in

as essential was treated as illusory, whilst the cowpox which he had taught there was no security had been brought into use everywhere. Why therefore embarrass himself with proclamations of his own blunders? The believers in vaccination were good-natured and incurious, and he had their homage, which was agreeable and profitable, and why should he dissipate it? The Inquiry was printed for the third time in 1801, but" this masterpiece of medical induction" has never been republished; and the probability is, that if ever reproduced, it will be to prove to the world the emptiness of its author's pretensions.

Jenner's original promises of immunity from smallpox by inoculation with horsegrease cowpox were absolute. Thus he wrote—

The person who has been affected with Cowpox Virus is for ever after secure from the infection of the Smallpox.*

It clearly appears that this disease, Cowpox, leaves the constitution in a state of perfect security from the infection of the Smallpox. t

Cowpox admits of being inoculated on the human frame with the most perfect ease and safety, and is attended with the singularly beneficial effect of rendering through life the person so inoculated perfectly secure from the infection of the Smallpox.‡

Experience was not slow to demonstrate the futility of these assurances. At first the facts were flatly denied: it was impossible for smallpox to succeed cowpox. The evidence, however, grew too strong to be outsworn, and then it was said the cowpox must have been spurious. As failures accumulated over the operations of Jenner himself and his choice disciples (who were naturally presumed to know and avoid spurious cowpox) they began to lay great stress on the fact that smallpox itself did not always avert a subsequent attack; and if smallpox did not save from smallpox, why, they demanded, should cowpox be expected to do more ?S Why, indeed! Still

* Inquiry, 1798, p. 7.

+ Ibid., p. 58. + Petition to the House of Commons, 1802.

§ Jenner to Dunning, 23rd Dec., 1804. Baron's Life of Jenner, vol. ii. p. 26.

the cases of smallpox after cowpox were as scores to those of smallpox after smallpox, and then the argument was reduced to a competition between variolation and vaccination. "You inoculators with smallpox," said the vaccinators, "are continually having smallpox after variolation, and why should we be expected to be more successful?" Why, indeed! The inoculators with smallpox in turn denied that after efficient variolation. smallpox ever occurred, or could possibly occur; and thus the wrangle went on. One thing was plain and certain -the original claim of Jenner for the absolute infallibility of Horsegrease Cowpox as a preventive of Smallpox was reduced and surrendered bit by bit until it came to this at last-it made Smallpox milder!

These repeated surrenders were, however, never ingenuous. Mistakes are inevitable, and they are forgiven when frankly confessed; but frank confession was not Jenner's habit. When vaccination failures had become notorious in 1808, he had the hardihood to assert, that from the outset he had recognised that as smallpox did not always avert smallpox, neither did he expect cowpox to do so; and cited as proof of his prescience this passage from Further Observations in 1799

It should be remembered that the constitution cannot, by previous infection, be rendered totally insusceptible of the variolous poison; neither the casual, nor the inoculated Smallpox, whether it produce the disease in a mild or violent way, can perfectly extinguish the susceptibility.*

Here Jenner made a bold draft on his reader's ignorance. It was his claim for horsegrease cowpox that it conferred an absolute security from smallpox without any qualification whatever. The assumed prescience in 1799 is completely belied when we refer to his arrogant manifesto of 1801. These are his words

The scepticism that appeared amongst the most enlightened of medical men, when my sentiments on Cowpox were first promulgated, was highly laudable. To have admitted the truth

Facts for the most part unobserved, or not duly noticed respecting Variolous Contagion. London, 1808, 4to, pp. 17.

of a doctrine, at once so novel and so unlike anything that ever appeared in the Annals of Medicine, without the test of the most rigid scrutiny, would have bordered upon temerity; but now, when the scrutiny has taken place, not only among ourselves, but in the first professional circles in Europe, and when it has been uniformly found in such abundant instances, that the human frame, when once it has felt the influence of the genuine Cowpox in the way that has been described, is never afterwards, at any period of its existence, assailable by the Smallpox, may I not with perfect confidence congratulate my country and society at large on their beholding, in the mild form of Cowpox, an antidote that is capable of extirpating from the earth a disease that is every hour devouring its victims; a disease that has ever been considered as the severest Scourge of the human race! *

Cowpox was thus set forth as a prophylactic with powers hitherto unknown and unique; so that Jenner was cut off from the claim of its equivalence with smallpox in character and consequences. He knew in 1799, as we have seen, that infection with smallpox did not render the constitution proof against the subsequent influence of the disease; but in 1801, as we see, it was his express contention that what smallpox failed to do that cowpox did-it protected the constitution perfectly and for ever from smallpox, and nothing to compare with it had ever appeared in the Annals of Medicine. It was only under the pressure of exposure and defeat that he humbled himself to write to Dunning, 1st March,

1806

The security given to the constitution by Vaccine Inoculation is exactly equal to that given by the Variolous. To expect more from it would be wrong. As failures in the latter are constantly presenting themselves, we must expect to find them in the former also. †

To this pass was the infallible preservative from smallpox, with nothing to match it in the Annals of Medicine, reduced within the experience of seven years!

The most thorough-going and far-reaching of Jenner's

A Continuation of Facts and Observations relative to Cowpox. By Edward Jenner, M.D. London, 1801.

+ Baron's Life of Jenner, vol. ii. p. 28.

excuses for vaccination failures were herpetic affections of the skin. In his journal we read—

Inoculated C. F. a second time. It is very evident that the affection of the skin called red gum deadens the effect of the Vaccine Virus. This infant was covered with it when inoculated four days ago. The same happened with Mrs. D.'s infant.*

To Mr. Dunning he wrote from Cheltenham, October 25th, 1804

How frequently does the Vaccine Disease become entangled with herpes! I see that the herpetic fluid is one of those morbid poisons which the human body generates, and when generated, that it may be perpetuated by contact. Children who feed on trash at this season of the year are apt to get distended bellies, and on them it often appears about the lips. This is the most familiar example that I know. A single vesicle is capable of deranging the action of the vaccine pustule. Subdue it, and all goes on correctly.t

And again to the same correspondent, 23rd December, 1804

My opinion is that the chief interference with the success of Vaccination is herpes in some form or another. I have discovered that it is a very Proteus, assuming as it thinks fit the character of the greater part of the irritative eruptions that assail us. ‡

Having thus detected an all-sufficient explanation of the failure of vaccination to prevent smallpox, he communicated his discovery to the Medical and Physical Journal, August, 1804, in a paper entitled, "On the Varieties and Modifications of the Vaccine Pustule occasioned by an Herpetic State of the Skin," but he complained to Dunning "that it seemed not to have excited the slightest interest." In order to call attention afresh to the subject, he had the article reprinted as a pamphlet at Cheltenham in 1806 and at Gloucester in 1819, but in vain. He complained to Baron in 1817 that he could not get the Board of the National Vaccine Establishment to attend to his cautions touching the interference of cutaneous diseases with the progress of the vaccine vesicle. "I am afraid," he observed, "that the

*Baron's Life of Jenner, vol i. p. 449. +Ibid., vol. ii. p. 344. ‡ Ibid., vol. ii. p. 26.

extreme ignorance of medical men on this subject will destroy the advantages which the world ought to derive from the practice.'

What of course medical men with the least common sense perceived was, that the excuse provided for vaccination failures was too liberal to be worth anything. If the least cutaneous eruption was sufficient to frustrate vaccination, what operation could be pronounced efficient? for it could scarcely be intended that every patient should be stripped to the skin and minutely examined for herpetic vesicles. There was nothing transitory in Jenner's opinion about herpes: he harped upon its mischiefs and omnipresence to the close of his life. William Dillwyn of Walthamstow having asked him for any observations that occurred to him on the practice of vaccination for the benefit of Friends in Philadelphia, Jenner replied in a letter dated Berkeley, 19th August, 1818, in which we find these remarks

I must candidly acknowledge that I am not at all surprised that a partial prejudice should now and then lift up its head against Vaccination. It is called into existence, not from anything faulty in the principle, but from its wrong and injudicious application. For example, a child, or a family of children, may be in such a state, that the action of the vaccine fluid when applied to the skin shall be either wholly or partially resisted. It may either produce no effect at all, or it may produce pustules varying considerably in their rise, progress and general appearance from those which have been designated correct. It was about the year 1804 that I was fortunate enough to discover the general cause of these deviations, and no sooner was it fully impressed on my mind, than I published it to the world. Yet few, very few indeed, among those who vaccinate, have paid any attention to it; yet I am confident, from the review of the practice on an immense scale, that it is a matter which has a greater claim on our attention than any one thing besides connected with Vaccination-indeed I may say than any other thing. What I allude to is a coincident eruptive state of the skin, principally bearing what we call the herpetic or eruptive character. If we vaccinate a child under its influence, we are apt to create confusion. The pustule will participate in the character of the herpetic blotch, and the two thus become blended, forming an appearance that is neither vaccine nor herpetic; but the worst

* Life of Jenner, vol. ii. p. 223.