Chapter XXV: Jenner’s Later Writings

Jenner’s later writings were chiefly apologies for the failures of vaccination. His position was one of much difficulty, and its peculiarity is rarely, if ever, recognised. For example, how few know that his _Inquiry_ published in 1798, “that master-piece of medical induction,” according to Mr. John Simon, was kept out of print and referred to as rarely as possible after 1801-2.

“Why?”

The answer to the question is so important that at the risk of repetition I give it explicitly.

The _Inquiry_ was suppressed because of its ascription of cowpox to horsegrease.

It was the belief of dairy-maids in Gloucestershire that to have had cowpox was to be secure from smallpox. Jenner was much impressed by the rustic superstition, and brought it so persistently before his medical brethren at their convivial assemblies, that they threatened to expel him if he bored them any longer with the subject. “It is true,” they said, “that the maids believe an attack of cowpox keeps off smallpox, but we know they are wrong; for we are all familiar with cases of smallpox after cowpox.”

Thus frustrated, Jenner’s ingenuity took another turn. It was the belief of farriers that if infected in dressing horses’ greasy heels, they too were secure from smallpox. The area of this conviction was narrower than that of the dairy-maids, farriers being neither so numerous, nor so observant of their beauty: but Jenner entertained their faith and converted it to his purpose.

Horsegrease protected from smallpox, if cowpox did not. But might there not be one sort of cowpox that answered to the dairy-maids’ faith, if another sort did not? Happy thought! The defensive sort was derived from the horsegrease which protected the farriers: the non-defensive originated spontaneously on the cows. Men, fresh from handling horses’ greasy heels, milked cows and communicated to them the horses’ disease. Milkmaids, who in turn contracted from the cows that sort of pox, were like the farriers secure from smallpox, yea securer; whilst milkmaids who contracted pox spontaneously developed on cows were not secure. The milkmaids’ superstition was therefore justifiable: they were right and they were wrong--right when they got pox through the cow from the horse; wrong when they got pox from the cow simply.

Why then, it may be asked, did not Jenner dismiss the cow from consideration? Why did he not base his prescription on the farriers’ experience, and use and recommend horsegrease exclusively for inoculation? The question is an obvious one, but it is not easy to make out Jenner’s answer with precision. His assertion was, that--

The virus from the horse is not to be relied upon as rendering
the system secure from variolous infection, but the matter
produced by it on the nipple of the cow is perfectly so--

which was to say that horsegrease attained its highest prophylaxy after transmission through the cow.

Such was the doctrine of the _Inquiry_, “that master-piece of medical induction.”

When the doctrine came to be reduced to practice, difficulties arose. Cowpox was considered wholesome and credible, whilst horsegrease was repulsive and incredible. Still fact was fact; and many were ready to accept horsegrease through the cow, or without the cow, if such indeed were the source of the new salvation. Cowpox proved to be a rare commodity, whilst horsegrease was common, and numerous attempts were made to produce cowpox by means of grease, but ineffectually. At some attempts, Jenner officiated. Marshall records that--

Mr. Sewell, Assistant Professor at the Royal Veterinary College,
informs me that he was a witness to a series of experiments,
twice repeated, at the College in the presence of Dr. Jenner,
Dr. Woodville, Mr. Wachsel, and Mr. Turner, with a view to
produce the vaccine disease on the teats of a cow. The matter of
grease had been immediately taken from the horse, and variously
applied by long continued friction, punctures, scarifications,
and by scratching the surface with a needle; but from these
trials neither inflammation, nor any affection resembling a pock
resulted.[190]

To this discomfiture Jenner had to submit. His ascription of cowpox to horsegrease was stigmatised as an error of which the less that was said the better. It is true that other experimenters were more successful, and that Loy of Whitby and Sacco of Milan dispensed with the cow as a superfluity and used matter direct from the horse for inoculation, passing the virus from arm to arm into general circulation until what was equine was lost sight of and indistinguishable from what was vaccine; but Jenner did not care to be justified at the risk of his popularity and the money on which he had set his heart. He saw how the wind of public favour was blowing, and went with it. Since horsegrease was disliked, he consented to its oblivion. Pearson, the chief promoter and organiser of vaccination, scoffed at horsegrease, and used spontaneous cowpox, which Jenner knew was of no avail against smallpox; but he entered no protest upon that score. On the contrary, he let the futile practice go on; he claimed it as his own; and he set about manufacturing excuses for the failures which were imminent.

Spurious cowpox was one of the most dexterous of these excuses. If injury or smallpox followed vaccination, the disaster was ascribed to spurious cowpox. Jenner’s _Further Observations_, published in 1799, was designed to teach “how to distinguish with accuracy between that peculiar pustule which is the _true_ Cow Pock and that which is _spurious_;” and in his _Origin of the Vaccine Inoculation_ in 1801 even greater stress was laid on the distinction. By and bye, however, the excuse worked more harm than advantage. People got terrified with the mischiefs ascribed to spurious cowpox, and as which was genuine and which spurious was only discoverable in their consequences, they began to decline to have either. It then became expedient to deny spurious cowpox, which Jenner did. He confessed to the Royal College of Physicians that there was not a true and a false cowpox; and that by spurious cowpox he “meant nothing more than to express irregularity in the form and progress of the vaccine pustule from which its efficacy is inferred.”

In view of facts like these, there is little cause for surprise that the publication of Jenner’s _Inquiry_ with its two supplements was not continued. What he set forth as essential was treated as illusory, whilst the cowpox in 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 master-piece 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.[191]

It clearly appears that this disease, Cowpox, leaves the
constitution in a state of perfect security from the infection of
the Smallpox.[192]

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.[193]

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?[194] Why, indeed! Still 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.[195]

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 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![196]

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.[197]

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 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.[198]

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.[199]

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.[200]

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 extreme ignorance of medical men on this subject will destroy the advantages which the world ought to derive from the practice.”[201]

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 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 of it is that the patient does not
receive that _perfect_ security from Smallpox infection which is
given by the perfect pustule.[202]

These complaints of the indifference of the medical world to his prophesying, show how completely the business of vaccination had passed out of Jenner’s hands. The influence of herpes on vaccination, although declared by him to be of the utmost importance, even to the extent of imperilling the advantages of the practice, was disregarded as unworthy of serious attention.

Another of Jenner’s apologetics was a pamphlet in 1808[203] designed to explain away the failure of the variolous test--the test that deceived so many in the early days of vaccination. The inoculated with cowpox were inoculated with smallpox, and when the smallpox did not “take,” it was said, “Behold the perfect protection!” The smallpox inoculators complained bitterly of the hocus-pocus. “No wonder,” they said, “that when the system is in a fever with bestial corruption, that human pox will not ‘take,’ but try after awhile.” And they did try after awhile, and it was found that the vaccinated could be inoculated with smallpox like the unvaccinated. Indeed, when it was seen that the vaccinated fell victims to smallpox, many who had been vaccinated resorted to the smallpox inoculators for their supposed superior protection, and received it without hindrance from their previous vaccination. It therefore became judicious to disown the variolous test; but neither in this case was the surrender frankly made, but with prevarication that deprived it of all grace. What the smallpox inoculators maintained, Jenner had to allow, but after this fashion--

My principal object is to guard those who may think fit
to inoculate with variolous matter after Vaccination from
unnecessary alarms; a pustule may sometimes be thus excited,
as on those who have previously gone through Smallpox; febrile
action in the constitution may follow; and, as has been
exemplified, a slight eruption.

For the variolous he recommended the substitution of the vaccine test; saying--

At the commencement of Vaccination, I deemed the Variolous Test
necessary; but I now feel confident that we have one of equal
efficacy, and infinitely less hazardous in the re-insertion of
the vaccine lymph--

Which was to say that vaccination immediately after vaccination would be found impossible--the later practice of periodical re-vaccination being unforeseen.

Jenner might have perceived that after his proclamation of the influence of herpes on vaccination, there was nothing to be said for the variolous test. When he consented to run vaccination on the same terms as variolation, and admitted that it would be wrong to expect more from the one practice than from the other, he was bound in consistency to allow that if vaccination was frustrated by eruptions of the skin, it was matter of consequence that variolation should be frustrated by the fever of vaccination. He informed Dillwyn that he destroyed cutaneous eruptions by the application of _unguentum hydrargyri nitrati_, and then vaccinated with success. The smallpox inoculators did so likewise. When the irritation induced by vaccination had had time to subside, they too variolated with success.

The letter to Dillwyn, 1818, contains some other points which it is instructive to note. For example, the following passage proves two things, first, how notorious had become vaccination failures; and, second, how vaccination, from an easy art that any one might practise, had been converted into a mystery to which even “an eminent surgeon” might be unequal. Jenner says--

One word more with respect to prejudice. How frequently have we
seen in the public prints paragraphs of this description--“A
gentleman’s family, consisting of three or four or half-a-dozen
children, were vaccinated by an eminent surgeon, and all went
through the disease in the most satisfactory manner, and were
pronounced safe; yet, on being exposed to the infection of
the Smallpox, they all had the disease, but happily they all
recovered.” Here, Sir, the mind becomes entangled with a false
association. The public conceive that _an eminent surgeon_ must
be a perfect master of this little branch of our art; but it
often happens that he has not stooped to look at anything beyond
its outline; and when deviations arise in the progress of the
pustules [as from herpes] to that extent which I have pointed
out as momentous, they are passed by without attracting any
particular attention.

A report having got abroad that Jenner had renounced his faith in vaccination, he replied to Dillwyn--

My confidence in the efficacy of Vaccination to guard the
constitution from Smallpox is not in the least diminished.
That exceptions to the rule have appeared, and that they will
appear, I am ready to admit. They have happened after Smallpox
Inoculation; and by the same rule, as the two diseases are so
similar, they will also happen after Vaccine Inoculation.

In presence of such a declaration, it is easy to understand why the _Inquiry_ with its supplements was kept out of print, and never referred to. His confidence in vaccination not in the least diminished! In the words cited, he surrendered afresh the claim with which he started, and for which he was paid, namely, that inoculation with cowpox rendered the constitution proof against smallpox for life, and that the protection thus afforded was without precedent in medical experience.

Having thus, under stress of necessity, reduced vaccination to the level of variolation, and tried to shelter the failures of the one practice under those of the other, the spirit of the old quack surviving, he went on to prophesy in the familiar strain--

It is a curious and most delightful fact that Smallpox is flying
before Vaccination in all directions. In a wide district around
me, embracing the most populous part of the county of Gloucester,
the Smallpox is scarcely heard of; and if it does happen to
appear from infection brought by the wandering pauper, it either
finds itself insulated, or is rendered incapable of spreading
by giving immediately the vaccine security to those within its
atmosphere who may happen to remain unprotected.

With Jenner’s turn for romance, there is no need for dealing with a statement like the foregoing seriously, else we might ask what was the prevalence of smallpox in Gloucestershire before vaccination? and to what extent had it been cultivated by inoculators? Throughout England there was a remarkable subsidence of smallpox precedent to the introduction of vaccination (for which vaccination obtained the credit), which subsidence was no doubt accelerated by the cessation of variolation. Jenner resumes--

Wherever Vaccination has been _universally_ practised, there the
Smallpox ceases to exist. It matters not how wide the district,
or how populous the city, the result is, and, from the nature
of things, must be the same. There is scarcely a part of the
civilised world that cannot bear testimony to the truth of this
position. For extent of territory, we may turn our eyes to our
possessions in the East, and to various parts of South America;
and to towns and cities, many of the most conspicuous in Europe.

In the island of Ceylon, the ravages of Smallpox were dreadful,
although many efforts had been made to lessen its fatality by
Variolous Inoculation. This, wherever it was practised, produced
a spreading of the disease, and made a bad matter worse; so that
the people would have nothing to do with it. But after a little
time they took to Vaccine Inoculation very readily, and Smallpox
became totally extinct.

From Sweden, too, we have a report that proves the extinction of
Smallpox throughout the kingdom. Now as the good sense of the
Swedes brought about this happy event, why should not Britain
avail herself of the great gift, and employ it to the same
effect? Here the Boon is distributed with a partial and a sparing
hand, and consequently Smallpox still exists in several parts of
our island.

There was no checking Jenner when he rose into rhodomontade about the myriads of Asia and the vastness of America, but descending to the definite in Ceylon and Sweden we can test him with precision, and as to both we shall find his statements at wide variance with facts. For the present, however, let us keep to our own country, and note especially what he had to assert of London in 1818--

Nevertheless I have the happiness to say, that since the first
promulgation of my discovery in 1798, the deaths of Smallpox in
the British Realms, according to the best estimates I can form,
are reduced from more than 40,000 to less than 6,000 annually.
The metropolis for the last ten or twelve years exhibited a
reduction of about one half only; but during the last two years,
Vaccination has been more extensively practised than ever, both
from the benevolence of private individuals and the faculty,
and by public institutions; and this year, 1818, promises a far
greater reduction in the number of deaths than any that has
preceded it.

In London in 1818 the deaths from smallpox were low (421); but a single year is of little account, and must be viewed in relation to preceding years. Here we have a statement for the decade, 1811-20, taken from the metropolitan Bills of Mortality.

Burials from From From From
YEARS. all diseases. Smallpox. Fevers. Measles.
1811 17,043 751 906 235
1812 18,295 1287 783 427
1813 17,322 898 714 550
1814 19,783 638 908 817
1815 19,560 725 1309 711
1816 20,316 653 1299 1106
1817 19,968 1051 1299 725
1818 19,705 421 1170 728
1819 19,228 712 1150 695
1820 19,348 792 1156 720
------- ---- ------ ----
190,568 7928 10,694 6714
1801-1810 185,737 12,534 16,204 5680
1791-1800 196,801 18,477 19,880 2707

From this statement we see that the decrease in London smallpox that set in toward the close of the 18th Century was maintained; but that vaccination had aught to do with the decrease there is no reason to believe--unless in so far as the new practice discouraged variolation. How, we ask, could the vaccination of one-tenth of the Londoners (if so many) reduce the smallpox among nine-tenths? We have also to observe that mortality from fevers abated in common with smallpox; and it cannot be pretended that that abatement was also due to vaccination! The rational assumption is, that what diminished fevers in London, likewise diminished smallpox. Nor should we overlook the fact, that as the deaths from smallpox declined, those from measles increased; nor the probability that many deaths formerly ascribed to smallpox were derived from measles, and that part of the decline in one column is accounted for by the increase in the other.

Jenner’s assertion, that the national mortality from smallpox had been reduced from more than 40,000 to less than 6000 annually, had no basis whatever in reality. As we know, the 40,000 deaths were got by multiplying the deaths of a bad year of London smallpox by the population of the United Kingdom--as if London were the standard of England, Ireland, and Scotland! How he obtained the reduced number of 6000 we are left to conjecture. In reviewing Jenner’s writings we are startled with his inconsistencies, and scarcely less with the carelessness and credulity of his adherents. He set out with the common knowledge that cowpox did _not_ prevent smallpox, and for that reason he substituted pox generated by horsegrease on the cow. Horsegrease cowpox could not, however, be procured on demand; and was, moreover, disliked on the score of its origin; and cowpox was resorted to by Pearson and Woodville, and diffused everywhere with acclamation; and Jenner did not only not object, but took credit, and actually was allowed to take credit for the pox he had described as ineffective for the purpose designed! By and bye cowpox from horsegrease, or horsepox, according to the original recipe, was obtained and brought into circulation with Jenner’s sympathy, if without his open approval--he discerning that praise and pay were not to be had from that notion. After a while, horsegrease, or horsepox, was used for inoculation without the intervention of the cow; and that too entered into currency as vaccine, Jenner himself employing and distributing it, although according to his _Inquiry_ it was not to be trusted to prevent smallpox.

I repeat these facts, even at the risk of tedium, because it is essential to have them clearly apprehended. For at least three descriptions of virus Jenner stood responsible, namely--

I.--Horsegrease Cowpox--the virus warranted in his _Inquiry_.

II.--Cowpox, known by Jenner to be ineffective in preventing smallpox, but favoured by the medical profession and the public.

III.--Horsegrease (said to have been horsepox), also described by Jenner as ineffective, but latterly used and diffused by him.

To which of these did he attribute the success claimed for vaccination? Apparently to all indifferently; but if one were as good as the others, why did he not say so, and proceed to explain how it was that cowpox did not save the Gloucestershire milk-maids, nor horsegrease the farriers from smallpox? Was it that the power to put such questions, and to answer them, does not consist with the quack’s intelligence; and that in his lucre he rests content? Observe, too, how when credit was to be had for London vaccination, Jenner took it, though at mortal enmity with the chief agent in the work, repudiating Walker’s practice as subversive of principles he considered essential to success.

Jenner’s final publication in 1822 had nothing to do with vaccination, but was a bid for fame in a new direction.[204] It was an attempt to originate a new method of cure by irritating the skin with tartarated antimony. He had dabbled with the chemical when a young man, and John Hunter had suggested that his preparation should be sold and puffed as Jenner’s Tartar Emetic. In his last years he returned to it, and produced a series of cases to prove how many diseases might be alleviated and removed by using it as a counter-irritant--just as in the _Inquiry_ he recommended cowpox inoculation with the same intention. The matter does not concern us further than to observe that the vesicles and scars produced by tartarated antimony are almost indistinguishable from those of vaccination; and that Hufeland, the German Nestor of Medicine, taught and proved that tartar emetic was every whit as effective against smallpox as cowpox--an opinion from which I see no reason to dissent.

FOOTNOTES:

[190] _A Popular Summary of Vaccination with reference to its Efficacy and Probable Cause of Failure._ By John Marshall, M.R.C.S. and District Vaccinator of the National Vaccine Establishment. London, 1830. Pp. 96.

[191] _Inquiry_, 1798, p. 7.

[192] _Ibid._, p. 58.

[193] _Petition to the House of Commons_, 1802.

[194] Jenner to Dunning, 23rd Dec., 1804. Baron’s _Life of Jenner_, vol. ii. p. 26.

[195] _Facts for the most part unobserved, or not duly noticed respecting Variolous Contagion._ London, 1808, 4to, pp. 17.

[196] _A Continuation of Facts and Observations relative to Cowpox._ By Edward Jenner, M.D. London, 1801.

[197] Baron’s _Life of Jenner_, vol. ii. p. 28.

[198] Baron’s _Life of Jenner_, vol. i. p. 449.

[199] _Ibid._, vol. ii. p. 344.

[200] _Ibid._, vol. ii. p. 26.

[201] _Life of Jenner_, vol. ii. p. 223.

[202] _Letter from Dr. Edward Jenner to William Dillwyn, Esq., on the Effects of Vaccination in Preserving from the Smallpox._ Philadelphia Vaccine Society. Philadelphia, 1818. Pp. 20.

[203] _Facts for the most part unobserved, or not duly noticed, respecting Variolous Contagion._ London, 1808. 4to, pp. 17.

[204] _A Letter to Charles Henry Parry, M.D., on the Influence of Artificial Eruptions in certain diseases incidental to the Human Body; with an Inquiry respecting the probable advantages to be derived from further experiments._ By Edward Jenner, M.D., LL.D., F.R.S., M.N.I.F., etc., and Physician to the King. London, 1822. 4to, pp. 68.