murchison concluded by pointing out that these remarks were adduced not to prove the identity of rinderpest and variola, or even that they were pathological equivalents, but to establish the very close analogy between the two diseases.

It was not unnatural that Murchison should have recommended vaccination as a prophylactic measure. In a supplementary report we read :—

> " Successful vaccination seemed to confer temporary immunity from the cattle plague, for in certain herds the vaccinated cattle, and they alone, escaped the disease. Further experience, however, has proved that this immunity, if real, is very transient. Cattle that have been successfully vaccinated, and in which the vaccination has run its course, when brought in contact with animals suffering from cattle plague, or when inoculated with the virus of cattle plague, have contracted the disease and died of it. The obvious inference is, that notwithstanding the close analogy between the cattle plague and human Small Pox, the former disease, like the so-called Small Pox of sheep, is uninfluenced by ordinary vaccinia, and, like it therefore, is in all probability a distinct species of disease from human Small Pox."

I will now pass on to describe the consequences in India, of Jenner and Baron's teaching that the terms Cow Pox and Cow Small Pox are interchangeable.

The cattle in Bengal were long subject to a malignant disease, which the natives designated by the same term as human variola—viz., Bussunt, Mhata or Gotee.

When the medical men in India heard that the source of vaccine lymph was a disease of cows with an eruption on the udder, called Cow Small Pox, it is not to be wondered at, that in order to raise a stock of lymph they resorted to a disease which had pustules on the udder, and was called Cow Small Pox by the natives of India.

In 1832, a series of inoculations was performed by Mr. Macpherson l in Bengal. I will give his account in extenso, from the report which he furnished as superintendent of vaccination at Moorshedabad.

> " Small Pox raged with the most destructive virulence in the city and vicinity during the months of May, June, July, and August last; and soon after receiving the Board's instructions, I made many attempts to introduce the disease in cows by exposing them to variolous contagion, covering them with the blankets of patients labouring under the disease, and by inoculation ; but all to no purpose, although, in these instances, the animals had very marked feverish symptoms, and in one those symptoms were followed by a few small ulcers on the abdomen, from which two cows were inoculated on the udder and teats; but no local or constitutional effects followed the operation or experiment.

> 1 Transactions of the Medical and Physical Society of Calcutta, p.169. 1883.

> " Finding I could not thus introduce variola I had two young cows inoculated with vaccine virus taken from the arm of a fine healthy child on the eighth day. Both cows had slight fever, and local inflammation on the third day. In one a vesicle formed on the fifth day, from which two children were inoculated, and in both instances the operation was followed by local and slight constitutional effects; but the pustules were elevated and opaque, they had no areola, and ran their course in five days, evidently spurious, consequently no attempt was made to carry this experiment farther. On inquiry among the natives, I learned that the cows in Bengal are subject to a disease which usually makes its appearance about the latter end of August or early in September, to which the same names are given as to variola in the human subject—viz., Bussunt, Mhata or Gotee, and on the 24th August, I was informed that several cows belonging to a native of Moidapore were affected. I consequently determined on again attempting to regenerate the vaccine virus from the original source. The animals which were first affected, amounting in one shed to eighteen or twenty, had been, for a day or two previously, dull and stupid ; they were always seized with distressing cough, and much phlegm collected in the mouth and fauces. The animals had apparently at this time no inclination for food, or, at all events, they were unable to satisfy their hunger. Their sufferings seemed to be greatest on the fifth and sixth days, when there was considerable fever, and pustules made their appearance all over the body, especially on the abdomen, which terminated in ulceration, the hair falling off wherever a pustule had run its course. The mouth and fauces appeared to be the principal seat of the disease, being in some instances one mass of ulceration, which in all probability extended to the stomach and alimentary canal.
> "In those cases where the mouth was very much affected the animals died apparently from inanition; whereas those cases in which the power of mastication, or even of swallowing, was retained, recovered much more rapidly than might have been expected from the previous severe sufferings and reduced state of the animals. The mortality may be calculated at from 15 to 20 per cent. From the above description of the disease, the Board will immediately observe that it assumes a much more serious complexion in this country than we have been taught to believe it does at home. I say taught, because I presume it has fallen to the lot of few to witness the disease in England; and it must be inferred from Dr. Jenner's and other medical writings on the subject that the animal not only continued to secrete milk, but that the milk was used; while in this country the little that is secreted is never made use of, and perhaps owing to this very circumstance the Guallahs or milkers in India are not affected with Cow Pox, as is the case with this description of persons in Gloucestershire and other counties in England where the disease is most prevalent. It is an extraordinary fact, and worthy of remark, that while the cows were thus affected no case of variola amongst the natives in the village presented itself, and although the people were ordinarily averse from handling or going much amongst the cattle at the time of disease, still they all scouted the idea of infection, stating they never heard of any one contracting disease from the cow, consequently they were under no alarm on that score. In consequence of the extreme jealousy with which all my inquiries on this subject were watched by the Hindoos, coupled with my own anxiety to conceal the object in view, I should have found very great difficulty in prosecuting my investigations had not the disease assumed the character of an epidemic, all the cattle in the neighbourhood becoming affected, and amongst others two belonging to one of my own vaccinators. I had them covered with blankets, leaving merely the udder and teats exposed to the air. On the seventh day two small pustules made their appearance on the teats of one, which dried up on the tenth, and the crusts were removed on the twelfth day; from those crusts eleven native children were inoculated. No effects whatsoever were produced or six of this number. Two had very slight inflammation on the arms on the third and fifth days; two had considerable local inflammation and slight heat of surface on the fifth, sixth, and seventh days, but no vesicle formed, although there was marked induration round the puncture. The remaining child's arm was slightly inflamed on the fourth morning, and a vesicle was apparent the next day, which continued to increase till the ninth day, when I was much gratified to find that it assumed all the characteristics of true vaccine. The poor little child, the subject of this experiment, was about five months old, and suffered much from fever for four days, by which he was greatly reduced, but very soon recovered.
> " Two children were vaccinated from this patient with the most complete success, but the symptomatic fever was more severe than I have ever observed it in former instances. Five children were vaccinated from those just mentioned, and the result was equally successful, after which no difficulty was experienced in disseminating the disease. With the view, however, of satisfying myself that true Cow Pox was introduced, I had two children who had been vaccinated with the fresh virus inoculated with Small Pox, and both were happily found to be secure. Another instance of the preservative powers of the new lymph deserves mention. Five children in the Gorah Bazaar at Berampore were vaccinated, and shortly afterwards were accidentally exposed to the variolous contagion by residing in the same huts where the disease was raging very dreadfully, but not one of those vaccinated was in the slightest degree affected by variola. Many children belonging to His Majesty's 49th Regiment and others in the families of residents, both civil and military, at this station and its vicinity, had been vaccinated with the regenerated virus. My friend Dr. French, who invariably has recourse to Bryce's test; Mr. Skipton, the superintendent surgeon, and several other medical men, have expressed themselves completely satisfied with the result. It is a gratifying fact that since the introduction of the new lymph the symptomatic fever has been more marked, and the natives have much greater confidence in the efficacy of the operation; in proof of which I need merely mention that the number presented for vaccination within the last three months has much exceeded that of any similar period for the previous two years. Variola has been more or less prevalent in this neighbourhood for the last seven months, and is now committing dreadful ravages in several parts of the city. Many instances are daily presenting themselves of the disease attacking those who have been previously affected, either naturally or by inoculation, and I am credibly informed that several of the latter have fallen victims to this dreadful scourge. It is melancholy to reflect that a city of ignorant and mercenary beings, such as the Tikadars in this country, are permitted annually to regenerate the disease, and thereby keep up a continual source of contagion, by which thousands of lives are sacrificed. Accompanying I have the pleasure to send some vaccine crusts, and ivory points armed with virus taken two days since, from .which, I entertain no doubt, the disease will be readily introduced in Calcutta, and should more be required it shall be immediately supplied."

According to Dr. Duncan Stewart1 this lymph was distributed throughout India.

Mr. Macpherson's example was followed by Mr. Furnell,2 in Assam, in 1834. He wrote as follows :—

> " Being very anxious to obtain a constant supply of vaccine virus, that which I got from Decca at various times having been followed by eruptions all over the body, and often with much fever, I was much interested by the account in the Transactions of the Medical Society detailing Mr. Macpherson's success in procuring vaccine lymph from the original source, the cow. I, therefore, in September last endeavoured to procure it in the same way, and having heard that several cows in the neighbourhood of Silhet were affected with the disease called Mhata or Gotee, I succeeded in getting one that was recovering, but it had a number of dried scabs over its body ; from those

> 1 Duncan Stewart. Report on Small Pox in Calcutta, p. 146.
> 2 Transactions of the Medical and Physical Society of Calcutta, p. 453-
> scabs I vaccinated four children without effect. My health being very bad at the time I was recommended to try Chirra for change of air, and left Silhet, requesting Mr. Brown, who kindly undertook my duty, to follow up the trial, at the same time offering a reward to any person who would bring a cow having the disease. Ere I returned to Silhet, Mr. Brown vaccinated several children, the first four, direct from the cow, and afterwards continued vaccinating from these children in succession. In the first four, the vaccine vesicle appeared most favourable on the eighth day, and in those who were vaccinated from them, the disease also appeared well marked on the eighth day. On my return, I found all in a fair train, as I thought, and continued vaccinating until the middle of November, when I was again obliged to go to Chirra for the benefit of my health. During my absence, Mr. Brown vaccinated Major Orchard's child on the 23rd of that month.
> "On my return on the 30th, I found that the vesicle did not appear in so forward a state as it should have been, but from its appearance, I thought that it had only been retarded in its progress, as at the time the babe was vaccinated she had a slight teething rash. On the 1st December, it looked much better, and on the evening of that day, the eighth of the vaccination, she had slight fever, and got in the evening a grain of calomel, and in the morning following, some castor oil, which affected her bowels slightly. On the evening of the second, the dose of calomel was repeated, and followed by oil next morning; the fever continued but slight. On the 3rd day, from the commencement of the fever, an eruption similar to that preceding Small Pox appeared, and in four days from that, she was completely covered with an eruption resembling the Small Pox at its confluent point, which ran through the same course as natural Small Pox. She was quite well on the 18th December, with a few pocky scabs scaling off. Before the above-mentioned eruption made its appearance three native children that were vaccinated on the same day as Mrs. Orchard's child, and from the same source, were brought to me, and the vesicles having a most favourable appearance, I vaccinated my own baby from one of them.
> "On the 1st December, being much alarmed on seeing the eruption on Mrs. Orchard's little girl, I sent for the boy from whom she was vaccinated, and found that he had had very little fever, but he had a few scabs, about twenty on his entire body. I also had the three children, who were brought to me on the day my little one was vaccinated, with me daily ; none of them had fever for more than one day ; in two of them a slight eruption, and on the third child there was not an eruption of any kind, and the vaccine vesicle in all of them went through its regular course. Notwitstanding this I took every precaution, and on the eighth day of vaccination, slight fever having come on, my little one had a little calomel and on the following morning some oil; yet the fever increased, and the dose was repeated on the following evening and the oil next morning with the desired effect. On the third day of the fever, a very thick eruption appeared on the face, and followed the course of Small Pox in its worst form. On the seventh day, from the commencement of the eruption her mouth and throat became so sore that she was unable to take the breast or any other food: it was very necessary to try to support her by a nourishing injection, notwithstanding which she sank on the 20th. The above report, it is hardly necessary to say, is given with great pain ; but I feel that it is right to do it, and to warn my brethren of the danger that sometimes occurs after taking the virus from the cow in this climate. Mhata in the cow of this country is decidedly a much more serious disease than the vaccine diseases in the animal in Europe. And it will be seen from the above statement that the inoculation from it is, in the human subject, followed by a most dreadful disease, but I will refrain from further remarks ; but I think it is necessary to state that such precautions were taken in this trial that it was almost impossible that any admixture of the variolous disease could have been made, as all the children mentioned were vaccinated direct from the cow.1 Two native vaccinators were deputed to vaccinate at the houses of the natives, and the third, in whom I had great

> 1 " The first four from the cow ; in the remainder the lymph was propagated from the first four children by Mr. Brown or myself."
> confidence, was employed about the station, and brought weekly-three or four healthy subjects to be vaccinated from those vaccinated by myself or Mr. Brown. Neither should we have known that the vaccination had been followed by any serious result had it not been for the above melancholy case, as, on the strictest inquiry, I cannot learn that any of the native children vaccinated, suffered from illness, not one having got any medicine; not the slightest pitting followed in either, as the eruption left no pits on Major Orchard's child. I have been so ill since the 22nd of last month that I have been obliged to leave Silhet, or I should have given this report earlier. I have within a few days learned that Captain Fisher's suffered also from a severe eruptive fever after vaccination from virus sent from Silhet.
> " In answer to your question I mentioned yesterday that I had heard from Silhet that young Mr. Tereneau was suffering under an affection of the kind.
> " I give you the words of my correspondent. ' n my letter yesterday I mentioned that young Tereneau had an eruption which I took for one of the patches of roseola. To-day, however, it has singularly enough been assuming the identical appearance which came out on your baby.' He was twice vaccinated, first in India, and afterwards in Scotland, and all right. I can only suppose that he caught the infection from Mrs. Fisher's child. I heard of several cases of Small Pox in Silhet about the time my little one was vaccinated. The native vaccinator, designated the third in the report, was taken ill about the 24th of December. His case was mentioned as a case of Small Pox; however, if it was, it was a very slight eruption. He did not keep his bed after it appeared. He was inoculated when a child."

According to Dr. Duncan Stewart, Mr. Brown made use of the scabs taken from the back or abdomen of the diseased cattle. These were reduced to a pulp with water, and employed for inoculating the four children mentioned above.

> "' In all four, vesicles in every respect resembling in their progress and when mature genuine vaccinia, made their appearance, and went the same regular course, the constitutional disturbance on the eighth day only being more severe than I have usually seen it in the latter.1'"
> " From these many other native children were inoculated, and no doubts of the genuineness of the lymph were excited until two English children were punctured from one of them, and it was then found that Small Pox supervened in both of these cases, and this was more than suspected to have happened in many of the native children, who had generally dispersed a few days after the operation, and were not afterwards heard of. One of the English children unhappily died."2

> 1 Quarterly Journal, Calcutta Medical Society, April 1837
> 2 Report on Small Pox in Calcutta, p. 148, by Duncan Stewart, M.D. 1844.

According to Baron, in 1837, another series of inoculations was performed by Mr. Macpherson in Bengal with virus from diseased cows, "on which occasion an eruptive complaint of the true variolous nature was produced;" and similar phenomena were observed at Gowalpara by Mr. Wood in 1838.

> " In several of his cases the symptoms were so severe as to excite apprehension that the disease would terminate fatally. He was so strongly impressed with this fact, that he thought it would be better to take human Small Pox rather than Cow Small Pox for inoculation, when the latter assumes its dangerous and fatal form."

From all these independent observations, if we accept them as correct, there would seem to be no doubt that cattle-plague virus inoculated in the human subject will produce a vesicle with the physical characters of the vaccine vesicle, and succeeded occasionally by an eruption which appears to have the characters of the eruption of cattle-plague. That cattle-plague is not infectious to man in the ordinary sense affords no proof that the disease may not be cultivated in the human subject by inoculation.

But these occurrences had to be explained away, for such circumstances were incompatible with the Small Pox theory of Cow Pox. We have only to turn again to Dr. Seaton's Handbook of Vaccination to find that ingenious explanations were forthcoming.

First of all, with regard to Dr. Macpherson's cases, Seaton admitted that the "vaccinations" were genuine, and that a stock of "vaccine" was established and was afterwards regularly continued. But he adds :—

> "From these facts it is not to be doubted that a case of Cow Pox in the cow had been met with; but what is to be doubted is that the Gotee—the malignant disease above referred to—was the source of this infection."

It was evidently impossible for Seaton to admit that, a vaccine vesicle could be produced by "management " of cattle-plague. But having admitted that a vaccine vesicle had somehow resulted, the only way out of the difficulty was to suppose that in some extraordinary way a case of Cow Pox had cropped up amidst the epidemic of cattle-plague. Nor does the fact that these experiments were repeated by Furnell in another part of India, appear in the least to have shaken his opinion. But while Seaton throws doubt upon the Gotee as the source of the lymph, he admits that the cows had " a generalised eruption of some kind or another," and he explains the pustular eruption in the. inoculated children as the result of an accidental admixture of either inoculated or casual human Small Pox. If we are to accept Seaton's view, we must, in some similar fashion, explain away the independent experience of Mr. Wood, of Gowalpara, and reject Ceely's and Murchison's accounts of inoculated cattle-plague on the hand of Mr. Hancock.
CHAPTER 11.
SHEEP SMALL POX AS A SOURCE OF "VACCINE LYMPH."

Sheep Pox, or variola ovina, is a common disease in some parts of Europe. In France, the disease is called la clavelee, and in Italy, vaccuolo. It has been introduced on several occasions into this country, but has been effectually stamped out. As in human Small Pox, there are varieties; the benign and the malignant; the discrete and the confluent. It is an acute febrile disease accompanied by a general vesiculo-pustular eruption, highly infectious, and capable of being propagated by inoculation or clavelisation.

It is very closely analogous to human Small Pox, and as another result of the misleading theory of Cow Pox being Cow Small Pox, not only was vaccination employed to protect sheep from Sheep Pox, but "vaccine lymph" was raised from Sheep Pox to protect human beings from Small Pox. These experiments were first performed in Italy, and have been described in detail by Sacco.1

1 Sacco. Trattato di Vaccinazione. p. 144. 1809.

> "In 1802, Dr. Marchelli communicated to the Societa di Emulazione of Genoa, to which I have also the honour to belong, the fact, that Small Pox of sheep might be substituted for Cow Pox; but as he had then made only a very few experiments with a view of ascertaining if it were efficacious or harmful when transmitted to man, he undertook to continue his researches, and then to publish the results. However, as he has recently informed me, he has not been able to do so in consequence of a long and severe illness from which he has been suffering; it is this which has retarded the publication of these valuable observations which would have led to important results, and would have thrown light on this branch of science.
> " Since I published my practical observations, I have, suggested the vaccination of sheep in order to protect them from the malady to which they are subject. I had indeed vaccinated more than seventy; but never having had the opportunity of seeing the Small Pox of these animals in our midst, I have not been able, for many years past, to ascertain whether by means of this inoculation they have been really protected. During the many journeys which I made with a view to extending vaccination in the kingdom, I redoubled my efforts in vain; I only succeeded in meeting with it in the State of Naples, at Capua. Passing through it in 1804, I saw a peasant who was driving a flock of seven sheep to the butcher's ; as I was obliged to stop in this town, I endeavoured to profit by the opportunity and to gain information on the subject.
> " Having noticed the miserable and dejected appearance of these sheep I stopped; and after putting various questions to the peasant, and examining the nature and character of the eruption and of the symptoms which accompanied it, I felt sure that the malady was the true Small Pox of sheep. The peasant told me that the malady was common in the neighbourhood, that fifty-four sheep had already been slaughtered, and that they would continue this method if the malady should develop in others, because treatment, besides being costly and difficult, was often useless, and exposed the rest of the flock to the contagion of the illness. I, with great care, collected matter from the finest vesicles, in small tubes, with the intention of testing it at the first opportunity.
> " On returning to my own province on Christmas Day of the same year, I went as soon as I had reached La Cattolica, which was then the last place on the frontier of the kingdom of Italy, in search of Dr. Legni. I informed him of my design, and my desire to make experiments with the matter obtained from the sheep, at Capua; he kindly seconded my project. He procured me six children, who were all inoculated with the matter, which was still fluid; I also inoculated two other infants with true vaccine, in order to institute a comparison. I then left the neighbourhood, entrusting the examination of the inoculated children to the above-named physician, who was to inform me of the results. A month later he sent me an exact account of all he had observed, the substance of which was, that the inoculations advanced at the different stages in the way which is usual with the vesicles of Cow Pox, and that he had failed to see any appreciable difference. He continued to vaccinate with the same matter for several years, and always with the same success.1
> 1 Extract from the letter of Dr. Mauro Legni, of June 29th, 1808 :— " Having pointed out its characters, I will now endeavour to sum up all that I have already written on the Small Pox of sheep; it has substantially a course in every way analogous to Cow Pox ; although the vesicles produced by the first insertions of the original matter appear to have had but little vigour; they were otherwise well formed. I have used this matter for two years, and I have inoculated more than three hundred infants with it, of whom one hundred were at Pesaro, where Small Pox has since reigned for three consecutive years ; and where, in spite of such a prolonged and fatal epidemic, all those inoculated with the sheep virus have been preserved from this fatal distemper, although they were in very close communication with those who were attacked by Small Pox."
> " I had no sooner arrived at Milan than I put to the test the remains of the matter which I had brought with me. I at once inoculated four infants with it, but was greatly surprised to find that it produced no effect upon them ; for want of fresh virus from the sheep I was then obliged to suspend further experiments.
> "In the month of October, 1806, I visited the Apennines with the object of helping the different districts by rendering the practice of vaccination general, and I then found means of verifying my theory. In many places I had the opportunity of observing this epidemic disease of sheep and of following it in all its stages.
> " I recommenced my researches in the neighbourhood of Montemiscoso, by inoculating the same malady in other sheep, and I ascertained that its course was only a little milder and more rapid, and that it acted precisely in the same way as inoculated Small Pox does in man. But, as this inoculation, although producing a milder disease, was still accompanied by the inconvenience of spreading the contagion and further diffusing it in the flock, I determined to vaccinate several sheep, with the object also of trying upon them the subsequent effects of Sheep Pox. The vaccination ran its proper course, and the experiment was successful, for the Sheep Pox no longer appeared, although the sheep associated with others which were infected. I had, therefore, assured myself by this experiment, that vaccination had rendered these sheep insusceptible of a similar malady.
> "As the ovine virus, inoculated in sheep, gave rise to a disease with symptoms which were regular, constant, and benign, I was induced to inoculate three infants with virus taken from a lamb which did not appear to be very ill : two others were inoculated in one arm with the ovine virus, and in the other with vaccine. I had on this occasion the satisfaction of seeing that all that Dr. Legni had written to me, from La Cattolica some years before, of the results of the inoculation which I had made with Sheep Pox, whilst passing through that place, was fully confirmed. Of the first three children inoculated with the sheep virus, two had one vesicle each; of the second children, one had only one vesicle on each arm, and the other had two, but only of the Cow Pox. The vesicles which had developed were so similar, that if I had not made a mark to remind myself on which arms I had inoculated the Cow Pox, and on which the Sheep Pox, I could not have distinguished one from the other. A few days after desiccation I inoculated with human Small Pox, the two children in whom the virus of the sheep had been completely successful, but no effects, either general or local, resulted.
> "Continuing my journey by Fosdinovo and Aulla, I had the opportunity of seeing the same sheep disease in various places, and of continuing my observations.
> " I inoculated several persons at Fosdinovo, amongst others the sons of Cancelliere Uccelli; others were made in Barbarasco near Aulla, where I also inoculated a cow with the same matter. I observed the course of those made at Fosdinovo, and in all, the ordinary vesicle was similar to that of Cow Pox. I left the Barbarasco cases to be observed by Dr. Magnani, an accomplished surgeon at Aulla, who sent me, eventually, an exact account of them.1

> " Proceeding to Lucca, I used the same virus to inoculate various people, and continued to vaccinate also in other places, always renewing the matter which had been originally taken from Sheep Pox, its course being always very regular, and its effect constant, as if it had been derived from a genuine Cow Pox."

> 1 Account sent by Doctor Antonio Magnani of Aulla, to Professor Luigi Sacco, Director-General of Vaccination, at the request of the latter conveyed in a memorandum of December 9th, 1806 :—
> " 1. On 8th and 11th of the month, I went to Barbarasco to see the four children whom you had inoculated with virus from the sheep, and designated in your list as Nos. 13, 14, 15, and 16, I saw only two of them, who had contracted the malady, namely, the brothers Gioacchino and Domenico Biondi; the former had two very beautiful vesicles on each arm, and the latter had only a single one on the right arm. After a very careful examination, I found that the vesicles on both boys were like those of true Cow Pox, surrounded by a red circle ; I further observed that the matter in both cases was different to that of true Cow Pox, that is to say that on the eighth day it was of a yellowish colour; and on this same day I noticed, moreover, that the vesicles already began to form a crust, and this was of a colour which tended to yellow.
> "2. On my first visit to these boys I took the virus from their vesicles, and found it to be serous, of a yellowish colour, and not at all limpid. With this matter I inoculated two other persons ; in both cases two vesicles on each arm appeared on the seventh day, filled with limpid matter, and I afterwards observed that these vesicles ran their course in the same manner as those of vaccinated persons.
> "3. However, the matter from these vesicles having been taken on the seventh day, I wished to inoculate three more persons in the commune of Tendola ; I found on visiting them on the eighth day, that they all had two vesicles on each arm; and I remarked besides that the humour which they contained was limpid and crystalline.
> "4. On inspection of the cow which you inoculated at several points with the same matter, I found on the udder a single vesicle, from which I took matter, which was yellowish in colour and not limpid, and used it to inoculate two other boys ; the first had two vesicles on each arm, and on the second I found only one, on the left arm ; in other respects the virus contained in the two vesicles was exactly similar to that of true Cow Pox. I have vaccinated with this matter other persons, and from these again I inoculated others, whom I visited soon alter, hoping that they would succeed equally well; the result was, and still is, most successful.
> "Aulla, January 29th, 1807."

In more recent times, extensive experiments were carried out in England to test the protective power of vaccination against Sheep Pox. According to Marson and Simmonds, it was very difficult to get Cow Pox to take on sheep, and when an effect was produced, the resulting affection, even when developed to its fullest extent, was very unlike the same disease in the human subject. In the sheep, it seldom produced anything more than a small papule, which occasionally resulted in the formation of a minute vesicle, or more commonly, a pustule, which was sometimes, although very rarely, surrounded by a slight areola. Generally, however, neither vesication nor pustulation followed; but a small scab was produced, which soon fell from the site of the puncture, leaving no trace behind. The disease passed quickly, and irregularly through its several stages, and terminated by the eighth or ninth day, and not unfrequently even before that time. Lymph was but rarely obtainable, and then only in the smallest quantity, and this on the fifth or sixth day succeeding the vaccination. The effects were only local, and the animal's health was not impaired.

Sheep were found to be just as susceptible of the Cow Pox virus on subsequent repetition of the inoculation as they were in the first instance, and hence the conclusion that Cow Pox was utterly worthless as a protective against Sheep Pox.

According to Depaul, however, Cow Pox takes characteristically on sheep, and Sheep Pox lymph inoculated on cows produces a perfect "vaccine." It is impossible to say whether these conflicting results depended upon the employment in the experiments of different breeds of sheep, or different stocks of vaccine lymph.

But the experiments of Marson and Simmonds, which have just been referred to, were not the only ones made in this country. Marson succeeded in raising on the human subject, a vesicle with the physical characters of the vaccine vesicle, and thus confirmed Sacco's "vaccinations."

> " When Small Pox appeared in this country in the sheep in 1847, we tried to communicate it, by inoculation, to the human subject, and thought we had succeeded in doing so, and the virus was carried on from one to another for several weeks in succession. The pock produced was very like Cow Pox, having only, as we thought, a bluer tinge, and was protective against Small Pox, as we ascertained by inoculating the patient afterwards with the lymph of human variola; but we had unfortunately used for the original ovination the same lancet instead of having a new one, as we ought to have had, that we had previously used for vaccinating; and although it was, as we believe, perfectly clean and free from vaccine lymph, nevertheless, as the disease could not be produced again in the human subject, either by Mr. Ceely of Aylesbury, who made repeated trials with .the lymph of Sheep Pox, or by ourselves, the experiment was never brought before the profession."

The failures in subsequent attempts do not invalidate the successful experiment, just as the numerous failures to raise a " vaccine vesicle " by variolation of cows, in no way disprove the results of more fortunate experimenters. In both cases, the effects depend upon the nature and " management " of the lymph.
CHAPTER 12.
GOAT POX AS A SOURCE OF "VACCINE LYMPH."

Goats are subject to an eruptive disease, which is alleged to be similar to Small Pox in man.

Dr. Valentine and others proved that it was possible to vaccinate the goat and to retro-vaccinate the human subject; and Professor Heydeck, at Madrid, meeting with an outbreak of an eruptive disease of goats known as Goat Small Pox, and influenced, no doubt,. by the doctrine that vaccine lymph was derived from Cow Small Pox, proposed to employ the lymph from this source to afford human beings protection from Small Pox. A friend of Mr. Dunning received the following letter briefly referring to these experiments :l—

> " Madrid, March 9th, 1804.
> " I am not able to send you, at present, our observation on the Goat Pock subsequent to the 8th of June last, because it is not finished yet; for the king ordered in September last that all the children in the Foundling-house, and those who are in the Desamparados should be inoculated with the Goat Pock, which did its effects ; we are now employed in the contra-proofs, and after everything is finished, shall send the whole process to you for the inspection of your medical friends and Dr. Jenner; and as I am at present on another discovery, not less useful than the Goat Pock, I shall give also an account of its results in my next letter."

> 1 Baron, loc. cit.

His friend replied:—

> " I wrote to the Professor about three weeks ago, told him that his discovery had excited very much the attention of the medical world in England, and more immediately Dr. Jenner's, and urged him to forward his further observations with all the expedition in his power, and that I would transmit them to you."

Mr. Dunning published an account of these experiments, but Jenner discountenanced the idea. In a letter to Mr. Dunning, he wrote:—

> " I believe we have had no correspondence since your Spanish paper appeared in the Medical and Philosophical Journal. To be plain with you, and use the familiarity of a friend, I do not like it. The paper is not now before me; but if I recollect right, it went only to prove that goats are subject to spontaneous pustules upon their nipples; that the matter of these pustules was inserted into the arms of human subjects; and that it produced local effects. Is there any quadruped that is not subject to diseased nipples? Even the human animal, we know from sad experience, is not exempted. The cow, like other animals, is subject to a spontaneous pock upon its teats, the fluid of which, when brought in contact with the denuded living fibre, is capable of exciting disease; but I positively assert, this is not one grand preventive. When you hear again from Madrid, do not fail to tell me what the Spaniards say about it. I have already anticipated."

And in a postscript he added:—

> " Do not fail to write soon. I want to know your further sentiments of the Goat Pox."

I have not been able to ascertain whether any further experiments were made at the time, or what became of the stock of goat lymph "which did its effects." Nor have I been able to obtain the history of similar experiments with any diseases of the goat, in more recent times.
CHAPTER 13.
COW POX AS A SOURCE OF " VACCINE LYMPH. "

The description given by Jenner in the Inquiry, was the first published account of Cow Pox. He described the disease in the cow as consisting of irregular pustules on the teats, of a palish blue colour, surrounded by an erysipelatous inflammation, and characterised by a tendency to degenerate into phagedenic ulcers. The animals were indisposed, and the secretion of milk lessened.

This description is not so complete as that given, a few months afterwards, by Clayton,1 a veterinary surgeon in Gloucester, and published by Mr. Cooke.

> " The Cow Pox begins with white specks upon the cow's teats, which, in process of time, ulcerate, and if not stopped, extend over the whole surface of the teats, giving the cow excruciating pain :—that if this disease is suffered to continue for some time, it degenerates into ulcers, exuding a malignant and highly corrosive matter; but this generally arises from neglect in the incipient stage of the disease, or from some other cause he cannot explain :—that this disease has not a regular process of commencing and terminating without a remedy, because, if not attended to, it would end in a mortification

> 1 Cooke. Contributions to Physical and Medical Knowledge, collected by Thomas Beddoes, p. 392. 1799-
> of the teats, and probably death of the animal :—that this disease may arise from any cause irritating or excoriating the teats, but the teats are often chapped without the Cow Pox succeeding. In chaps of the teats, they generally swell; in the Cow Pox, the teats seldom swell at all, but are gradually destroyed by ulceration:—that this disease first breaks out upon one cow, and is communicated by the milkers to the whole herd, but if one person was confined to strip the cow having this disease, it would go no farther:—that the Cow Pox is a local disease, and is invariably cured by local remedies:—that he never knew this disease extend itself in the slightest degree to the udder, unless mortification had ensued, and that he can at all times cure the Cow Pox in eight or nine days, by his usual local remedies :—that he is conversant with the diseases of the horse, and extensively employed, particularly in curing the Grease :—that he cannot recollect ever to have had horses with the Grease and cows with the Cow Pox, under cure at the same time, and at the same farm:—that he is very certain he has frequently had cows with the Cow Pox, where no horses whatever have been kept:—that he considers the Grease as a name, having great latitude in the diseases of horses, because sometimes it may be cured merely by topical remedies, and at other times it is only to be completed by internal remedies:—that he does not consider the Grease an infectious disease amongst horses, since greasy horses and horses in perfect health frequently stand in stables together indiscriminately, without infecting each other ; and although it is probable, if the discharge of Grease was to be applied in its most acrid state to the heels of a sound horse, it would inflame and excoriate them, yet it would not produce the Grease :—that Grease is most prevalent in winter, at which time he has never known the Cow Pox to occur, and therefore cannot think it at all probable that the Grease can have the least influence in producing the Cow Pox."

Mr. John Sims,1 in a letter dated February 13th, 1799, corroborated the account given by Clayton.

1 Sims, Medical and Physical Journal. 1799.

> "There is a gentleman of eminence in the law, now living at Bristol, who has had the Cow Pox thrice, and being afterwards inoculated for the Small Pox, had it in so great abundance that his life for some time was despaired of. He describes the Cow Pox as the most loathsome of diseases, and adds that his right arm was in a state of eruption both the first and the second time from one extremity to the other; the pain was excessive, and his fingers so stiff he could scarcely move them. The gentleman alluded to was the son of a farmer who kept seventy cows, of which he, being then a lad, milked eighteen himself; they were all of them infected with this disorder at one time; he caught it, and such was the abhorrence it created in the family that they made no use of the milk as long as it lasted. He never heard, nor does he believe, that this complaint originates, as supposed by Dr. Jenner, from any communication with that acrid humour called the grease in horses."

Dr. Bradley, one of the editors of the Medical and Physical Journal, commenting on this case, says :—

> " What this gentleman remarks of the loathsomeness of the disease, although a circumstance overlooked in Dr. Jenner's account, appears to be in itself a formidable objection, should it be found to answer the purpose for which it has been recommended."

Dr. Bradley, in the same paper, briefly referred to the outbreak of Cow Pox which occurred in London in February 1799, and gave a coloured plate of the disease on the arm and fingers of a milker. The Cow Pox, he adds, in this instance, "appears to have been very mild, for no loss was experienced by the farmers from the deficiency of milk as usually happens."

This early description was supplemented by an account of Cow Pox1 by Mr. Lawrence, author of A Philosophical and Practical Treatise on Horses and on the Moral Duties of Man towards the Bride Creation. This article on Cow Pox not only affords further evidence of this disease being known to those who had the care of cattle, before Jenner's paper was published, but it shows that it had also been made the subject of practical observation and study, by veterinary surgeons.

1 Med. and Phys. Journ, vol. ii., p. 113. April 1799.

Lawrence was of opinion that the disease had no connection with grease, and thus relates his experience :—

> " Concerning the real aetiology of the disease, I have, for many years, been without any uncertainty in my opinion. Too sudden repletion and thickening of the fluids, after the fatigue of long driving and inanition is an auxiliary and accelerating cause of Pox upon the teats, accompanied by low fever, considerable debility, and a diminution both of the quantity and quality of the milk. This hypothesis, I think, will at least not be condemned as irrational, when it is considered that the disease is nearly or altogether unknown, except in the dairy counties, and in large towns where the animals which are its victims are congregated in such great numbers and stowed so close.
> " That it is often taken in so slight a way as to have no preventive effect of the Small Pox, I apprehend pretty numerous proofs might be obtained.
> " The Pox among cows I always supposed to arise from the contagion of their own atmosphere ; a cause fully adequate to the effect produced ; and this effect ceases with the cause or from the influence of some casual and unknown cause, and is reproduced indefinitely with the recurrence of the original cause.
> " Whatever may be the fate of Cow Pox inoculation it has and will give further occasion to a pretty large and open discussion, which is always beneficial, as having a tendency to produce discovery and promote improvement, and when the public ardour for the present topic shall have become a little cool and satisfied, I hope it will be turned by enlightened men towards another, perhaps of nearly as great consequence, namely, the prevention of the original malady in the animals themselves. Those who had witnessed it and only reflected upon the excessive filth and nastiness which must unavoidably mix with the milk in an infected dairy of cows, and the corrupt and unsalubrious state of their produce in consequence, will surely join me in that sentiment."

Lawrence was almost a century before his time. Cow Pox was not again brought forward in this light until 1887-88, when I reported the "filth and nastiness" at a Wiltshire Farm, and advocated the advisability of placing this disease under the Contagious Diseases (Animals) Act.

Characters of the Disease in the Cow.

The numerous details, wanting in the early accounts of Cow Pox, have been supplied by the painstaking and laborious researches of Robert Ceely.1 From his classical papers in the Transactions of the Provincial Medical Journal, we have a complete picture of the features of the natural disease in the cow.

1 Vide vol. ii., p. 363, et seq.

> In Ceely's experience in the Vale of Aylesbury, outbreaks occurred at irregular intervals, most commonly appearing about . the beginning or end of the spring; rarely during the height of summer. There were outbreaks at all periods, from August to May and the beginning of June; cases also being met with even in autumn and the middle of winter, after a dry summer. The disease was occasionally epizootic, or occurring at times in several farms at no great distance from each other, but more commonly sporadic or nearly solitary. It was to be seen sometimes at several contiguous farms ; at other times, at one or two farms. Many years might elapse before it occurred at a given farm or vicinity, although all the animals might have been changed in the meantime. Cow Pox had 'broken out twice in five years in a particular vicinity, and at two contiguous farms, while at a third adjoining dairy, in all respects similar in local and other circumstances, it had not been known to exist for forty years. It was sometimes introduced into a dairy by recently purchased cows. Twice it had been known to be so introduced by milch heifers. It was considered that the disease was peculiar to the milch cow; it came primarily while the animal was in that condition, and it was casually propagated to others by the hands of the milkers. Sturks, dry heifers, dry cows, and milch cows milked by other hands, grazing in the same pastures, feeding in the same sheds, and at contiguous stalls, remained exempt from the disease.
> For many years past, however, the spontaneous origin of Cow Pox had not been doubted in the Vale of Aylesbury. In all the cases that Ceely had noticed he never could discover the probability of any other source.
> Condition of Animals primarily affected.—There was much difficulty in determining with precision at all times, whether this disease arose primarily in one or more individuals in the same dairy. Most commonly, however, it appeared to be solitary. The milkers believed that they were able to point out the infecting individual. In two instances, there could be very little doubt on this point. In August 1838 three cows were affected with the disease. The first was attacked two months after calving and seven weeks after weaning. This animal was considered to be in good health, but it locked out of condition. She had heat and tenderness of teats and udder as the first noticed signs. The other two were affected in about ten days. In December 1838, in a large dairy, a milch cow slipped her calf, had heat and induration of the udder and teats, with vaccine eruption, and subsequently leucorrhoea and greatly impaired health; the whole dairy, consisting of forty cows, and some of the milkers, became subsequently affected. In another dairy, at the same time, it first appeared in a heifer soon after weaning, and in about ten or twelve days, extended to five other heifers and one cow, milked in the same shed, and it also affected the milkers. In another dairy, at the same time, thirty cows were severely affected, and also one of the milkers. It appeared to arise in a cow two months after calving. The only symptoms noticed were that the udder and teats were tumid, tender, and hot, just before the disease appeared.
> Condition of Animals casually affected.—In some animals the attack was less severe than in others, depending on the state and condition of the skin of the parts affected, and the constitution and habits of the animal. It was sometimes observed to diminish the secretion of milk, and in most cases it commonly did affect the amount obtained artificially; with this exception, and the temporary trouble and accidents to the milk and the milkers, little else was observed; the animal continued to feed and graze apparently as well as before. The topical effects varied very much in different individuals, the mildness or severity being greatly influenced by temperament and condition of the animal, and especially by the state of the teats and udder, and the texture and vascularity of the skin of the parts affected. Where the udder was short, compact, and hairy, and the skin of the teats thick, smooth, tense, and entire, or scarcely at all chapped, cracked, or fissured, the animal often escaped with a mild affection, sometimes with only a single vesicle. But where the udder was voluminous, flabby, pendulous, and naked, and the teats long and loose, and the skin corrugated, thin, fissured, rough, and unequal, then the animal scarcely ever escaped a copious eruption. Hence, in general, heifers suffered least and cows most from the milkers' inoculations and manipulations.
> Progress of the Disease.—Cow Pox, once arising or introduced, and the necessary precautions not being adopted in time, appeared in ten or twelve days, on many more, in succession, so that among twenty-five cows perhaps by the third week nearly all would be affected ; but five or six weeks or more were required to see the teats perfectly free from the disease.
> Propagation by the Hand of the Milker.—Ceely was able to confirm the way in which the disease was said to spread. In December 1838, on a large dairy farm, where there were three milking-sheds, Cow Pox broke out in the home or lower shed. The cows in this shed being troublesome, the milker from the upper shed, after milking his own cows, came to assist in this for several days, morning and evening, when, in about a week some of his own cows began to exhibit the disease. It appears that, having chapped hands, he neglected washing them for three or four days at a time, and thus seemed to convey the disease from one shed to another. During the progress of the disease through this shed, one of the affected cows, which had been attacked by the other cows, was removed to the middle shed, where all the animals were perfectly well. This cow, being in an advanced stage of the disease, and of course difficult to milk and dangerous to the milk pail, was milked first by a juvenile milker for three or four days only, when, becoming unmanageable by him, her former milker was called in to attend exclusively to her. In less than a week all the animals of this shed showed symptoms of the disease, though in a much milder degree than it had appeared in the other sheds, fewer manipulations having been performed by an infected hand.
> Topical Symptoms of the Natural Disease.—For these, Ceely was almost always, in the early stage, compelled to depend on the observations and statements of the milkers. They stated that for three or four days, without any apparent indisposition, they noticed heat and tenderness of the teats and udder, followed by irregularity and pimply hardness of these parts, especially about the bases of the teats, and adjoining the vicinity of the udder; that these pimples on skins not very dark were of a red colour, and generally as large as a vetch or a pea, and quite hard, though in three or four days many of these increased to the size of a horse-bean. Milking was generally very painful to the animal; the tumours rapidly increased in size, and some appeared to run into vesication on the teats, and were soon broken by the hands. Milking now becomes a troublesome and occasionally a dangerous process.
> Ceely adds :—" It is very seldom that any person competent to judge of the nature of the ailment has access to the animal before the appearance of the disease on others of the herd, when the cow first affected, presents on the teats acuminated, ovoid, or globular vesications, some entire, others broken, not infrequently two or three interfluent; those broken have evidently a central depression with marginal induration ; those entire, being punctured, diffuse a more or less viscid amber-coloured fluid, collapse, and at once indicate the same kind of central and marginal character. They appear of various sizes, from that of a pin's head, evidently of later date, either acuminated or depressed, to that of an almond or a filbert, or even larger. Dark brown or black solid uniform crusts, especially on the udder near the base of the teats, are visible at the same time, some, much larger, are observed on the teats; these, however, are less regular in form and less perfect. Some are nearly detached, others quite removed, exhibiting1 a raw surface with a slight central slough. On the teats, the crusts are circular, oval, oblong, or irregular; some flatter, others elevated ; some thin and more translucent, being obviously secondary. The appearance of the disease in different stages, or at least, the formation of a few vesicles at different periods, seems very evident. The swollen, raw, and encrusted . teats seem to produce uneasiness to the animal only while subjected to the tractions of the milkers, which it would appear are often nearly as effectual as usual." Referring again to the character of the vesicles, Ceely says that those "fortunate enough to have an opportunity of watching the disease in its progress may observe that when closely examined they present the following characters :—In animals of dark skin, at this period, the finger detects the intumescent indurations often better than the eye, but when closely examined, the tumours present, at their margins and towards their centres, a glistening metallic lustre or leaden hue ; but this is not always the case, for occasionally they exhibit a yellowish or yellowish-white appearance."
> In describing more fully the crust, Ceely said that "large black solid crusts, often more than an inch or two in length, are to be seen in different parts of these organs, some firmly adherent to a raw elevated base, others partially detached from a raw, red, and bleeding surface; many denuded, florid, red, ulcerated surfaces, with small central sloughs secreting pus and exuding blood, the teats exceedingly tender, hot, and swollen. ... In some animals, under some circumstances, this state continues little altered till the third or fourth week, rendering the process of milking painful to the animal, and difficult and dangerous to the milker." 1
> "In many, however, little uneasiness seems to exist. The parts gradually heal; the crusts, although often partially or entirely renewed and renewed, ultimately separate, leaving apparently but few deep irregular cicatrices, some communicating with the tu-buli lactiferi, the greater part being regular, smoothly-depressed, circular, or oval."
> With regard to papulae, "the milkers seldom notice the first period of papulation. Nor is this to be wondered at. It is, in truth, very difficult for an experienced observer, at all times, to escape error in this latter particular, and oversights will occur to the most vigilant from various causes, especially from peculiarity of colour, vascularity and texture of skin, as well as temperament of the individual."
> With regard to central depression of the vesicles, Ceely found that " in three or four days from their first appearance the papulae acquire their vesicular character, and have more or less of central depression, continuing gradually to increase. In three or four days more, they arrive at their fullest degree of development, and sometimes are surrounded with an areola, and always embedded in a circumscribed induration of the adjacent skin and subjacent cellular tissue."

> 1 Compare Plate X.

If we carefully analyse this description of Cow Pox, we find that we have a most faithful account of the disease, as it actually occurred under Ceely's eyes. But, here and there, we see an attempt to harmonise these observations with the classical description of the inoculated disease. In ordinary vaccination, we recognise the stages of the papule, the vesicle with its central depression, the scab, and the scar. And Ceely, it will be observed, describes the natural Cow Pox under each of these headings. But when describing the vesicles, he practically admits that the classical character of umbilication is absent, for he says that those broken had evidently a central depression ; and again, that vesicles, three or four days after the appearance of papules, have more or less of a central depression.

There can be little doubt that in the use of these ambiguous expressions, Ceely was probably misled by constantly having in his mind the effects of ordinary vaccination. And the appearances depicted in the elaborate pictures of Cow Pox on the cow's teats, which illustrate his classical memoir, can therefore be explained. The second plate is a faithful picture of the disease on the teats as it is ordinarily met with. [Plate IX.] The first plate is apparently a composite picture, representing the eruption as ordinarily observed in the cow, and a number of depressed vesicles as they appear after artificial inoculation. The. outline of this drawing is, I am of opinion, distinctly after Sacco. It is, however, an improvement on the latter, which can only be described as an imaginary diagram, representing the udder and teats of a cow, covered with an eruption purporting to be that of the natural Cow Pox. Jenner had described the vesicles in natural Cow Pox, as possessing a bluish tint, and Sacco deliberately represents the natural disease by a drawing of clusters of vesicles of inoculated Cow Pox, coloured bright blue, and with a silvery lustre. Ceely has outlined his drawing from Sacco's, but he has represented the crusts and scabs on the teats as he really saw them, though he has unfortunately added the vesicular stage, as he always wished to see it. I say unfortunately, for while Sacco's plate was accepted as a genuine representation of the natural disease in the cow for the first half of this century, Ceely's plate has been accepted (particularly in this country) for the latter half. It has, to my knowledge, been used in a veterinary school to represent what Cow Pox would be like, if it were ever again discovered!

Hering has given a coloured plate of the natural Cow Pox, and it will be noticed that it is totally different from either Sacco's or Ceely's drawing. On the teats are a number of oval or circular bullous vesicles and crusts. More recently, Layet has pointed out the same character in the Cow Pox discovered at Cerons in 1883. The characters of the inoculated disease were wanting, particularly the central depression of 'the vesicle. In Wiltshire I could only distinguish on the cow's teats, globular and broken vesicles, thick prominent crusts and ulcers; appearances which had very little in common with the characters of the inoculated disease.

Casual Cow Pox on the Hands of Milkers.

The early accounts of the " loathsome" character of the disease will appear by no means exaggerated to those, who have had an opportunity of studying its effects on the hands of milkers, or indeed to those who have made themselves familiar with the descriptions given by Jenner and others. To illustrate this, I will briefly refer to some of Jenner's cases :—

> " Joseph Merret had several sores on his hands: swelling and stiffness in each axilla, and much indisposition for several days.
> " Mrs. H. had sores upon her hands, which were communicated to her nose, which became inflamed and very much swollen.
> " Sarah Wynne had Cow Pox in such a violent degree that she was confined to her bed, and unable to do any work for ten days.
> " William Rodway was so affected by the severity of the disease that he was confined to his bed.
> " William Smith had several ulcerated sores on his hands, and the usual constitutional symptoms, and was affected, equally severely, a second and a third time.
> "William Sttnchcomb had his hand very severely affected with several corroding ulcers, and a considerable tumour in the axilla.
> " Sarah Nelmes had a large pustulous sore on the hand and the usual symptoms.
> "A girl had an ulceration on the lip from frequently holding her finger to her mouth to cool the raging of a Cow Pox sore by blowing upon it.
> " A young woman had Cow Pox to a great extent, several sores which maturated having appeared on the hands and wrists.
> "A young woman had several large suppurations from Cow Pox on the hands."

Pearson met with similar experiences in his investigations, and was informed of others.

> '' Thomas Edinburgh was so lame from the eruption of Cow Pox on the palm of the hand, as to necessitate his being for some time in hospital. For three days he had suffered from pain in the armpits, which were swollen and sore to the touch. He described the disease as uncommonly painful, and of long continuance.
> "A servant at a farm informed Pearson that in Wiltshire and Gloucestershire, the milkers were sometimes so ill as to lie in bed for several days.
> " Mr. Francis said that Cow Pox was very apt to produce painful sores on the hands of milkers.
> "A servant of Mr. Francis said that Cow Pox affected the hands and arms of the milkers, with painful sores as large as a sixpence.
> " Mr. Dolling described the disease as a swelling under the arm, chilly fits, etc., not different from the breeding of the Small Pox. After the usual time of sickening, namely, two or three days, there is a large ulcer not unlike a carbuncle, which discharges matter.
> " Dr. Pulteney described the disease as causing ' a soreness and swelling of the axillary glands as under inoculation for the Small Pox, then chilliness and rigors and fevers, as in the Small Pox.' Two or three days afterwards, abscesses, not unlike carbuncles, appear generally on the hands and arms, which ulcerate and discharge much matter.
> "Mr. Bird wrote a short account of Cow Pox, 'It appears with red spots on the hands, which enlarge, become roundish, and suppurate, tumours take place in the armpit, the pulse grows quick, the head aches, pains are felt in the back and limbs, with sometimes vomiting and delirium.'
> "Annie Francis had pustules on her hands from milking cows. These pustules soon became scabs, which, falling off, discovered ulcerating and very painful sores, which were long in healing. Some milk from one of the diseased cows, having spurted on the cheek of her sister and on the breast of her mistress, produced, on these parts of both persons, pustules and sores similar to her own on her hands.''

Pearson classified the cases of which he had received information into :—

1. Those in which the patients are inflicted with so much painful inflammation as to be confined to their beds for several days, and have painful phagedenic sores for several months.
2. Those cases which are so slight that the patients are not confined at all, but get well in a week or ten days.

I will now proceed to point out that, in more recent times, these descriptions have been confirmed.

In 1836, Cow Pox was discovered at Passy, near Paris, and was investigated by Bousquet.1 A cow had Cow Pox six weeks after calving. Bousquet had no opportunity of seeing the eruption in the early stage, but at the time of his examination, he found reddish-brown crusts on the teats, which later gave place to puckered scars. The milk-woman, Fleury, who had had Small Pox, nevertheless contracted the disease from the cow. She had several vesico-pustules on the right hand and on her lips. A vesico-pustule on her hand, when opened with a lancet, discharged like an abscess.

Ceely,2 in 1840-42, very fully described the casual disease in milkers :—

> 1 Vide vol. ii., p. 312.
> 2 Ceely, loc. cit.

> " As in the cow so in man, it does not appear always necessary that the skin should be visibly fissured or abraded to insure infection, although very often we find those conditions in existence. A thin and vascular skin seems capable of absorbing lymph, if copiously applied and long enough retained. The parts upon which the disease is commonly observed are the back of the hands, particularly between the thumb and forefinger, about the flexures of the joints and on the palmar, dorsal, and lateral aspects of the fingers. The forehead, eyebrows, nose, lips, ears, and beard, are often implicated from incautious rubbing with the hands, during or soon after milking. In women, the wrists and lower parts of the naked forearm coming in contact with the teats are apt to be affected. If the skin of the hands be very thin and florid, especially if chaps and fissures abound, the individual often suffers severely, having, soon after the decline of the disease, abscesses and sinuses of the subcutaneous cellular tissue and often considerable swelling and inflammation of the absorbents and the axillary glands. The inflamed spots or papulae which announce the disease are more circumscribed, better defined, harder, deeper, and more acuminate, than the papulae produced by some of the other contagious eruptions of the cow. They vary in colour from a deep rose to a dark damask or purple hue, according to the vascularity and texture of the parts affected. If the papulae be small, there is often no perceptible central depression in the early period of their change to the vesicular state; but they exhibit an ash-coloured or bluish, rather acuminated apex, which gradually becomes relatively flatter as the base enlarges and elevates, when the central depression is more obvious and exhibits a yellowish tinge.
> " Larger vesicles, especially on the back of the hand and sides of the fingers, have a well-marked central depression in the early stage, and often a livid or irregularly ecchymosed appearance similar to what is observed on the cow; when fully developed, they present a bluish or slate-coloured hue, which increases in depth, and is more conspicuous towards their decline. This bluish colour, though very common, is often absent, even in some of the vesicles on the same hand. It evidently depends upon and is influenced by the vascularity of the part, the greater or less translucency of the epidermis, the quantity of lymph, the depth and extent of the vesicle. When the epidermis is stripped off from such vesicles, the zone-like adventitious membrane appears diaphanous, and has a bluish or livid hue, derived, doubtless, from the highly congested state of its vessels; here and there, are often seen spots of actual ecchymosis. Where the epidermis is thick, the vesicles are generally well defined, circular, or oval, if the parts will admit, and have only a slight slate-coloured tint in the centre, but more frequently this colour is superseded by an opaque white or a dusky yellowish hue. Where the skin is loose, thin, dark, or dusky, the vesicles are jagged, irregular and puffed at their margins, and, saving the central depression, very much resemble a scald. In size they vary from that of a vetch to a fourpenny-piece, sometimes larger, especially when depending on a wound or extensive fissure. The vesicles are frequently broken, or, when the epidermis is thin, spontaneously burst, causing deep sloughing of the skin and cellular tissue and ulcerations, which slowly heal. There is often, consequently, much attendant local irritation and considerable symptomatic fever.
> " Papular, vesicular, and bullous eruptions are occasionally seen attendant on casual Cow Pox, especially in j'oung persons of sanguine temperament and florid complexion, at the height or after the decline of the disease. They are generally of the same character as those known to attend the inoculated disease; but now and then we are told by the patients that these eruptions, either solitary or in clusters, resemble the vaccine vesicles.
> "Although the casual Cow Pox in man is mostly found in those who have not previously gone through variola or the vaccine, it is by no means rare to meet with it on persons who have passed through the latter and a few who have had the former disease."

To illustrate this account of casual Cow Pox in man, I will give the particulars of cases observed by Ceely, in October, 1840.

> " I. Mr. Pollard, aet. fifty-six. When first observed, the vesicles on the hand and finger had burst, the secondary constitutional symptoms were declining, and the centres of the vesicles, as usual, were in a sloughing state. About ten days after the discovery of the disease on the cows, the patient observed two itching small pimples on the site of the present ulcers, which, according to his account, ran the normal course of the vaccine vesicle; as soon as the areolas commenced, having felt scarcely any indisposition before, pain and tenderness of the axillary glands, with the usual constitutional symptoms, arose, and gradually increased for four or five days, but were never severe enough to confine him to the house. When seen later the topical inflammation was rapidly departing, the vesicles were quite broken up, and a blackish-brown slough, adhered to their centres, their base being surrounded with an elevated induration of a hard red colour.
> " II. Joseph Brooks, aet. seventeen, felt the glands and lymphatics of his neck stiff and tender; and noticed a pimple on the temporo-frontal region, which he could not resist scratching. He also observed a red pimple on his finger, of the size of a pin's head, and one very small one on the thumb. In neither situation was there to his knowledge any visible wound or abrasion of the cuticle.
> "On the 21st, he had headache, general uneasiness, and pains of the back and limbs, with tenderness and pain in the course of the corresponding lymphatic vessels and absorbent glands, particularly of the axilla, which increased till the 23rd, when nausea and vomiting took place. His right eyelids became swollen, and were closed on that day; but after this period he became better in all respects, never having been confined to the house, although disabled from work. The engravings [Plates XL, XII.] represent the vesicles as they appeared on the 23rd, when the constitutional and local symptoms were subsiding. The vesicle on the temporal region had a well marked central depression, with a slight crust, a general glistening appearance, and was of a bright rose or flesh colour, with a receding areola; and there was an inflamed, tumid, and completely closed state of the corresponding eyelids.
> " On the finger, the vesicle was small and flat, with a slightly depressed centre, containing a minute crust. It had a beautiful pearly hue, and was seated on a bright rose-coloured slightly elevated base. On the thumb, the vesicle was also flat and broad, but visibly depressed towards the centre, where there appeared a transverse linear-shaped crust, corresponding, doubtless, with a fissure in the fold of the cuticle. The vesicle was of a dirty yellowish hue, and visibly raised on an inflamed circumscribed base. Lymph was obtained from the vesicle on the temple, in small quantity, by carefully removing the central crust, and patiently waiting its slow exudation. In this, as in most other respects, it strikingly resembled the vesicle on the cow, and appeared as solid and compact. The lymph was perfectly limpid, and very adhesive. No lymph was taken from the vesicles on the finger and thumb, with a view to avoid any interruption of their natural course.
> "On the 26th and 27th, when the redness and elevation of the base of the vesicles had materially diminished, the vesicles themselves had become greatly enlarged. On the thumb and finger, they were loosely spread out at the circumference, each having a dark and deep central slough. On the temple, the margin of the vesicle (as on the cow) was firm and fleshy, its diameter being nearly ten lines, and its centre filled with a dark brown firmly adherent slough. In about seven or eight days, with the aid of poultices, the sloughs separated, and the deep ulcers healed, leaving cicatrices like variola, deep, puckered, and uneven, which were seen on the 25th of November. The scar on the temple.was nearly as large on the 5th of December as the vesicle represented in the engraving.
> "Joseph White, aet. eighteen; fair complexion, thin skin. Had never before had variola or vaccine. He had not been long engaged in milking at Dorton before he received the infection; he first noticed the pimples on the thumb and dorsum of the left hand on the 25 th of May. On the 30th, the sixth day of papulation,1 he first felt the mild constitutional symptoms and the axillary swelling and tenderness. The next day these symptoms increased ; but on the following day, the eighth of papulation, they abated ; yet as his hand was more painful, and he found himself incapable of work, he called on Mr. Knight for advice. Lymph was then abstracted and used by that gentleman; the areolag were just commencing. On the 2nd of June, the ninth

> 1. From our inability to determine the precise period of infection, we are obliged to reckon from the earliest period of recognised papulation.
> day of papulation, he came to Aylesbury, when the following appearances were observed. On the side of the thumb [Plate XIII.]. between the root of the nail and above the last articulation, was a flat vesicle of a dirty white hue, with a slight central discolouration rather than depression, and a pale red areola extended around the vesicle and beyond the last joint of the thumb. On the back of the hand there was a smaller vesicle, of a different colour and character; it was visibly raised, overlapping at the outer margin, and depressed in the centre, on a less circumscribed but obvious base. The vesicle was of a light flesh colour; its central crust dark brown, and a moderate light rose-coloured areola, and some tumefaction surrounded and raised the whole. A small red imperfectly vesiculated pimple was seen on the left cheek—noticed by the patient now for the first time. The axillary glands and absorbent vessels were very tender; and though early in the morning the patient felt generally better, in the evening there was increase of all the symptoms.
> "June 3rd, tenth day of papulation. — To-day worse in all respects; both vesicles considerably enlarged, and the areolse much increased. There was considerable tumefaction of the thumb and the back of the hand; and the absorbent vessels, highly inflamed, could be traced by the eye into the axilla.
> "June tth, eleventh day of papulation.—The vesicles enlarging areolae rapidly subsiding; constitutional symptoms less in the morning, but in the evening augmented ; the areolae then quite gone, but much puffiness of integuments remaining ; and some red absorbents still visible on the arm. The vesicle on the face now contains a light amber crust.
> "June 5th, twelfth day of papulation.—Better in all respects; less tumefaction of the hand, etc.; vesicles expanding. That on the thumb was of a dull dirty white horn-colour, and it had still a dull red areola around the raised and tumid base; the centre of the vesicle, scarcely depressed, was of a dirty yellowish-brown colour. On the hand the vesicle was of a dull pearly hue, though rather more glistening than before; it was much puckered at the centre and the margin: the centre was deeply depressed, and contained a small dirty yellowish-brown crust. The areola was dull, and brighter than that on the thumb.
> "June 8th, fifteenth day of papulation.—The vesicle on the thumb [Plate XIV.] was still characteristic, though it had acquired a vesicated margin. The vesicle on the hand [Plate XIV.] was also characteristic, though puffed exceedingly at its circumference. The vesicle on the face was now capped with a hard light brown crust [Plate XIV.].
> "June 12th, nineteenth day of papulation.—The stage of ulceration was fully developed [Plate XIV.], and the extent of topical disorganisation was now sufficiently manifest.
> " In about a fortnight, the ulcers were perfectly healed, leaving scars like those succeeding variolse or any other disease attended with entire destruction of the corium."

In a letter to Mr. Badcock, dated April 3rd, 1845, Ceely, referring to a new stock of lymph raised from a milker's hand, wrote :—

> " In the enclosed lymph I see nothing unusually severe, except on very thin skins, although the milker's hand exhibits now rough ulcers, one on the hand deep enough to encase a bean."

After Ceely's cases in 1840-41, no cases of casual Cow Pox on the hands of milkers, in this country, were recognised as such and recorded for nearly fifty years. In December 1887, Cow Pox broke out on farms near Cricklade in Wiltshire, and the disease was communicated to nearly all the milkers.

> John Rawlins, milker, informed me that he was the first to catch the eruption from the cows. He states that it came as a hard, painful spot, which formed "matter" and then a "big scab." He had been inoculated about seven weeks ago. He pointed to the scar which remained on his right hand. This scar presented the characters of an irregular cicatrix, indicating considerable loss of substance. He states that he had also two places on his back, where he supposes he had inoculated himself by scratching. He had continued milking ever since, but had had no " fresh places."
> William Hibbert, milker. He states that he was inoculated from the cows about the same time as J. R. They were the two milkers of the herd in which the Cow Pox first made its appearance. The eruption appeared in one place on each hand. He pointed to two irregular scars as the remains of the eruption.
> Joseph Lanfear, milker, states that he also caught the disease from the cows. On his right hand, " a spot appeared which formed a blister, then discharged matter, and produced a bad sore." Lumps formed at the bend of his elbow and in his armpit. He lost his appetite, felt very poorly, and was obliged to leave off work for two or three days, and stay at home.
> He states that about a fortnight or three weeks afterwards, while milking a very bad case, a sore on his left hand, resulting from a wound with a rusty nail, became inflamed, and another place broke out at the tip of one of his fingers, but he was not poorly, nor did lumps appear in his left armpit.
> William King works on the farms, but was put on as a milker to take the place of one of the others with bad hands. After his fifth or sixth milking, that is to say about three days after first milking the cows, pimples appeared on his hands, which became " blistered and then ran on to bad sores." He pointed to three irregular scars on the first and third fingers and palm of the right hand. Lumps appeared in his elbow and in his armpit, but he did not feel very poorly in consequence.
> James Febry, milker, states that about a month ago he noticed spots which appeared on both hands. His fingers swelled and were painful. He says it came first like a pimple and felt hard. Then it " weeped out " water, in four or five days. There were red marks creeping up to his arm. There was a sort of throbbing pain, and he could not sleep at night.
> When I saw him, I found on the right hand a scar, but on the left hand, there was an ulcer about the size of a shilling covered with a thick black crust. The crust was partially detached and exposed a granulating ulcer. It was, in this stage, the exact counterpart of the ulcers on the cow's teats.
> William Hibbert, jun., milker, states that he had both hands bad about a month ago. First the index finger of the left hand, and then the knuckle on the right hand and between the first and second fingers.
> He says that it came up like a hard pimple, and the finger became swollen and red. After a few days it " weeped out" water and then matter came away. Both his arms were swollen, but his left arm was the worst.
> About a fortnight after, he noticed kernels in his armpits, which were painful and kept him awake at night. His arms became worse, he could not raise them, and he had to give up milking. He also had had a " bad place" on the lower lip.
> On examination, I found that the axillary glands were still enlarged and tender. He volunteered the statement that the places were just like the sore teats. [Plate XVII., Fig. 4.]
> John Harding, the bailiff's son, also milked the cows. He had a sore on the upper lid of his right eye and on his left hand. In both cases, he had been previously scratched by a cat, and the scratches were inoculated from the cow's teats. The right hand also had been inoculated. The eruption broke out a fortnight ago. His hands were swollen, red, and hot. He felt very poorly and went to bed. Little spots like white blisters appeared on the back of his right hand. His mother remarked that they " rose up exactly as in vaccination." Thick dark brown scabs formed. He was very ill for two or three days, but did not send for a doctor. He had painful lumps at the bend of his arm and in the armpit. He gave up milking and had not taken to it since.
> On examining him, the thick crusts on his right hand were identical with the stage of scabbing in ordinary vaccinia. [Plate XV.]. The scabs fell off" in about three weeks to a month and left permanent depressed scars.
> William Plowman, milker. He had taken the place of one of the other milkers who had vesicles on his fingers and had been obliged to give up milking. After the seventh time of milking, he noticed a small pimple on his right cheek (Nov. 27th). The pimple became larger and, as he expressed it, " rose up like a blister."
> On December 2nd, the date of my visit, there was a depressed vesicle with a small central, yellowish crust and a tumid margin, the whole being surrounded by a well-marked areola and considerable surrounding induration. [Plate XVI., Fig. 1.]
> After puncturing the tumid margin and collecting clear lymph in a number of capillary tubes, I raised this central incrustation and observed a crater-like excavation, from which lymph welled up and trickled down the boy's cheek.
> On the following day, the crust had re-formed and was studded with coagulated lymph. The areola had become more marked, and on pricking the margin of the vesicle the contents were slightly turbid.
> From this day, the surrounding infiltration increased enormously, the whole cheek was inflamed, and the eyelids so cedematous that the eye was almost closed. There was enlargement of the neighbouring lymphatic glands. The crust, which had re-formed, thickened day by day, and on Dec. 9th, there was a thick reddish-brown crust, still bearing the character of central depression, situated on a reddened, raised, and indurated base. [Plate XVI., Fig. 2.]
> From this date, the surrounding induration gradually diminished. The crust changed in colour from dark-brown to black, and finally fell off on Dec. 15th, leaving an irregular depressed scar. This scar, when seen several months afterwards was found to be a permanent disfigurement.
> A vesicle also formed on the thumb of the left hand. Two days after the pimple appeared on his cheek, the lad says that he noticed a pimple on his thumb, and this, on my visit on Dec. 2nd, presented a greyish flattened vesicle, about the size of a sixpence. On the following day, its vesicular character was much more marked, and a little central crust had commenced to form. [Plate XVII., Fig. 1.] On Dec. 4th, especially towards the evening, the margins became very tumid, giving it a marked appearance of central depression. On Dec. 5th; I punctured the vesicle at its margin with a clean needle, and I filled a number of capillary tubes from the beads of lymph which exuded.
> On Dec. 7th, suppuration had commenced; the vesicle contained a turbid fluid, and the areola was well marked. [Plate XVII., Fig. 2.] On Dec. 9th the crust had assumed a peculiar slate-coloured hue, and, on pressing it, pus welled up through a central fissure. [Plate XVII., Fig. 3.] The areola had increased and there was considerable inflammatory thickening. The lymphatic glands in the armpit were enlarged and painful. Though there was deep ulceration, which left a permanent scar the ulceration did not assume quite so severe a character as in some of the other milkers. Possibly this may be accounted for to some extent by the fact that the pock was covered with a simple dressing, instead of being subjected to the irritation and injury incidental to working on the farm.
> There were in all eight milkers, varying in age from seventeen to fifty-five, who contracted the disease from milking the cows. Seven had been vaccinated in infancy, but not since; one had been revaccinated on entering the navy at fifteen. They were all vaccinated after complete recovery from the casual Cow Pox (that is to say, from three to four months afterwards), and were all completely protected. On the other hand, two milkers who had not had the casual Cow Pox were vaccinated, with the result in one of typical revaccination, in the other of very considerable local irritation.

Effects of Inoculation of Virulent Cow Pox Lymph.

Severe symptoms are not limited to milkers casually infected from the cow. Occasionally, intentional inoculation of fresh virus from the cow reproduces the disease without any mitigation. Thus in Jenner's cases1:—

> "James Phipps. The incisions assumed, at their edges, rather a darker hue than in variolous inoculation, and the efflorescence around them took on more of an erysipelatous look. They terminated in scabs and subsequent eschars.

> 1 Vide vol. ii., p. 172.
> " Susan Phipps was inoculated from the cow, by inserting matter into a superficial scratch, on Dec. 2nd.
> " 6th. Appearances stationary.
> " 7th. The inflammation began to advance.
> " 8th. A vesication perceptible on the edges, forming ... an appearance not unlike a grain of wheat with the cleft or indention in the centre.
> " 9th. Pain in the axilla.
> " 10th. A little headache; pulse 110; tongue not discoloured; countenance in health.
> "11th—12th. No perceptible illness; pulse about 100.
> " 13th. The pustule was now surrounded by an efflorescence interspersed with very minute pustules, to the extent of about an inch. Some of the pustules advanced in size and maturated. . . The child's arm now showed a disposition to scab, and remained nearly stationary for two or three days, when it began to run into an ulcerous state, and then commenced a febrile indisposition, accompanied with an increase of axillary tumour. The ulcer continued spreading nearly a week, during which, time the child continued ill, when it increased to a size nearly as large as a shilling. It began now to discharge pus ; granulations sprung up and it healed.
> " Mary Hearn, inoculated from the arm of Susan Phipps.
> "6th day. A pustule beginning to appear, slight pain in the axilla.
> " 7th. A distinct vesicle formed.
> " 8th. The vesicle increasing ; edges very red.
> " 9th. No indisposition ; pustule advancing.
> " 10th. The patient felt this evening a slight febrile attack.
> "11th. Free from indisposition.
> " 12 th and 13th. The same.
> " 14th. An efflorescence of a faint red colour extending several inches round the arm. The pustule, beginning to show a disposition to spread, was dressed with an ointment composed of hydrarg. nit. nib. and ung, cerae. The efflorescence itself was covered with a plaster of ung. hydr. fort. In six hours it was examined, when it was 'found that the efflorescence .had totally disappeared.' The application of the ointment of hydr. nit. rub. was made use of for three days, when the state of the pustule remaining stationary, it was exchanged for the ung, hydr. nit. This appeared to have a more active effect than the former, and in two or three days, the virus seemed to be subdued, when a simple dressing was made use of; but the sore again showing a disposition to inflame, the ung. hydrarg. nit. was again applied, and soon answered the intended purpose effectually."

Jenner's lymph was employed by Mr. Cline with similar results.

"The child sickened on the seventh day, and the fever which was moderate subsided on the eleventh. . . . The ulcer was not large enough to contain a pea."

But the lymph raised by Pearson and Woodville from the " mild " outbreak of Cow Pox in London produced a correspondingly mild effect. This was the result, for example, in the very first case inoculated by Woodville 1 from the cow.

> " Mary Payne, 3rd day. The inoculated part elevated and slightly inflamed.
> " 6th day. The local tumour extended to about one-third of an inch in diameter, and was nearly of a circular form, with its edges more elevated than its centre, and with the surrounding inflammation not greater than is usual in cases of inoculated Small Pox. The vesicle upon the middle of the tumour was now very large and distended with a limpid fluid.
> " 8th day. The redness surrounding the tumour seems returning, and the thirst and other febrile symptoms are much abated.
> " 9th day. She is perfectly free from complaint; the inoculated part is scabbing, but surrounded with a hard tumefaction of a bright red colour."

> 1 Vide vol. ii., p. 100.

Consequently Woodville, after describing two hundred cases of inoculated Cow Pox, wrote :—

> " We have been told that the Cow Pox tumour has frequently produced erysipelatous inflammation, and phagedenic ulceration, but the inoculated part has not ulcerated in any of the cases which have been under my care, nor have I observed inflammation to occasion any inconvenience except in one instance, when it was soon subdued by the application of aqua lithargyri acetati."

Similar experiences have been encountered since, in the early removes of fresh stocks of virulent lymph. Bousquet,1 in 1836, in the first trials with his new lymph, made three punctures, but he had soon to abandon this practice, because the intensity of the inflammation was sometimes so great that it spread over the arm and into the axilla. In one case, the vesicles were enormous, and the inflammation so violent that baths, poultices, fomentations, and antiphlogistic diet scarcely sufficed to reduce it. The crusts when they tell off, left ulcerations which were very slow to undergo cicatrization.

In some cases, the vesicles which resulted hollowed out the skin so deeply that they left regular holes.2

If was then that Bousquet appreciated Jenner's fears (les frayeurs de Jenner) and understood his anxiety to suppress the vesicle by every means in his power, including cauterisation.

The following year, Estlin,3 in England, started a

1 Vide vol. ii., p. 311.
2 Compare p. 426.
3 Vide vol. ii., p. 323.
stock of fresh vaccine virus from the cow, and soon found that the new lymph was extremely active.

> "Jane, inoculated from the hand of a milker, had three large fine prominent circular vesicles, and subsequently Estlin learnt that the child became 'very poorly.' Sarah Owens was inoculated with lymph from Jane.
> " Each vesicle was perfect, rising abruptly from the arm, its upper part almost overhanging the base; its surface was much flattened, and it yielded freely limpid fluid, when punctured before the areola appeared. On the thirteenth day, the child's body and extremities were covered with a rash in patches much elevated from the skin, and she was constitutionally indisposed. On the fifteenth day, the surface of the vesicle was becoming brown, and the areola, rash, and general indisposition had disappeared."

In contrasting this new lymph with the current lymph, Estlin said :—

> " The depth in the cellular membrane to which the vesicle extends is a marked feature in the new lymph. In some cases under my care, when during the third week the scab has been rubbed off, there have been deep, though not wide, circular cavities, that would have contained the whole of a peanut of the smallest size."

Estlin's lymph was employed on sixty-eight children by Messrs. Michell and Prankard, of Langport in Somersetshire, and the results which they reported to Estlin were :—

> In 52 the disease was regular.
> 1 Severe erysipelas.
> 4 Erythematous eruptions of a violent character.
> 2 Highly inflamed ulcerated arms.
> 1 No effect after twice vaccinating.
> 8 Result unknown; supposed to have been favourable.
> 68

In one of the patients, two months old, erythema appeared on the back, and gradually extended to the feet. The child had much dyspnoea, with croupy cough, and died on the 21st. Mr. Estlin's correspondent wrote : —

> " I do not attribute its death to vaccination, nor does the mother wholly, as she lost an infant previously with a similar affection of the air passages, but her neighbours set it down to vaccination entirely."

The case of erysipelas, and two more cases of erythema were serious. The attacks occurred during the first week, two of them on the day following vaccination.

The alarm caused by these violent symptoms was so great that Messrs. Michell and Prankard suspended the use of the new lymph.

Estlin supplied some of his lymph to the National Vaccine Establishment. Trials were made, but details were suppressed from publication, from which we may perhaps conclude that in some instances similar results to those experienced by the Langport practitioners were met with. The lymph was condemned, the practice of going back to the cow was discountenanced, and the Report insinuated (without mentioning his name) that Mr. Estlin was disseminating "spurious" Cow Pox.

> " We are sorry to hear an anxiety expressed that a recurrence should often be made to the disease of the cow which first supplied the genuine protective matter; for in the first place it is not in the nature of any other communicable virus to degenerate and lose its influence . . . and though we ourselves have taken a good opportunity more than once or twice of recruiting our stores with fresh genuine matter from the cow, yet we think it right to discourage an indiscriminate, imprudent resort to this experiment; because the animal is subject to more than one eruptive disease, and a slight mistake might possibly be made in the selection of the proper pustule by an inexperienced hand."

This Report received a severe castigation from the pen of Mr. Estlin.1 The lymph continued to be employed by practitioners all over this country, and having been mitigated by successive transmission through the human subject, was welcomed as " a great boon to the public and profession." It was also sent to America and other parts of the world.

1 Vide vol. ii., p. 345.

Effects of Inoculation of Mitigated Cow Pox Lymph.

When lymph has been attenuated or mitigated by careful selection and successive cultivation on the human arm, or the belly of the calf, it produces effects which are as follow:—About the end of the second day after insertion, or early on the third day, a slight papular elevation is noticeable. By the fifth or sixth day, it has become a distinct vesicle, of a bluish-white colour, with raised margin and central cup-like depression. The vesicle is perfect . by the eighth day, and is then circular, pearl-coloured, distended with clear lymph, with the central depression well marked. On the same day, or a little earlier, the areola begins to appear, and gradually extends to a diameter of from one to three inches, accompanied with induration and tumefaction of the subjacent connective tissue. After the tenth day, the areola begins to fade, and the vesicle at the same time begins to dry in the centre ; the lymph becomes opaque and gradually concretes, and by the fourteenth or fifteenth day, a hard mahogany-coloured scab is formed, which contracts, dries, blackens, and falls off between the twentieth and twenty-fifth day. A circular, depressed, foveated, and sometimes radiated, scar remains behind.

By selecting characteristic vesicles on the calf or the human subject, and by collecting the lymph at an early stage on the fifth, sixth, or seventh day, this artificial disease, described as vaccinia, can be propagated in this comparatively mild form. But under certain conditions, such as a peculiarity in the subject inoculated, or if lymph be taken too late, there will be,, just as in variolation, a tendency to revert to the full intensity of the natural virus.
CHAPTER 14.
" GREASE" AS A SOURCE OF " VACCINE .LYMPH."

Jenner included all spontaneous eruptions on the teats in the term "spurious Cow Pox." None of them were capable of yielding the "grand preventive." True Cow Pox, as he designated the source of his "vaccine lymph," was the eruption on the cow's teat which, according to a prevalent belief among farmers, originated from the grease. This disease was thus briefly described in Jenner's Inquiry.1

> "There is a disease to which the Horse from his state of domestication is frequently subject. The Farriers have termed it the Grease. It is an inflammation and swelling in the heel, accompanied at its commencement with small cracks and fissures, from which issues matter possessing properties of a very peculiar kind."

1 Vide vol. ii., p. 7.

If the men who dressed the horses' heels were called upon to milk cows, they communicated to them the malady known as the Cow Pox.

In support of these statements several cases were given.

> Case 1. Several horses belonging to a farm began to have sore-heels, which a man named Merret attended to. He milked the cows. They soon became affected with Cow Pox, and several sores appeared on his hands.
> Case 2. One of the horses on a farm had sore-heels, and it fell to the lot of William Smith to attend to the animal. By these means the infection was carried to the cows, and from the cows it was communicated to Smith. On one of his hands were several ulcerated sores, and he was affected with such symptoms as have been before described.
> Case 3. Simon Nicholls was employed in applying dressings to the sore-heels of one of his master's horses, and at the same time milked his master's cows. The cows became affected in consequence, though not until several weeks after he had begun to dress the horse.
> Case 4. A mare, the property of a dairy farmer, began to have sore-heels, which were occasionally washed by the servant men of the farm,—Thomas Virgoe, William Wherret, and William Haynes. They contracted "sores on their hands, followed by inflamed lymphatic glands in the arms and axillae, shiverings succeeded by heat, lassitude and general pains in the limbs ;" and the disease was also communicated to the cows.

From another case in his experience, Jenner thought it highly probable that not only the heels of the horse, but other parts of the body of that animal, were capable of yielding the virus which produces Cow Pox.

> " 'An extensive inflammation of the erysipelatous kind appeared without any cause upon the upper part of the thigh of a sucking colt. . . . The inflammation continued several weeks, and at length terminated in the formation of three or four small abscesses.' Dressings were applied to the colt by those who milked the cows, and ail of them had Cow Pox."

When Woodville discovered Cow Pox, and raised a stock of "vaccine lymph," it was the ordinary "spontaneous " Cow Pox, arising quite independently of any disease of the horse's heels. Jenner nevertheless pronounced the vaccine to be genuine, and abandoned for a while, the horse-grease theory. In An Account of the Origin of the Vaccine Inoculation1 and in his evidence before the Committee of the House of Commons, he omitted any reference whatever to this malady.

Thus when Jenner had published his famous Inquiry, he found that grease, transmitted direct to man, was not protective against Small Pox. In one case, Small Pox was produced by inoculation, and in another, by infection, after an attack of grease. To explain this, Jenner assumed that the virus from the horse's heel must be modified by passage through the cow in order to acquire the peculiar properties which converted it into a protective against Small Pox. Later he abandoned horse grease altogether and advocated "spontaneous" Cow Pox, but still later he reverted to grease, and formally adopted it as the "true life-preserving fluid."2

1 Vide vol. ii., p. 271. 2 p. 393.

Jenner recognised that this vaccinogenic "grease" was not limited to the heels of the horse. The fullest description which he wrote of the disease was the following :—

> " The skin of the horse is subject to an eruptive disease of a vesicular character, which vesicle contains a limpid fluid, showing itself most commonly in the heels. The legs first become oedematous; and then fissures are observed. The skin contiguous to these fissures, when accurately examined, is seen studded with small vesicles surrounded by an areola. These vesicles contain the specific fluid. It is the ill management of the horse in the stable that occasions the malady to appear more frequently in the heel than in other parts; I have detected it connected with a sore on the neck of the horse, and on the thigh of a colt."

According to Baron, Jenner had observed a case of transmission of grease to sheep :—

> " Dr. Jenner, in like manner, had ascertained that the cow was not the only animal capable of receiving the infection of the grease. A sheep that had three lambs, of which two perished, being incommoded by the superabundance of milk, was drawn by a servant who, at the same time, dressed the greasy heels of a horse. Pustules, similar to those of the Vaccine, appeared on the teats of the sheep : the same person who milked the sheep immediately afterwards milked two cows, and communicated the disease to them. From the cows thus infected a servant of the house received the Cow Pox."

Jenner summed up his reasons for attributing Cow Pox to grease as follows :—

> " First. I conceived this was its source, from observing that where the Cow Pox had appeared among the dairies here (unless it could be traced to the introduction of an infected cow or servant) it had been preceded at the farm by a horse diseased in the manner already described, which horse had been attended by some of the milkers."
> Secondly. From its being a popular opinion throughout this great dairy country, and from its being insisted on by those who here attend sick cattle.
> "Thirdly. From the total absence of the disease in those countries, where the men servants are not employed in the dairies.
> " Fourthly. From having observed that morbid matter generated by the horse frequently communicates, in a casual way, a disease to the human subject so like the Cow Pox, that in many cases it would be difficult to make the distinction between one and the other.
> '' Fifthly. From being induced to suppose, from experiments, that some of those who had been thus affected from the horse resisted the Small Pox.
> "Sixthly. From the progress and general appearance of the pustule on the arm of the boy whom I inoculated with matter taken from the hand of a man infected by a horse; and from the similarity to the Cow Pox of the general constitutional symptoms which followed."

Baron has published Jenner's reasons from MS. notes, which contain several important additional details.

> " 1st. From its being the fixed opinion of those who have, been in the habit of attending to cows infected with this disease for a great number of years.
> " 2ndly. From its being a popular opinion in this great dairy-country, and from the cautions the farmer observes when he has a horse with a sore heel.
> " 3rdly. From observing, in almost ever}" instance, that the appearance of the Cow Pox at a farm was preceded by some disease of a horse at the same farm, which produced the discharge of some fluid from the skin.
> "4thly. From having attempted, in vain, to give the Small Pox to the son of a farrier who had had sores and a fever, from dressing a diseased horse.
> "And 5thly. From the peculiar appearance of the pustule, and its disposition to run into an ulcer in the arm of the boy who was inoculated with matter taken from the hand of a man who received the infection from dressing a slight spontaneous sore on a horse's heel."

In testimony of its being a popular opinion, Jenner published a letter on this subject from the Rev. Mr. Moore, of Chalford Hill:1—

> 1 Vide vol. ii., p. 169.
> " In the month of November, 1797, my horse had diseased heels, which was certainly what is termed the grease; and at a short subsequent period my cow was also affected with what a neighbouring farmer (who was conversant with the complaints of cattle) pronounced to be the Cow Pox, which he at the same time observed my servant would be infected with: and this proved to be the case ; for he had eruptions on his hands, face, and many parts of the body, the pustules appearing large, and not much unlike the Small Pox, for which he had been inoculated a year and a half before, and had then a very heavy burthen. The pustules on the face might arise from contact with his hands, as he had a habit of rubbing his forehead, where the sores were the largest and thickest.
> "The boy associated with the farmer's sons during the continuance of the disease, neither of whom had had the Small Pox, but they felt no ill effects whatever. He was not much indisposed, as the disease did not prevent him from following his occupations as usual. No other person attended the horse or milked the cow, but the lad above mentioned. I am firmly of opinion that the disease in the heels of the horse, which was a virulent grease, was the origin of the servant's and the cow's malady."

Jenner remarks :—

> " From the similarity of symptoms, both constitutional and local, between the Cow Pox and the disease received from morbid matter generated by a horse, the common people in this neighbourhood, when infected with this disease, through a strange perversion of terms, frequently called the Cow Pox. Let us suppose then such a malady to appear among some of the servants at a farm, and at the same time that the Cow Pox were to break out among the cattle; and let us suppose too that some of the servants were infected in this way, and that others received the infection from the cows. It would be recorded at the farm, and among the servants themselves, wherever they might afterwards be dispersed, that they had all had the Cow Pox. But it is clear that an individual thus infected from the horse would neither be for a certainty secure himself, nor would he impart security to others, were they inoculated by virus thus generated. He still would be in danger of taking the Small Pox. Yet were this to happen before the nature of the Cow Pox be more maturely considered by the public, my evidence on the subject might be depreciated unjustly."

Jenner also received the following account1 from Mr. Fewster, of Thornbury, "a gentleman perfectly well acquainted with the appearances of the Cow Pox on the human subject:"—

1 Vide vol. ii., p. 170.

" William Morris, aged thirty-two, servant to Mr. Cox of Almonsbury, in this county, applied to me the 2nd of April, 1798. He told me, that four days before he found a stiffness and swelling in both his hands, which were so painful, it was with difficulty he continued his work; that he had been seized with pain in his head, small of the back, and limbs, and with frequent chilly fits succeeded by fever. On examination I found him still affected with these symptoms, and that there was a great prostration of strength. Many parts of his hands on the inside were chapped, and on the middle joint of the thumb of the right hand there was a small phagedenic ulcer, about the size of a large pea, discharging an ichorous fluid. On the middle finger of the same hand there was another ulcer of a similar kind. These sores were of a circular form, and he described their first appearance as being somewhat like blisters arising from a burn. He complained of excessive pain, which extended up his arm into the axilla. These symptoms and appearances of the sores were so exactly like the Cow Pox, that I pronounced he had taken the distemper from milking cows. He assured me he had not milked a cow for more than half a year, and that his master's cows had nothing the matter with them. I then asked him if his master had a greasy horse ? which he answered in the affirmative ; and further said, that he had constantly dressed him twice a day for the last three weeks or more, and remarked that the smell of his hands was much like that of the horse's heels. On the 5 th of April, I again saw him, and found him still complaining of pain in both his hands, nor were his febrile symptoms at all relieved. The ulcers had now spread to the size of a seven-shilling1 gold coin, and another ulcer, which I had not noticed before, appeared on the first joint of the forefinger of the left hand, equally painful with that on the right. I ordered him to bathe his hands in warm bran and water, applied escharotics to the ulcers, and wrapped his hands up in a soft cataplasm. The next day he was much relieved, and in something more than a fortnight got well. He lost his nails from the thumb and fingers that were ulcerated."

Mr. Tanner was the first to succeed in experimentally transmitting grease to the cow by inoculating some of the liquid matter from the heel of a horse. The result was the production of a " vaccinal vesicle," and he wrote :—

> " From handling the cow's teats, I became infected myself, and had two pustules on my hand, which brought on inflammation and made me unwell for several days. The matter from the cow and from my own hand proved efficacious in infecting both human subjects and cattle."

Jenner received some of Tanner's equine virus while he was in London, in April 1800, and some of it, he passed on to Mr. Wachsel of the Small Pox Hospital.

In the same month some observations tending to confirm Jenner's opinion were made by Mr. Lupton, a surgeon of Thame, Oxfordshire, which were communicated to Jenner by Sir Christopher Pegge, and published in the Medical and Physical Journal.
In the year 1801, Dr. Loy published his experiments in a work entitled Some Observations on the Origin of Cow Pox.1 Coleman, Woodville, and Simmons had negative results when they experimented on cows, with grease, but Dr. John Loy met with very different experience. Mr. Loy, surgeon at Pickering, had undertaken experiments from having met with the following cases:—

1 Vide vol. ii., p. 2-9.

> " I. A farrier applied to him with an eruption on his hands, composed of distinct pustules, containing a thin fluid, and surrounded by an inflamed ring. The vesicle had an appearance similar to that arising from a burn. They were all regularly circumscribed, and a small dark speck could be discovered in the middle of each. The patient had been dressing a horse affected with the grease. He had had Small Pox.
> "II. A young man, a butcher, at Middleton, near Pickering, was affected with painful sores on both his hands, particularly about the roots of the nails. These sores in a few days became inflamed, and a vesicle formed upon each. Soon after the appearance of the vesicles, a number of red painful lines, which appeared to be inflamed lymphatics extended from the pustules to the arm-pit, where a tumor formed; he had also a pustule, of the same appearance as those on his hands, upon one eyebrow, which, he said, had been affected with an itching, inducing him frequently to scratch it; and the pustule had no doubt been communicated in that manner from his fingers. He had a considerable degree of fever, which continued obstinate till the absorption from the pustules was prevented by destroying them with caustic, when the tumor in the axilla also dispersed. This patient, like the former, had been for some time employed in applying remedies to the heels of a horse affected with the grease, and was continuing to do so at the time he begun to be indisposed. He had never undergone the Small Pox."

Mr. Loy, being curious to ascertain whether this disease could be communicated by inoculation, took a quantity of matter from the pustules of this patient and inserted it into the arm of his brother, with the following results :—

> " In a few days, some degree of inflammation appeared, and on the eighth day, a vesicle formed; my patient had now some slight feverish symptoms, which continued a day or two.
> " This disease had exactly the appearances of the genuine Cow Pox, and I intended to have tried the effect of the Small Pox virus, had not the fears of the boy's parents prevented me."

At the same time that Mr. Loy performed this experiment, Dr. John Loy inoculated the udder of a cow with matter from the pustule of the same patient. When the animal was inspected on the ninth day, there was a vesicle with a "rose-coloured rim." Matter was taken and inserted into the arm of a child. The inflammation, vesication, and scabbing which followed corresponded with Cow Pox. On the sixth day of the disease, the child was inoculated with Small Pox. The wound "seemed to be rather inflamed on the third day, but in a few days more it healed."

Dr. Loy then inoculated another child, with matter taken direct from Mr. Loy's patient. The results were similar to the effects of Cow Pox, and subsequent inoculation of Small Pox produced no effect. The next experiment was with another case of grease. A cow was inoculated, and in a few days, a vesicle formed containing a large quantity of watery fluid, and of a purple tinge. A quantity of the limpid water was inserted into the arm of a child. A vesicle formed on the ninth day, and the same day, the child was inoculated with Small Pox without effect.

Dr. John Loy then inoculated a child direct from a horse suffering from grease.

> " On the third day, a small degree of inflammation surrounded the wound. On the fourth, the inoculated place was much elevated, and a vesicle, of a purple colour, was formed on the fifth day : on the sixth and seventh, the vesicle increased, and the inflammation extended, and became of a deeper colour; on the same day, a chilliness came on, attended with nausea and some vomiting. These were soon succeeded by increased heat, pain in the head, and a frequency of breathing; the pulse was very frequent, and the tongue was covered with a white crust. When in bed, the child was much disposed to sweat. By the use of some medicines, and exposure to cool air, the feverish symptoms soon abated, and disappeared entirely on the ninth day. On the sixth day, Small Pox matter was inserted into the same arm in which the matter of Grease had been placed, but at a considerable distance from it. On the fourth and fifth days of the Small Pox inoculation, some redness appeared about the wound, and on the sixth a small vesicle. The inflammation now decreased, and on the ninth day, the vesicle was converted into a scab."

On the sixth day of the inoculation, four other children were inoculated with matter from this child. On the tenth day, an extensive erysipelatous efflorescence surrounded the vesicles. On the same day, they were all inoculated for the Small Pox, in the arms free from the former inoculation. Nothing appeared except a very small degree of inflammation. It is not stated whether the lymph stock was carried on.

PEDIGREE OF THE FIRST STOCK OF DIRECT EQUINE LYMPH.
Horse
A Child
Five Children

Loy had made a number of experiments with grease, but only in certain cases did he succeed in getting positive results, for which he gave the following reason :—

> " This fact induces me to suspect, that two kinds of Grease exist, differing from each other in the power of giving disease to the human or brute animal ; and there is another circumstance which renders this supposition probable. The horses that communicated the infection to their dressers were affected with a general, as well as a topical disease. The animals, at the commencement of their disease, were evidently in a feverish state, from which they were relieved as soon as the complaint appeared at their heels, and an eruption upon the skin. The horse, too, from whom the infectious matter was procured for inoculation, had a considerable indisposition, previous to the disease at his heels, which was attended, as in the others, with an eruption over the greatest part of his body; but those that did not communicate the disease at all, had a local affection only. From this, perhaps, may be explained, the want of success attending the experiments of the gentlemen I have mentioned."

Loy also observed that the grease appeared to act with greater mildness after having been cultivated on the cow, or the human subject. Thus after direct inoculation from the horse, a purple tinge was observed, but this did not appear with lymph which had been passed either through the medium of the cow or the human subject.
With regard to the application of the variolous test, all Loy's experiments were deprived of any value. No conclusions could be drawn when the inoculation was performed at or near the height of the disease, which had been produced by insertion of the virus of grease. Loy ought to have been fully aware that under such circumstances, inoculation would prove abortive.

Jenner was the first to perform arm-to-arm indirect, and Loy was the first to perform arm-to-arm direct equination.

Jenner sent a copy of Loy's work to the Duke of Clarence with a letter, in which he made the following remarks :—

> " In obedience to the wish your Royal Highness expressed to me at Lord Grantley's, I have done myself the honour of sending you Dr. Loy's pamphlet on the Origin of the Cow Pox, which decisively proves my early assertions upon that subject. This discovery is the more curious and interesting as it places in a new point of view the traditionary account handed down to us by the Arabian physicians that the Small Pox was originally derived from the camel. The whole opens to the physiologist a new field of inquiry, and I sincerely hope it may be so cultivated that human nature may reap from it the most essential benefit."

Dr. Loy also corresponded with Jenner on this subject.

> > Dr. Loy to Dr. Jenner.

> "Sir,—I have not yet had an opportunity of making any further experiments respecting the origin of the Cow Pox, on account of the disease of grease having been of late remarkably rare in this country. From the evidence, however, I have had of the truth of your opinion, and from some observations which have been made on my experiments by my worthy preceptor, Dr. Duncan, of Edinburgh, I consider myself in some degree called upon to pay more attention to this curious subject, and you may, Sir, be assured that you shall be informed of my success.
> " I have the satisfaction to mention that the subject inoculated with the grease matter on Experiment VI. has withstood the action of the Small Pox, by way of repeated exposure to the natural disease. Several of those also who were inoculated with vaccine virus, generated by inoculation with the equine, have been exposed more than once to the natural infection of the Small Pox, but without the least effect. Dr. Duncan seems to conjecture that the persons on whom the experiments were performed might have previously had the small Pox; but any foundation for such a supposition is perfectly groundless. Most of the persons who were subjected to the experiments had never been within several miles of the Small Pox till inoculated. And that the small Pox matter I made use of was good is proved by the same virus giving readily the disease to others.
> " There is not the least doubt but the experiments will remain successful; and that they were fairly performed many respectable gentlemen in this neighbourhood can testify. One gentleman at my request saw me inoculate one of his cows from the greased heels of his horse, with a lancet which he himself supplied me at the time of experiment. This trial was successful. . . .
> " Give me, Sir, the honour to subscribe myself,
> "Your faithful friend and servant,
> " John Glover Loy.

> " Whitby, December 26th, 1802."

Experiments with grease were also made, about this time, on the Continent. Dr. De Carro appears to have been the first to communicate to Jenner the result of some experiments conducted by Sacco.

"If you have felt so much pleasure in hearing that your discovery is known and practised in India, I hope that my late intelligence of the true Cow Pox, produced at Milan with the giardoni on Dr. Sacco's own horse and that of one of his neighbours, has not been less agreeable to you."

And in a reply to his letter Jenner makes some observations on this subject.

> Dr. Jenner to Dr. De Carro.
> " March 28th, 1803.
> "Since the commencement of our correspondence, great as my satisfaction has been in the perusal of your letters, I do not recollect when you have favoured me with one that has afforded me pleasure equal to the last. The regret I have experienced, at finding that every endeavour to send the vaccine virus to India in perfection, again and again failed, is scarcely to be described to you; judge, then, what pleasure you convey in assuring me that my wishes are accomplished. I am confident that had not the opponents, in this country, to my ideas of the origin of the disease been so absurdly clamorous (particularly the par nobile fratrum) the Asiatics would long since have enjoyed the blessings of vaccination, and many a victim been rescued from an untimely grave. The decisive experiments of Dr. Loy on this subject have silenced the tongue of these gentlemen for ever.
> " I am happy to see this interesting work translated by you, and hope it will travel the world over.
> " It is very extraordinary, but certainly a fact, that the plate which I gave in my first publication of the equine pustule (although its origin was detailed) was by almost every reader considered as the vaccine. There are probably some varieties in the pustules which arise among horses. You will observe, by a reference to my publication, that the virus in the instance I now allude to, was so very active that it infected every person who dressed the horse.
> " I am happy to find an opinion taken up by me, and mentioned in my first publication, has so able a supporter as yourself. I thought it highly probable that the Small Pox might be a malignant variety of the Cow Pox. But this idea was scouted by my countrymen, particularly P. and W. . . ."

In a subsequent letter, De Carro gave an account of some important experiments by Dr. La Font.

De Carro to Dr. Jenner.

> "Vienna, 2ist June, 1803.
> "My dear Sir,—My friend Dr. Marcet wrote to me lately that the accounts I have sent to you of Dr. Sacco's experiments have afforded you great satisfaction. The motive which induces me to write to you to-day is another confirmation of your theory which has taken place in a country where you scarcely expect it from, the more so that it is accompanied with veterinary observations which appear to me very nice and curious.
> "Monsieur La Font, a French physician established at Salonica in Macedonia, has been one of the most active vaccinators I know on the continent . . . Some time afterwards, I sent him a translation of Dr. Loy's experiments, and desired him to make as many veterinary observations and experiments as he could. He has some reason to suppose that the Cow Pox reigns in that country, according to the report of several Albanese peasants. As to the grease (which he calls javart), he says that the farriers at Salonica know it very well. Dr. La Font began his experiments with the kind of grease which the Macedonian farriers call the variolous. He found a horse which had been attacked with feverish symptoms, that ceased as soon as the eruption appeared. The fore legs were much swelled; the left had four ulcers, one upon the heel, a second some inches higher, a third on the articulation, a fourth near the breast. The eruption on the legs was, he says, very like the Small Pox, but none was to be seen on the other parts of the body. He took matter from the upper ulcer, which was of twelve days' standing. The matter was limpid, but a little yellowish and filamentous (thready); first, a cow was submitted to this inoculation, but without success ; secondly, a girl twelve years old, without effect; but this girl had been vaccinated some months before without success, and was suspected to have had the Small Pox; thirdly, two boys, one six, the other five, years old, were inoculated with the same equine matter ; and in both, a pustule appeared, which followed the regular course of a vaccine pustule. The colour was less white, and more purple than usual. Those two children had a pretty strong fever, for which some cooling medicines were administered. Those inoculated with matter from them underwent the disease in its usual mild way.
> "These particulars, I hope, will silence all those who still doubt of the truth of your doctrine. These observations enhance the merit of your discovery. The means of making it were everywhere ; yet nobody before you had the least idea of that singular connection between the grease, the Cow Pox, and the Small Pox."

On March 25th, 1803, Sacco communicated to Jenner the details of his experiments.

> "I have for a long time been making experiments with grease in order to confirm your opinion of the origin of vaccine. Until the beginning of this year, I have had only negative results. Studying Mr. Loy's little book encouraged me to make another attempt. In the winter of this year grease could not have been more common than it was, in consequence of the quantity of water which there was and the mud which resulted on the roads ; thus nearly all the horses suffered from grease, my servant was attacked by it on both forearms, having five vesicles from dressing one of my horses suffering from grease. He only informed me of it when the vesicles were beginning to dry up. This encouraged me to continue my experiments. I inoculated several children and several cows with the virus which came from grease at different stages, but always without effect. A coachman came to the hospital to be examined with an eruption which he had on his hands; it was at once recognised that it was vaccine taken while treating horses, which in fact he had dressed. He was taken to the foundling hospital, where some inoculations were made. He came to me the same day, and I made nine inoculations on as many children, and I inoculated the teat of a cow as well. Three of these children had an eruption exactly like Cow Pox. Nothing happened in the cow. I made other inoculations with matter taken from these children, and I have already reached the fourth remove, which reproduces itself with the same effect as vaccine. I have already inoculated several of these individuals with Small Pox, but without any effect. It is therefore very certain that the grease is the cause of Cow Pox, and the name may at once be changed to equine or into anything which you think better. I have also at last obtained, with the virus of grease inoculated with six more children, two vesicles exactly like those of vaccine. I am construing my observations. Everything points to the conclusion that we shall procure from grease a virus for protection against Small Pox without the intermedium of the cow.
> " I hope that this new proof will remove the doubts which still existed about the origin of Cow Pox. I will publish the results of these experiments in a work on vaccination, to which I will add a coloured plate of grease."

Jenner replied to Sacco, expressing his confidence in his original theory.

> "Accept my best acknowledgments for your very kind attention. I am extremely gratified by your goodness in sending me your pamphlet on Vaccine Inoculation, your obliging letter, and above all the virus from the plains of Lombardy. I am confident that wherever the horse and the cow are domesticated together, and the same human being that attends the one, under a peculiar malady of the foot, milks the cow also, that there the disease called the Cow. Pox may arise."

In Paris, according to Baron, equination was practised in 1812.

> " A coachman who had not had Small Pox, and who dressed a horse affected with the grease, had a crop of pustules on his hands, which resembled the vaccine. Two children were inoculated from these pustules, and the genuine vaccine was excited in both : from this stock many successive inoculations were effected, all possessing the proper character. A similar series of inoculations took place from another infant who was infected from one of the scabs taken from the pustules on the hand of the coachman."

In spite of these results the theory was still discredited in London, and Jenner wrote to Moore, July 23rd, 1813, giving information of a fresh stock of equine virus which he had been using for months.

> " In one of your letters you seemed not perfectly satisfied that the fact respecting the origin of the vaccine was clearly made out. For my part, I should think that Loy's experiments, independently of my own observations, were sufficient to establish it, to say nothing of Sacco's and others' on the Continent. However, I have now fresh evidence, partly foreign and partly domestic. The latter comes from a Mr. Melon, a surgeon of repute at Lichfield. He has sent me some of his equine virus, which I have teen using from arm to arm for these two months past, without observing the smallest deviation in the progress and appearance of the pustules from those produced by the vaccine. I have at length found the French document I formerly alluded to, which, with Melon's, shall be sent to you in the course of the ensuing week."

Jenner wrote, again, on the same subject, August 1st, 1813.

> To James Moore, Esq.
> " Dear Moore,—My friend and neighbour, Mr. Hicks, will deliver to you the promised papers respecting equine virus. I have been constantly equinating for some months, and perceive not the smallest difference between the pustules thus produced and the vaccine. Both are alike, because they come from the same source."

And again, in a letter, dated October 27th, 1813 :—

> " I am sorry you have not succeeded in infecting a cow. I have told you before that the matter which flows from the fissures in the heel will do nothing. It is contained in vesicles on the edges and the surrounding skin. Did I ever inform you of the curious result of vaccinating carters? These people from their youth up have the care of the horses used for ploughing our corn lands. Great numbers of them in the course of my practice here have come to me from the hills to be vaccinated; but the average number which resisted has been one half. On inquiry, many of them have recollected having sores on their hands and fingers from dressing horses affected with sore heels, and being so ill as to be disabled from following their work; and on several of their hands, I have found the cicatrix as perfect and as characteristically marked as if it had arisen from my own vaccination."

Jenner now appears to have almost, if not entirely, abandoned vaccination for equination. On the 1st of April, 1817, he made the following memorandum:—

> " Rise and progress of the equine matter from the farm of Allen, at Wansell. From a horse to Allen; from Allen to two or three of his milch cows ; from the cows to James Cole, a young man who milked at the farm ; from James Cole to John Powell, by inoculation from a vesicle on the hand of Cole; and to Anne Powell, an infant; from Powell to Samuel Rudder; from Rudder to Sophia Orpin, and to Henry Martin; from H. Martin to Elizabeth Martin. All this went on with perfect regularity for eight months, when it became intermixed with other matter, so that no journal was kept afterwards. Proof was obtained of the patients being duly protected."

And among other entries to a similar effect, there was, on the 17th of May, the following:—

> " Took matter from Jane King (equine direct), for the National Vaccine Establishment. The pustules beautifully correct."

This stock of equine lymph was widely diffused. Baron and many medical friends received supplies of it, and it was also introduced into Scotland.

Baron adopted equination, and made notes of cases of grease. .

> " It happened to me to see one case of this kind in the autumn of the year 1817. A young man in this neighbourhood, who had dressed a horse with the grease, had not less than fifty pustules on his hand and wrists. They exhibited the true character of the Variolae Vaccinae when taken in the casual way. The pustules were too far advanced to permit of any experiments being made with virus taken from them. I cannot refrain from remarking in this place, that as the disease, whether caught from the cow or the horse, is much more severe than when communicated by inoculation, so it likewise differs from the last in being sometimes what may be truly called an eruptive disease. Besides the case just specified, I know of instances where the disease, when it has been caught from cows in the dairy, has produced pustules more extensively diffused over the body than in the case above mentioned."

In the following year, Baron sent some fresh equine virus to Jenner. It was obtained from the hands of a boy who had been infected directly from a horse. The disease assumed a pustular form, and extended over both arms.

Jenner acknowledged the receipt of Baron's virus in the following letter :—

"April 25th, 1818.
"Yesterday H. Shrapnell brought me the equine virus and your drawing, which conveys so good an idea of the disease that no one who has seen it can doubt that the vesicles contain the true and genuine life-preserving fluid. I have inserted some of it into a child's arm ; but I shall be vexed if you and some of your young men at the Infirmary have not done the same with the fluid fresh from the hand."

In 1818, Kahlert,1 on the Continent, confirmed the experiments made by Loy and Sacco.

> " In the month of May 1818, one of my friends remarked to me that two horses which he had just bought were not in their usual state of health ; that they quickly became fatigued, that their hind legs were stiff, and that they even went lame, and in fact he thought they were suffering from javart (mauke).
> " These two horses were of the ordinary breed of the country (Bohemia), black, six years old, well nourished, and well cared for, but according to the groom they had for some time lost their spirit and appetite. ... I at once noticed that the joint of the foot was swollen, that moisture exuded from it, and that the posterior part of the pastern was still slightly red and swollen, and hotter than the neighbouring parts. At the slightest touch, the animal showed signs of pain ; the hair was stuck together, and a clear yellowish fluid with a peculiar odour escaped. ... I was not slow in recognising the true equine preservative. I collected the fluid on a lancet to inoculate cows and children."
> The experiments on cows succeeded; children were inoculated from the vesicles which resulted, and a lymph stock was started which was widely used.

1. L'Almanach de Carlsbad. Du javant ftrescrvatif trouve en Boheme. 1833. (Quoted by Auzias-Turenne.)

In an appendix to the second volume of Jenner's Biography, published in 1837, Baron made the following
remark :—

> " I take this opportunity of expressing my regret that I have employed the word grease in alluding to the disease in the horse. Variolœ; Equinœ is the proper designation. It has no necessary connexion with the grease, though the disorders frequently co-exist. This circumstance at first misled Dr. Jenner and it has caused much misapprehension and confusion."

In 1840, Ceely remarked that there were farmers and others who had good reason for believing in the origin of Cow Pox from the equine vesicle, which he regarded as eczema impetiginodes.

Jenner's theory of the origin of Cow Pox has been discouraged, and completely replaced by the theory of Cow Small Pox, advocated so strongly by Baron, and supported by an erroneous interpretation of Ceely's and Badcock's variolation experiments; and thus the "Cow Pox" and the "grease" of the farmers were no longer of interest, while the hypothetical Cow Small Pox, which could never be discovered, has been credited with having become extinct, since the days of Jenner. At the present day the derivation of "vaccine lymph" from a disease of the horse is, almost, if not entirely, unknown to medical practitioners, and certainly vaccinogenic "grease" in this country is not differentiated by practical veterinarians of the present day, from the various diseases which it simulates. Like actinomycosis, it has been lost sight of under a variety of appellations. I would draw the attention of veterinarians to this, by giving a detailed account of the researches carried out by veterinary surgeons in France.
First Outbreak at Toulouse.

In 1860, the horses at Rieumes, near Toulouse, were attacked by an epizoőtic malady. In less than three weeks, there were more than one hundred cases. According to the veterinary surgeon, M. Savrans, the animals suffered from slight fever, rapidly followed by local symptoms, the most marked of which were swelling of the hocks, and an eruption of small pustules on the surface of the swollen parts, which were at the same time hot and painful. After three to five days there was a discharge from the pastern, which continued for eight to ten days, during which the inflammation gradually diminished. The pustules dried up, and in about a fortnight the crusts with patches of hair fell off, leaving more or less marked scars.

The eruption appeared at the same time on different parts of the body, especially on the nostrils, lips, buttocks, and vulva. Savrans believed that the mares taken' to the breeding establishment at Rieumes had been infected from the cords which had been used in tying up other affected animals and had become thereby infected with the virus of this disease.

One of the mares was taken by the owner, M. Corail, to the veterinary school, to be examined by M. Lafosse. About eight days after this visit, significant symptoms appeared: loss of appetite, lameness, stiffness of both pastern joints, and a hot, painful swelling of the left pastern joint.

The hair was staring, and there were vesicles on the skin, from which a liquid exuded having an ammoniacal odour, but less foetid than the secretion in eaux mix jambes.

M. Lafosse regarded it as a case of acute grease, and this led him to inoculate a cow. This experiment, made on the 25th of April, a week after the eruption had first appeared on the mare, was completely successful. On the teats of the inoculated cow, at every puncture, there were large, flat, firm, round, umbilicated vesicles. They had all the characters of inoculated Cow Pox. Another cow inoculated with liquid from this first remove, manifested typical vesicles, which, transmitted to a child and to a horse, gave rise in both cases to a very fine "vaccinal " eruption. A child inoculated from the vesicle of this horse had also "vaccine vesicles." On making a comparative inoculation with current vaccine lymph on the same subject, the vesicles were found to be larger, finer, and slower in their development. When M. Lafosse detected the disseminated eruption on various parts of the body, especially around the lips and nostrils, he recognised that the disease was not an ordinary attack of grease.

The occurrences at Rieumes and Toulouse were communicated to the Academy of Medicine, in 1862, by M. Bousquet; and M. Renault observed that the original error in diagnosis, made after a cursory examination, by M. Lafosse, added greatly to the interest of the inoculation experiment, because it might explain the difference in the results obtained up to the present time by medical men and veterinary surgeons who since Jenner had inoculated the grease. Renault said:—" It may be possible that the few experimenters who assert that they have seen Cow Pox result, under their hands and eyes, from accidental or experimental inoculation of the matter of the grease, were in reality dealing with the vesicular malady of Toulouse, while the much larger number of them who obtained no effect from their inoculations must have employed the discharge from the true grease, which was formerly so common."

Renault added :—" The occurrence at Toulouse is of great importance in drawing attention to this subject, which will lead to further discussion. It will teach veterinary surgeons that there is an affection, principally manifested on the horse's heels, which appears up to this time to be readily mistaken for the grease, from which, however, it can be easily distinguished by attentive examination. It will teach them how important it is to study at the same time the characters of this disease, and the effect of inoculation."
Outbreak at Alfort.

In 1863, the subject of Horse Pox again received great attention in France. A student named Amyot dressed a horse on which an operation had been performed. The leg which had been operated on (right hind leg) became the seat of a very confluent eruption of Horse Pox, which was followed by such an abundant flow of serosity that at first the nature of the affection was mistaken, and it was thought to be a complication of eaux aux jambes. Amyot had a wound on the dorsal aspect of the first interphalangeal joint of the little finger of his right hand ; in spite of this, he continued to dress the horse entrusted to his care. The sore on his finger was the seat of an accidental inoculation with the virus which flowed in such great abundance from the horse's leg. The wound was made on the 3rd of August, and the next day it was swollen and rather painful. On the 5th, Amyot suffered from malaise and great weakness, on the 6th, 7th, and 8th, vesicles appeared successively on the fingers of his left hand, on his forehead, on a level with the root of his nose, and between the two eyebrows. On the 9th, these vesicles were fully developed ; those of the fingers consisted of very large epidermic bullae on a bluish-red base. On opening them, a perfectly limpid fluid escaped in such abundance that small test-tubes might have been filled with it. The vesicle on the forehead was surrounded by a bluish-red areola, within which the epidermis of a leaden-grey hue was raised and had a slight central depression. The liquid which flowed from it when it was opened, and which continued to ooze, was also very abundant and of a deep citrine colour.

The vesicles which had developed on the dorsal side of Amyot's fingers were extremely painful. The incessant shooting pains, of which they were the seat, prevented him from getting any rest for three days. On the 10th, inflammation of the lymphatics followed ; both arms were swollen and very painful, with red lines indicating the course of the lymphatic vessels. The glands of the axillae were also enlarged.

The lymphatic glands behind the jaws were also swollen and painful. Amyot's chief sufferings were occasioned by the intense local pain caused by the vesicles on the fingers, and by the inflammation of the lymphatic vessels and glands, and they continued in this state up to the 18th of August. It was only at the end of the month that the vesicles were completely cicatrized.

Bouley felt very great anxiety in the presence of the grave symptoms which accompanied the eruption, so closely did these symptoms resemble in their mode of manifestation and their intensity the effects of an inoculation much more alarming than those of the virus of grease. The eruption on the forehead was, especially, a cause of great uneasiness, because glanders manifests itself in a similar way. But when, on the morning of the 9th, Amyot showed Bouley the pustules on his fingers and on his forehead fully developed, the latter was completely reassured, for he recognised without any hesitation, that they had the characters of "vaccine vesicles." This diagnosis was supported by Drs. Marchant, Auzias-Turenne, Bayer, Depaul, and Blot, who successively saw Amyot on the same day, and had only one opinion as to the nature of his malady. Amyot evidently had inoculated himself with the grease which Jenner and Loy had seen and described. They were of opinion, that Amyot's illness had been much more severe and had lasted for a longer time, than in others who had been victims, as he had been, of an accidental inoculation with Jennerian grease, or Loy's disease.

To complete the history of Amyot, and to demonstrate that the malady which he had contracted, while attending to the horse, was really Horse Pox, Bouley, on the 12th of August, inoculated the liquid taken from the vesicles on his fingers, in the scrotal region of a steer, and produced "magnificent Cow Pox," which, when inoculated on a child, was followed by a very fine vaccinal eruption.

This case of Amyot, so well circumstantiated and studied in all its details, was fresh evidence in favour of Loy's opinion that the equine virus is gifted with greater energy than that of the cow, and produces a much more marked effect on the human subject.

The outbreak at Alfort enabled exhaustive experiments to be made, by which it was definitely established that Horse Pox is never infectious, but, like Cow Pox, is transmitted solely by contact.

Not having been able to get any practical information on the subject of Horse Pox1 in this country, I made it one of my principal objects during a visit to France to inquire into and, if possible, practically study this malady. It was, therefore, with great interest that I heard that Professor Peuch, of Toulouse, had not only investigated outbreaks of this disease, but also was in the possession of drawings illustrating its different manifestations. Professor Peuch described to me his experience, giving me the details of his observations, and allowed me to have copies made of his valuable drawings. I cannot, do full justice to M. Peuch's admirable researches unless I give the full details in his own words.

1 The term equine, as a substitute for vaccine, was first employed by Sacco, in a letter to Jenner, in 1803 (p. 389); and both equine, and Horse Pox were, independently, proposed by Mr. Brown of Musselburgh. Vide An inquiry into the anti-variolous power of Vaccination, p. 63. 1809.
Second Outbreak at Toulouse.

M. C. Baillet, Director of the National Veterinary School of Toulouse, having been informed that a contagious malady had developed in the mares which had been served by the stallions at the breeding establishment at Rieumes belongano- to M. Mazeres, delegated M. Peuch to inspect these animals in order to ascertain the nature of the illness with which they were affected, its mode of propagation, and the means of arresting it.

With this object in view, M. Peuch visited, on the 10th and 11th of May, 1880, at Berat, Rieumes, and Labastide-Clermont, several mares which had been served by the stallions of M. Mazeres, and also the stallions themselves.

M. Peuch reported the result of his investigations in the Revue Vetdrinaire de Toulouse, the following July.

> "At Berat, I examined, in the presence of my colleague, M. Averadere, three mares already attacked, and these I will speak of as Nos. I, 2, and 3.
> " No. 1. A mare (Isabel) eight years old, had been served on 25th, 27th, and 30th of April. This animal showed on the lips of the vulva a sort of cicatricial mark of a whitish colour, of an elongated form, with edges scalloped and slightly in relief, covered here and there by a few brownish crusts, and showing elsewhere, and principally in the neighbourhood of the folds of the vulval orifice, small reddish superficial ulcers. Towards the upper commissure of the vulva there were several round or oval scars, the size of a large lentil ; some obviously depressed in the centre, which was covered by a small crust; others were circular like little leprous marks. I did not observe any pustule, or a trace of one on other parts of the body. There was not any lesion on the nose, in the nostrils, on the internal surface of the lips, or in the mouth. This mare, who was very spirited, retained her full vigour, and it did not appear as if the eruption had weakened her in any way.
> "No. 2. A black mare, eight years old, had been served on the 26th and 28th of April. Several ulcerated, reddish, circular sores, surrounded by a cicatricial zone, existed on the lips of the vulva, notably towards their free edge. The majority had attained the size of a twenty-centime piece. There was not any eruption in the nostrils, the mouth, or the internal surface of the lips ; no modification of the general condition ; no difficulty in locomotion.
> " No. 3. A bay mare, eight years old, had been served the 23rd, 25th, 27th, and 30th of April. At the circumference of the vulva there were very numerous white, lenticular, slightly elevated, isolated, or confluent marks, extending over the perinaeum. These marks, which were only dried pustules, showed at their centre, which was appreciably depressed, a blackish dry and adherent crust, under which the skin had a bright red colour when the central crust was raised. I also established the existence of dried pustules, showing the same characters as the preceding, on the under surface of the tail, where they were disseminated in considerable numbers. I scraped off these crusts with the nail and preserved them. On the lower part of the left flank a discoid vesicle was discovered with a diameter of about a centimetre. On raising the crust which covered it, a sero-sanguinolent liquid oozed from the exposed surface. There was nothing to remark on other parts of the body. The general state was most satisfactory ; there was no lameness;
> " Such were the symptoms which I observed at Berat on the 10th of May. To what disease were they attributable? Were they to be considered as indications of the malady sometimes known as syphilis, or the venereal disease of the horse (maladie venerienne du cheval) ? This is a very important question in the interests of the breeder and the owner of stallions, which cannot be too carefully investigated, for when an eruptive disease appears after coition, in a locality abounding with breeding mares, the alarmed breeder thinks it must be a syphilitic malady, and it therefore remains for the veterinary surgeon to explain the true nature of the illness. But the symptoms which I have just described belonged obviously to an eruptive affection in the stage of desiccation, and even cicatrisation in No. I ; so that the diagnosis, the consequences of which are so important, must offer serious difficulties, especially to the practitioner who has not had the opportunity of observing similar cases. I do not hesitate to remark that it appears very difficult, not to say impossible, to recognise with certainty the nature of the eruption in question, when it is seen in a subject for the first time, in the stage of desquamation.
> " But such was not the case in this outbreak.
> " Having several times had the opportunity of examining mares with a vesicular eruption around the vulva, after coition (an eruption which I had been able to follow from its first appearance to complete cicatrisation, and which was shown by inoculation of the cow to be Horse Pox), I found myself in a favourable position to appreciate, at their true value, the symptoms which I had discovered in the above-mentioned mares. Recalling to mind what I had observed on several occasions, I asserted that it was a case of the disease which M. Bouley, in 1863, called Horse Pox, and which Auzias-Turenne proposed to distinguish by the name pustular grease (grease pustuleux), a malady essentially different from la maladie du coit, or dourine, but, like it, propagated during coition.
> "After this inspection at Berat I proceeded to Rieumes, to the same establishment where, twenty years previously, a sort of enzooty had appeared, which has been described in the historical records of Vaccination, and which gave M. Lafosse the opportunity of rediscovering the vaccinogenic disease of the horse, which was considered extinct, since the days of Jenner, or at any rate the greatest confusion existed as regards diagnosis. I there inspected eleven stallions, six horses, and five asses. All, with the exception of the breeding stallion Touche-a-tout, which at other times was readily excited, served mares in my presence, so that I was able to examine the penis of each before the act of coition.
> " On one ass (Aramis) I observed on the right side of the penis several vesicles, scattered about from the base of the free part to the head of this organ. These vesicles, which were flattened and circular, varied in diameter from the size of a lentil, to that of a twenty-centime piece ; they had at their periphery, which was slightly in relief, a greyish colour; at their centre, where the epidermis had been destroyed, they presented a bright rose colour and a finely granular appearance. All these vesicles were distinct from each other, and there was no infiltration or swelling of the penis. A little above the circular swelling which constitutes the base of the free part of the penis, a little dried vesicle was found with a central brownish crust. On another ass, called Mexico, I saw, on one aspect of the penis, a little whitish spot, circular but not in relief, on the skin, which appeared to me to be the scar of a grease vesicle. Whatever this might have been, this animal had on the external wing of the left nostril, a small pustule, which, nevertheless, showed well the characters of the vesicles of Cow Pox, or of 'grease.' I did not meet with any trace of eruption on other parts of the body, but it is not impossible that some dried vesicles may have escaped my notice; for it can be readily imagined how easy it is to overlook them in asses, with so long a coat. On the other three breeding asses I could not detect any vesicle or trace of vesicle either on the penis, the nose, around or within the lips, in the hollow of the heel, or, indeed in any part of the body, which I examined as well as I was able to considering the extreme liveliness of these animals, which fidgeted without intermission. I can say the same of the six stallions, which I examined with the greatest care without being able to find any trace of the eruptive disease, observed on the three mares and the two asses.
> " But I can assert that all these stallions had coition with great ardour and without any sign of weakness, that their gait, their proud and confident bearing, their repeated and sonorous neighings, all, in fact, including their impatience, which rendered examination difficult, testified to their extreme energy and to their somewhat exuberant health. What a contrast to the maladie du coit! Moreover, amongst the mares which had already been served by the Rieumes stallions, and were presented to them again, I remarked two which I will designate as Nos. 4 and 5, and over which I think it useful to pause for a few moments.
> " No. 4. Very old bay mare. This animal showed traces of an eruption of Horse Pox on the circumference of the vulva : here and there little dried and flattened vesicles were to be seen passing on to cicatrisation. I should mention that as the proprietor of this mare had not been alarmed by the eruption, no treatment had been employed, and the cicatrisation took place naturally and in the ordinary way.
> "No. 5. A white mare, eighteen years old, was served on the 22nd and 26th of April. On the lips of the vulva there were some vesicles of grease passing on to desiccation. In addition on the inside of the lower lip, near to the attached border, there was found, on the right side, a very fine vesicle of a pale yellow colour, of an ellipsoidal form, and of the size of a pea, not flattened or umbilicated, but well rounded, projecting, smooth, and of a pearly appearance. By the side of this vesicle or bulla a second was noticed, smaller, and not exceeding a hemp seed in volume, and with the summit slightly eroded. I may say, in passing, that an inexperienced observer might have considered these vesicles to indicate aphthous stomatitis; but if we recall the remarkable observations contributed by H. Bouley to the article on Horse Pox in the Nouveau Dictionnaire de medecine et. de chirurgie veterinaires, concerning a case of an eruptive malady of the horse which was in the first place taken for aphthous stomatitis, but the inoculation of which produced Cow Pox, in the cow submitted to the experiment; or if the opportunities of the clinique had even once brought to your notice the supposed aphthous stomatitis with an eruption on the circumference of the nostrils, in the hollow of the heel, or on other parts of the body, it would no longer be possible to be misled as to its nature, and to mistake Horse Pox or equine variola.
> " In addition to these animals, I inspected in the commune of Labastide Clermont, a mare which had been especially brought to my notice as suffering in a very marked degree from the effects of the malady. I will speak of her as No. 6.
> " No. 6. A bay mare, nine years old, served the 19th and 21st of April. I was informed that this mare was at first attended to by her master, who was a farrier; and afterwards M. Averadere, veterinary surgeon at Berat, was called in. On the occasion of my visit, the 11th of May, 1880, I observed traces of an eruption around the vulva ; traces which were similar, but more extensive than those on subject No. 1 already described, so I need not again describe them. However, I will remark that lymphangitis existed in the right posterior limb, which was engorged, hot, and painful in its whole extent, and the animal walked at first with difficulty, I did not see the eruption in the hollow of the heel, but there was a greyish vaccinal vesicle, partly desiccated, near the lower commissure of the left nostril. I will now add that the proprietor of this mare had a vaccinal vesicle on the thumb of the right hand, excoriated and blackened, but recognisable, contracted in attending to his mare. This casual inoculation confirmed entirely the diagnosis which I had made the evening before at Berat, although no doubt existed in my own mind, inasmuch as the symptoms observed in the asses Aramis and Mexico, and in mares Nos. 4 and 5, already demonstrated to my eyes the existence of Horse Pox. Moreover, the day after my return to Toulouse, that is to say on the 12th of May, I directed M. Cadeac, a fourth-year student, to inoculate the crusts which I had collected at Berat two days before, from mare No. 3. This inoculation was made in the presence of the pupils, in a cow twelve years old belonging to M. Givelet, and she was placed in the hospital of the school. M. Cadeac made several punctures with a lancet on the circumference of the vulva of this animal, into which he introduced a droplet of a mixture obtained by crushing the crusts in a little water. On the 20th of May, a flattened vaccinal vesicle had formed at one of the inoculated points, having a diameter of about a centimetre ; it was depressed in the centre which was occupied by a thin crust; the periphery was markedly circular, forming a sort of crown slightly in relief. The colour of this vesicle was obscured by that of the lips of the vulva ; they were quite black in our experimental cow ; moreover, the epidermis, which was thin, and raised by the accumulated lymph at the periphery of the vesicle, presented a greyish glistening appearance. Having taken off the crust and the epidermic pellicle which covered the vesicle, we observed after a few seconds some very fine transparent amber-coloured droplets of vaccinal lymph, welling up on the surface of the skin.
> "On the 20th of May, 1880, a heifer six and a half months old, in excellent condition, belonging to M. Givelet, was inoculated with this vaccine. A great number of punctures were made around the vulva, and between the thighs, and on the right side of the udder, and on the teats. Several students revaccinated themselves, and on two of them vesicles formed. The inoculation on the heifer took perfectly, so that on the 26th of May each puncture was transformed into a flattened discoid vesicle, umbilicated in the centre, of a yellow-grey colour with an inflammatory areola, presenting, in one word, all the characters of the vesicles of Cow Pox. With the liquid contained in these vesicles I successfully vaccinated several children, and revaccinated some students, some of whom showed vaccinal vesicles. On the 26th of May, Dr. Salamon vaccinated children who had very fine vesicles. Lastly, two water-colour drawings were made by one of the most eminent artists of Toulouse, M. Loubat, one representing the vaccinal eruption of the heifer, and the other that of one of the vaccinated children, forming, in a way, unimpeachable evidence of these inoculations, which had been made in the presence of most of my colleagues and pupils.
> "No doubt can, therefore, be raised of the exactness of the diagnosis which I made as early as the 10th of May, at Berat, after seeing the mares which had been served by the stallions belonging to M. Mazeres ; and, if I insist on this question of the diagnosis of Horse Pox, when this malady is seen on mares which have been recently served, it is because it appears to me that it has not been studied in such a manner as to furnish practitioners with really useful means of recognition.
> " Some writers on pathology say that the maladie du coit may be accompanied by an eruption which some describe as papular, vesicular; others, as formed of white spots or diphtheritic ulcerations. Some assert that this eruption appears sometimes in the form of herpes or of eczema, sometimes of ecthyma, with or without the maladie du coit. M. Lafosse has even thought that it 'would not be perhaps impossible that one of the breeding animals, male or female, through sexual connection with different individuals, might generate these varieties. Fresh observations ought to be collected to establish the possibility of these results being varied by the diverse copulations of the same animal. While waiting for these observations, it appears to us prudent to admit it in practice, from the present time, not to blindly endanger the life of the reproductive animals, and also in order to free ourselves from the heavy responsibility which would encumber us under certain circumstances if the mutability of the morbid properties of the genital secretions were to be demonstrated.'
> "It is not difficult to conceive what perplexities such a doctrine would give rise to in the mind of the practitioner, and what consequences it might have, as it leads one to consider all the eruptive affections of the genital organs as originating from the same source as the maladie du coit, if not as manifestations of this disease. But observation pure and simple, and freed from all fantastic ideas, pronounces against this singular theory of the mutability of morbid properties; in other words, the maladie du coit is one thing and Horse Pox is another. And I proved this by inoculating the cow with an eruptive illness which I had observed; the inoculation gave rise, in the cow, to a perfectly genuine Cow Pox, which developed in the child to whom it was transmitted an eruption of irreproachable purity, a fact which allows us to regenerate the vaccine, and to procure for ourselves at any time, and in any place, a vaccine as pure and as active as that which Jenner himself employed. I do not assert that the maladie du coit and Horse Pox cannot exist simultaneously on the same subject. I own to having no information on this subject, and there is not, to my knowledge, any observation which proves it. Nevertheless, I consider that such a fact would not be in opposition to the principles of the pathology of the contagious maladies, and I am not unwilling to admit it as having been demonstrated. We should then know how the practitioner should act should such a thing occur, and how he can correctly foresee all the consequences of the disease which he has under observation.
> " I have no intention here of discussing the complete pathological history of the maladie du coit. I will confine myself to remarking that cutaneous plaques have been mentioned as a very important symptom in the course of this affection; they form projections of three to four millimetres, of a diameter varying from a centimetre to five centimetres; they appear on the neck, shoulder, flank, forearm, and some other parts. These plaques, are the seat of an oozing, which lasts for eight, ten, and twelve days, then they gradually become effaced without leaving any trace behind. It would be puerile to point out to the reader the great differences between this eruption of cutaneous plaques and that which characterises Horse Pox. They can be readily appreciated when we recall the characters of the vaccine vesicles and compare them to those of the cutaneous plaques, which in a way constitute the specific eruption of the maladie du coit. Nor will it be difficult to distinguish Horse Pox from the vesicular, papular, and other eruptions which have been the subjects of such varied descriptions, if inoculation in the cow formed for the practitioner the true criterion of the illness which he has under observation. But it is clear that having admitted the possibility of the development of the maladie du coit and of Horse Pox in the same subject, I ought to ascertain if there are not other points which enable the practitioner to form a well-grounded opinion about the illness under observation. The time has come to apply the data acquired by science respecting the etiology of dourine or maladie du coit. I cannot do better than reproduce here a passage from a clinical lecture of Professor St. Cyr of the School of Lyons. This learned and respected teacher, after having reviewed all the causes which have been invoked to afford an explanation of the development of dourine, formulates among other conclusions the following propositions :
> " ' That the true cause of the maladie du coit, when we know how to look for it, will be found in the importation of a foreign stallion'.
> " 'That dourine has only one known cause, contagion; that all the others to which it has been thought possible to attribute it, are more than problematical, and that in practice, as well as in theory, there is no ground for believing in them.'
> " And M. St. Cyr adds 'dourine is not an autochthonous malady born from local influences, but is, on the contrary, an exotic illness which has been imported, and the origin of which it will be always possible to trace if the practitioner exercises in his etiological investigation the attention and the perspicacity which it requires.'
> " This announcement throws light, it seems to me, on the differential diagnosis of dourine. Shall I add that even if this malady we're mistaken at its initial period, it would not be long in declaring itself by wasting, weakness, and an exaggerated sensibility of the lumbar region ; a sharp flexion of the posterior pastern joints, the appearance of cutaneous plaques, then of at first, partial paralysis, etc., all being symptoms which enable us to distinguish dourine from Horse Pox, the course of which is at the same time so simple and so mild. These are phenomena known to all practitioners who have had the opportunity of seeing the real maladie du coit.
> "To sum up, if an eruptive malady appear after coition, inoculation of the cow furnishes a valuable diagnostic sign to the observer, which it appears to me useful to insist upon, owing to the good results which it gives.
> " I now approach a question which appears to me to be not less interesting than that of the diagnosis. I wish to speak of the contagion of Horse Pox from the facts which I was able to observe at Rieumes.
> "The information furnished to me by M. Mazeres, the proprietor of this breeding establishment, concerns five out of the six mares which I examined. It establishes :—
> "That mare No. I was served 'three times by different asses, 25th, 27th, 30th of April last.' Mare No. 2, ' served twice by the same ass, Mexico, 26th, 28th of April' Mare No. 3 'served four times by the same ass, Mistigry, the 23rd, 25th, 27th, and 30th of April.' No information about mare No. 4. Mare No. 5, ' served twice by the same horse, Sultan, 22nd and 26th of April.' Mare No. 6, ' served twice by the same ass, Porthous, 22nd and 26th of April.'
> " If the reader will now recall what I have already mentioned about the state of health of the stallions of the serving stall at Rieumes, he will see that, in spite of the attention with which I examined these animals, I found on only two of them—the asses Aramis and Mexico—the characteristic eruption of Horse Pox. However, in the first place, Mare No. 3, which had been served by the ass Mistigry, on which I did not observe any eruption of Horse Pox, exhibited a splendid vaccinal eruption which had even developed on the under surface of the tail, where I collected crusts, inoculation from which proved, as we have seen, an excellent source of vaccine ; in the second place,. Mare No. 6, served by the ass Porthous, had a very confluent perivulvar eruption with consecutive lymphangitis, although I was not able to discover the smallest vesicle on the penis of Porthous or elsewhere; finally the horse Sultan showed no vaccine vesicles and nevertheless the mare No. 5, which he had served, had been infected with an eruption which had left obvious traces on the circumference of the vulva and on the buccal mucous membrane, where the vesicles were found which I have described, and which I consider to be Horse Pox. As to mares Nos. I and 2, covered by the same asses Aramis and Mexico, their contamination was explained ; but what are we to think of the appearance of Horse Pox on the mares served by stallions whose penis showed no vesicle ? A priori it may perhaps be admitted that the development of Horse Pox preceded coition, and that this eruption, being at first discrete, passed unnoticed by the groom as well as by the breeder, or indeed, that there was a simple coincidence between the occurrence of this eruption and the coitus, without &ay connecting link. These suppositions doubtless are not improbable, nevertheless neither one nor the other appears to me to be well founded considering the special seat of the eruption on the circumference of the sexual parts and its development after coition, on five out of six mares which I examined. We must then endeavour to find out how the contagion was carried when the penis of the stallion was free from all lesions.
> " Must we in this connection, admit with M. Lafosse, that the infectious agent does not exist before the coitus, that it is formed during the accomplishment of the act of copulation, doubtless at the expense of the male or female secretions, perhaps of both, and under the influence of the nervous influx or force which is accumulated in the genital organs by the friction of copulation ?
> " But I do not see on what principle or on what scientific ground this theory rests, and therefore it is quite useless to pause longer over it.
> " Let us see if it be not possible to give a more simple and rational interpretation from the facts which I have established. I think, with M. St. Cyr, that it may be possible that ' without being ill themselves, the stallions were the mediatory agents of contagion, by carrying to healthy mares virus which they had taken from diseased ones; in this way they would play the part of corps contumaces as they say in Sanitary Police, and nothing more.'
> " Do we not know that Horse Pox can be communicated by the sponge ?
> '' M. Arloing has explained the presence of this eruption on the circumference of the vulva of four mares, from the habit which the groom had of washing every morning the sexual organs of these animals with the same sponge. Moreover, the sponge is not the only object which can act as the agent in transporting the virulent matter. The hobbles, the litter, the blunt hook which is employed in the operation for javart, and even the 'finger of the operator, have communicated Horse Pox, as Trasbot and Nocard have observed in several cases ; and it would be difficult to understand why the penis of the stallion should not be a means of transporting virulent matter, in the same way as an inert body or, accidentally, the finger of the surgeon. This being explained, I will finish this paper with some practical considerations on the prophylaxis of Horse Pox. In the first place, I will remark that Horse Pox transmitted by coition is not of importance, except from the fear which it inspires in breeders, and which immediately induces them to regard this eruptive affection as syphilitic. And this alarm, consequently, brings discredit upon the breeding establishment whence the illness has spread. It is the business of the veterinary surgeon to reassure the breeders, by acquainting them with the exact consequences of this affection, of the diagnosis which they are able to establish. And, not to put it too strongly, it will also gain him the esteem and confidence of his fellow-citizens, and, I am not afraid to assert, that in thus acting he will have done more to reconcile the interests in question, than by giving himself up at random to theoretical discussions, which are necessarily useless to the practitioner who is always endeavouring to cope with the difficulties of his art.
> " The nature of the malady being perfectly recognised, is it not in all cases necessary to have recourse to sanitary precautions ? I have every reason to think, from my own observations and those of various practitioners, especially, Lautour, who saw on the penis of a stallion 'a score of little pustulous tumours, the size and shape of variolous pustules,' that Horse Pox is of no more importance when it appears after coition than when it appears under any other circumstance, for example, during an attack of strangles. And then do we not know that vaccination of the horse has been considered as a measure preventive of strangles ? Doctor Sacco, quoted by Gohier in 1813, reports that he had vaccinated 'eighty-three breeding mares and that none of them had ever been attacked with strangles.' Last year Professor Tasbert, of the school of Alfort, asserted the identity of strangles and Horse Pox, which he proposed to call variola of the horse, and recommended the same means for preventing the complications of strangles. Doubtless at the time when the mares are put to the stallions they have generally passed the age at which strangles appears, but it will be readily admitted that a fresh attack of Horse Pox, like revaccination, would best serve to guarantee the protection of the organism against a fresh attack of strangles, if such a guarantee exists. In this case, a mare which may have an eruption of Horse Pox around the vulva and on the teats, which is not unusual will herself transmit, the preservative virus to—I was going to say to vaccinate—the colt or the mule which she suckles, and this would be all for the best, as the young animal would be, for the future, protected from the serious effects of strangles.
> However this may be, Horse Pox developed around the vulva, at the end of the nose, in the mouth, and in the hollow of the heel, is always Horse Pox; therefore, when the eruption is confluent and pruriginous, simple cleanliness is sufficient or lotions of fresh water whitened by a few drops of goulard water to accelerate cicatrisation, which is generally completed by the third week. If lymphangitis supervene, simple emollient lotions, gentle walking exercise, nitrate drinks, and green food will easily subdue it. Even if the complications are very slight it may be useful to anticipate them to a certain extent.
> " With this object it will be advisable to let the stallion rest for several days when there is a confluent eruption seen on the penis, and, in the same way, mares affected with the vaccino-genic eruption must be temporally put out of use. Finally, the groom is recommended to pass a paint brush imbued with olive oil on the lips of the vulva of the mare, before she is served, as this diminishes the chances of absorption.
> "After what I have written in the preceding pages it will be understood that these precautions are only of secondary importance, and that the practitioner ought, above everything, to be able to determine the true nature of the contagious malady which he has under observation. I shall consider myself happy if the present work should prove useful in this respect."

Horse Pox in Algeria.

About eighteen months afterwards M. Peuch met with a case of Horse Pox in Algeria. An account was published in the Revue Veterinaire, July 1882.

> " The 24th of last October, being at Boufarik, I, and one of my old pupils, M. Renaud, veterinary surgeon of that commune, observed a splendid example of the vaccinogenic illness in a horse, a thoroughbred Arab, four and a half years old, belonging to one of the principal colonists of Mitidja, M. Debonno. The following are the symptoms which I observed on the subject in question :—Around the nostrils there were numerous flattened discoid, umbilicated vesicles the size of a lentil; some were in process of desiccation, others in full secretion from which, on the slightest pressure, a limpid fluid exuded of an amber colour. Towards the inferior commissure of the left nostril we noticed a superficial ulceration, the size of a silver five-franc piece, with scalloped edges, covered in part by crystalline crusts, which were yellowish and transparent ; elsewhere the skin exhibited a bright red colour, and a delicately areolar aspect. A yellowish serous discharge escaped from the left nostril. The pituitary membrane was strongly injected, notably on the side corresponding to the discharge, where on the nasal septum vesico-pustules could be seen of the size of a small lentil, of a rounded- form, and of a whitish and yellowish colour. In the mouth, and particularly inside the lips and on the lateral surfaces of the tongue, there were a multitude of small bullae or vesicles of pearly appearance and of the size of a pea ; some were isolated and prominent, the greater number confluent and as if eroded at their centre ; a viscous saliva escaped in abundance, while the mouth was being examined. The sublingual glands, especially those on the left side, were engorged, hot, and painful on pressure. The coat in patches on the lateral aspect of the neck, on the shoulders, the flanks, and in the hollow of the heel, was staring, giving the appearance of small paint brushes. On passing the hand over these parts, small lenticular nodules were felt, which were nothing else-than the vesicles of Horse Pox—some of them dry, others secreting. The animal appeared dejected, depressed ; there was, moreover, slight fever, and the appetite had fallen off. Considering these symptoms, and above all the appearance of the perinasal eruption, M. Renaud and I did not hesitate to assert, in the presence of Dr. Chafnuis, of Boufarik, that it was a case of the eruptive illness of the horse which M. Bouley has proposed to call Horse Pox,1 from two English words, horse and pox (variola). It was decided to collect the liquid which oozed from the vesicles, and to preserve it between pieces of glass. Being obliged to leave, the same day, for Oran where I was expected, I charged my old pupil, M. Renaud, to collect the virus, and I am happy to be able to say that he acquitted himself in the most satisfactory manner. We had also decided that inoculations should be made on cows.
> In a letter dated the 4th of November last, M. Renaud informed me that, having inoculated four heifers, fifteen to ten months old, with the Horse Pox in question, he had obtained Cow Pox. In the same letter M. Renaud informed me that three horses, which had eaten from the same manger as the one which we had inspected on the 24th of October last, were attacked, the 4th of November following, with very well characterised Horse Pox. It appears to me useful to mention this fact, as it indicates a mode of transmitting Horse Pox which is generally ignored. Having said this I return to our first observation.
> "On the 21st of December last I begged M. Renaud to send me some of the Horse Pox, and the vaccine which he had cultivated. In a most obliging way, for which I cannot thank him too much, my young colleague sent me on the 10th of January following, two slips of glass charged with Horse Pox virus obtained from the subject which we had visited together, and two slips with vaccine collected from the heifers which he had inoculated. I received this packet on Sunday, the 15th of January last, and the same day, with the concurrence of my colleague, Professor Bidaud, I inoculated, at the experimental farm attached to the Veterinary School of Toulouse, belonging to M. Givelet at Montredon—1st, an Ayrshire cow aged about nine years, in an advanced stage of gestation, with the dried Horse Pox previously moistened in a drop of tepid water; I made twenty punctures around the vulva and the perinaeum. 2nd, another cow, seven years old, also in a state of advanced gestation, with the Cow Pox which had been derived from the Horse Pox. I proceeded in the same way as on the previous subject. The 19th of January, the fifth day after the inoculation, I observed that on these two animals, the punctures exhibited no inflammatory process, except one or two amongst them, which were slightly papular, all the others were no longer visible, so that I thought that my culture would remain sterile. I own that I was agreeably surprised on seeing on Tuesday last, 24th of January, when I was on a weekly excursion with the pupils to the farm, that the greater part of the punctures made ten days before, which were invisible on the 19th of January, were now transformed into fine vaccinal vesicles surrounded by an areola of a rose-colour. And the 25th of January last, these two cows were taken to the Veterinary School of Toulouse where, in conjunction with M. Cadeac, teacher of the Clinique, I vaccinated two fine Dutch heifers vigorous and in good health, one aged fourteen months, the other seven months. Five days later there were as many vesicles as there had been punctures, and Drs. Armieux, Jougla, Caubet, and Parant, invited by the Director of the Veterinary School to visit the vaccinated heifers, proved the perfect genuineness of the vaccinal eruptions, which had been produced on the perinaeum and on the teats.
> " This eruption has been the starting point of cultures of vaccine on heifers and calves up to the end of last May, and the vaccine thus kept up, has been used for vaccination of about fifteen hundred persons."

In this country, it is more than probable that some of Jenner's stocks of equine lymph are still in use; but equination is not wittingly practised, for it is commonly supposed that all the lymph employed for the purposes of vaccination has been derived from Cow Pox. In France, on the other hand, it is extensively employed. M. Layet informed me that at the Animal Vaccine Station at Bordeaux, the lymph which gave most satisfaction was derived from the horse, and that he had been able on two occasions to renew his stock from equine sources.

VOLUME 2

A
LETTER
OCCASIONED BY THE MANY FAILURES OF
COW-POX.
From JOHN BIRCH, Esq.
Surgeon to His Royal Highness the Prince of Wales, &c.
ADDRESSED TO
W. R. ROGERS,
Author of the Examination of the Evidence before the House of Commons, &c, Sec.

To Mr. W. R. ROGERS.
Herts Regiment, Ipswich..
' London, July 6th, 1805.
Dear Sir,
THE able and dispassionate manner in which you have treated the argument concerning Vaccination, seems to have had its proper weight with the thinking part of mankind. I recommend you therefore to reprint your pamphlet. It cannot have too extensive a circulation. I wish it could be sent to every part of the globe in justification of English Surgery. Inoculation has hitherto been considered as distinctly the province of the Surgeon; the success of it, and the alleviation of its distressing symptoms, depend on surgical treatment. It is a melancholy consideration, therefore, to think that this branch of practice should be taken from those who alone ought to exercise it, and transferred to persons, some of whom are totally ignorant of our profession.

The experiment of Vaccination has been carried on from the commencement, to the present period, with a degree of art, which does not augur much in favour of the cause.

The number of persons adduced as supporting it when before the Committee of the House of Commons was forty; but the Public has not been told that out of this forty, twenty-three spoke from hearsay only, not from any knowledge they had acquired by practice, while the three persons who spoke against it, corroborated their evidence by proofs. Strong as this fact is, no one has taken notice of it.

When first Vaccination was recommended to me, it was announced authoritatively to be an absolute security against Small Pox; but the experiment, when tried at St. Thomas's Hospital, failed; and there it was first discovered that in a variolous atmosphere it was not to be depended on.

This in the outset did not prove much in the favour of Vaccination ; further difficulties arose from eruptions which appeared, too often in the face; but these were obviated by saying, that observation had proved the vaccine matter to be divided into genuine and spurious, and that its good or ill success depended on the period at which it was taken : on a certain day it would prove innoxious and genuine; before and after that day it could not be depended on. Sometimes the cow was to blame, and sometimes the doctor.

Thus we were left to judge by the event. If the patient should die from the inflammation of the puncture, we might then conclude the matter was not genuine; if the apothecary plunged his lancet too deep, or the infant was not of a proper constitution, the experiment might be fatal. To reason thus was to insult humanity. Alas ! how can the constitution of a child be ascertained, when only one month, or six months old ? The failures which occurred, instead of operating conviction, seemed but to change the theory of the system; new doctrines, new books, new instructions appeared every month. Even the first principle, of the origin of the disease, could not be settled. Dr. Jenner traced it from the grease of the horse's heel; and the description he gave of it, was alone sufficient to frighten us from adopting it. But this notion was soon found to be erroneous, and it is now conjectured to belong to the cow; yet after all, this animal poison is too mischievous for use, until it has been meliorated by passing through some human body, selected as the victim of the experiment.

But mere uncertainty was not the only evil attendant on Vaccination. New diseases occurred, as in the case, among others, of Rebecca Latchfield. It was studiously represented, indeed, that her affection was nothing more than common boils; but the discriminating colour, the stony hardness, and the continued succession of the tumours, together with the painful sufferings of the afflicted child, marked the novelty of the disease. Many individuals acknowledged this distinction the moment they saw her. As it is important this case should be generally known, I have procured a drawing at full length of this unhappy little sufferer, which may hereafter be presented to the Public.

How far it was well judged, or politic, to direct our soldiers and seamen to become the subjects, whereon a doubtful experiment should be tried, I do not mean to enquire. At all events, it would have been more regular, and more to the interests of Society, as the experiment was surgical, to have consulted the College of Surgeons, and to have had their collected approbation before a parliamentary reward was adjudged. In all cases where Parliament has neglected to do this, it has committed an error; as in the instance of Mrs. Stevens' medicine for dissolving the stone.

But was it not highly reprehensible to conceal industriously all the cases which occurred to the prejudice of Vaccination, while everything that could tend to lessen the credit of Inoculation was most artfully propagated ?

The facts which you have adduced are so strong in themselves, and the authority on which they rest so incontrovertible, that they entirely subvert the data laid down by the Committee of the House of Commons. Yet the argument might have been treated in another way, and these questions asked.
I. Is there any disease consequent to Small Pox Inoculation which is not a natural disease, and which may not be produced equally by other exciting causes ?
II. Does the puncture of Inoculation ever produce such an inflammation of the arm as to kill the patient ?
III. Can the artificial introduction of variolous matter produce any disease but genuine Small Pox ?
IV. Are not the symptoms of inoculated Small Pox, after two years old, generally as safe and as mild as those of the kindest Vaccination ?
V. Did the justly celebrated Baron Dimsdale, in his extensive practice, both abroad and at home, during the space of forty-five years, ever lose three of his patients ?

I affirm that the negative must be replied to each of these questions. What then is there left for Vaccination to do, that may not be done more advantageously by Inoculation?

But the object, of the projectors of Vaccination was not, I fear, so much the desire of doing general good, as that of securing to themselves, and to Men-midwives, if the experiment should succeed, the absolute command of the nurseries, to the entire exclusion of the Surgeons.

This being really the state of the case, I must call it an unworthy expedient, to alarm the ignorant multitude with the dangers of Inoculation ; an enemy that had been laid at their feet by the firm and steady exertions of the great and good Baron Dimsdale.

A monthly Medical Journal, which has spread the mischief of Vaccination widely, and which, till the last month, has been shut against every statement which could affect its credit, now acknowledges failure upon failure, attested by one practitioner after another. But we are little obliged for these tardy confessions, since the Public has been some time in the possession of the facts, together with many others; and they are now acknowledged, because they can no longer be concealed. I again affirm, that the Public are beforehand with the Medical Journals ; they have indeed been too long misled by the charm of novelty, but they perceive their error; and they have loudly called out for regular Inoculation, to prevent the mischiefs of natural Small Pox, which has appeared epidemical in many places, and proved fatal in cases where Vaccination had been relied on.

I forbear to say more on this subject at present. I have collected materials enough to satisfy the Public of the validity of the reasons on which I have uniformly objected to the practice of Vaccination. That I should come forward, is a duty I owe both to them and myself. Should I contribute towards dispelling that mist of prejudice, which has obscured the judgment of many well-intentioned people, and many able practitioners, I shall have just cause to rejoice. To attempt to vindicate truth and expose error, is the noblest exertion of our faculties : to succeed in the attempt, is to obtain the most exalted gratification a reasonable being can desire.

I am,
Dear Sir,
Your faithful friend,
John Birch.

Spring Gardens,
July 6th, 1805.

P..S.—Every post brings me accounts of the failures of Vaccination. From Hertfordshire, I have notice of four cases within the last month, two of which were fatal; but as I do not admit Hearsay Evidence, I must enquire more particularly before I publish them.—However, I have just seen a child in Orange Court, Swallow Street, vaccinated five years ago by a Man-midwife, who is not only the strongest advocate for Vaccination, but is considered to be one of its most skilful practitioners. By him this child was pronounced to have had the genuine sort; and so strong was his conviction of it, that he took matter from him to vaccinate many other patients with; yet this very Child is now full of the true, not of the supposed Small Pox.

The mother says the Small Pox is not in the Court—and that the child has not been in the way of infection to her knowledge. Add this case to the confessions of the Monthly Journal, and to Dr. Moseley's* list, and what is the conclusion we are to draw ?

* Vide Moseley on Lues Bovilla, 2nd edit.
There is but one; namely, that Vaccination neither secures the patient from catching the Small Pox by variolous infection, nor, when so caught, lessens the danger of disease. For my own part I tremble to think on the perils which await Society, from the prevalence of Vaccination. Unless it be stopped, we shall see Small Pox at no very distant period recur in all the terrors with which it was first surrounded; desolating cities like the plague, and sweeping thousands from the earth, who, lulled into a false security, will have fatally deprived themselves of the only proper means of defence.