As human nature exists, it was not extraordinary that Jenner should feel anxious over the occupation of ground he considered his own; but at the same time it is obvious, that Pearson had done nothing wrong, nothing that was not allowable, nothing indeed that was not praiseworthy. He allowed Jenner full credit for having advertised the Gloucestershire faith in cowpox, and for the production of certain evidence for that faith; but he set aside Jenner's prescription of horsegrease cowpox, and was making use of a form of cowpox that Jenner had explicitly condemned. Whilst Jenner, too, had excited curiosity, he did nothing, or could do nothing, to satisfy it; and it was idle to expect the world to await his convenience: nor was Pearson the man to rest content where action was possible. As he said—

From the time of the publication of the Inquiry in June, 1798, the author contributed no further inoculated cases to the end of that year; nor could I do more than investigate the history of the Cowpox principally by inquiries among provincial physicians and farmers, from whom I was enabled to confirm some of the facts in Dr. Jenner's book, and to render doubtful or disprove others, and to bring to light new observations.*

Jenner was not slow to repond to his nephew's summons to London. He left Berkeley on the 21st of March, and remained in town until the 11th of June, visiting medical men, asserting his own claims, and counter-acting the operations of Pearson and Woodville.

In Dr. Pearson's circular, it will be observed, that he described inoculation with cowpox as attended with eruptions in some cases, which could not be distinguished from smallpox. So far as Pearson and Woodville were concerned, it was an unfortunate statement, and gave Jenner an advantage over them which he used unsparingly to their discredit.

Jenner's claim for inoculation with cowpox was, that it excited a fever that was not infectious and was without pustular eruptions; and here was Dr. Pearson setting up as his critic, and Dr. Woodville assuming to develop

*Examination of Report of Committee of House of Commons, 1802.

his practice, and producing a disorder that was indistinguishable from smallpox! Such presumption and ignorance deserved to be hooted.

What was the explanation? Simply this: that Woodville conducted some of his cowpox inoculations in the variolous atmosphere of his Hospital, and that he thereby communicated smallpox and cowpox simultaneously. In a scientific sense, the experience was valuable; it proved that it was possible to have cowpox and smallpox at the same time that neither disease superseded or nullified the other.

Woodville tried to vindicate himself, and in his failure magnified Jenner's triumph still further. Yet he had much that was reasonable to say for himself. For example, he had transmitted to Jenner some of the virus. from one of the first of his cowpox inoculations in January, and with it Jenner operated on twenty persons, reporting to Woodville

BERKELEY, February, 1799.

The rise, progress, and termination of the pustules created by the virus were exactly that of the true Cowpox.

Nevertheless, wrote Woodville

This virus which Dr. Jenner declared to be perfectly pure and genuine was taken from the arm of an hospital patient who had 310 pustules, all of which suppurated.

Woodville also argued, that "Cowpox, as casually produced by milking infected cows, differs considerably from that which is the effect of inoculation"; which Jenner attested in saying—

Four or five servants were inoculated at a farm contiguous to Berkeley last summer with matter just taken from an infected Cow. A little inflammation appeared on all their arms, but died away without producing a pustule; yet all these servants caught the disease within a month afterwards from milking the infected Cows, and some of them had it severely.*

Others maintained that the cowpox which saved milkmaids from smallpox was a much severer affection than

*Further Observations on the Variola Vaccinæ, 1799.

that induced by Jenner's lancet, and that it was folly to assume their equivalence. There was force in the argument; for every one then knew how much the issue of smallpox inoculation depended on the mode of its performance. The infection when communicated through the skin was usually much less severe than when communicated by incision; and Jenner related how a country inoculator, who liked to "cut deep enough to see a bit of fat," was the death of his patients on every side. The human body is of infinite delicacy and complexity, and we are sure to find ourselves at fault when we deal with its mysteries according to our crude and inanimate logic. It is by experiment and not by syllogism that physiological truth is verified.

Whatever might be the perils, immediate or remote, of inoculation with cowpox, it was not attended with smallpox eruption; and at last it became manifest to Woodville himself, that the virus he had used, and the virus. he had distributed, which had produced such eruption, was the virus of smallpox.

After much controversy and many experiments these conclusions were arrived at

1. That when a person was inoculated with smallpox and cowpox about the same time, both inoculations proved effective. There was a pustular eruption on the skin from the smallpox, and the cowpox vesicle reached maturity in the usual number of days.

2. These effects took place, without much variation, in all cases where the interval between the two inoculations did not exceed a week; but

3. When the smallpox matter was inserted on the ninth day after the inoculation with cowpox, its action seemed to be wholly precluded.*

That is to say, for a time-until the influence of the vaccine fever had worn off. Some fancied that smallpox when inoculated with cowpox generated a hybrid pox that was more efficacious than either. There was occa

* On Vaccine Inoculation. By Robert Willan, M.D. London, 1806.

sionally some interaction of the diseases, as of a subdued activity in each, but generally they proceeded together unaffected, the cowpox maintaining its characteristics in the midst of a crop of smallpox.

One point of great significance in Woodville's experience was overlooked. He inoculated with cowpox in the Smallpox Hospital, and some of his patients there contracted smallpox, who certainly were not inoculated with smallpox, either accidentally or by design. The lesson of this experience was unperceived, and though it has been repeated again and again, is rarely acknowledged. Vaccination in presence of smallpox, or in an epidemic of smallpox, is often a means of inducing the disease it is intended to prevent. It lights the fire; and when the fire is lighted, it is said, "Ah! it must have been a-light before." When we have a mind for an excuse, our sophistry is usually equal to the requisition.

The New Inoculation, as it was called, grew in favour daily. Woodville and Pearson did the real work of publicity and promotion-Pearson especially. Within seven months, January to August, 1799, they performed 2000 inoculations. In the Philosophical Journal, August, 1799, Pearson observed

In Scotland the New Inoculation has not been less successful. Dr. Anderson, of Leith, informs me that he has inoculated above 80 persons; that Dr. Duncan has begun the practice in Edinburgh and that it has been introduced in Dundee, Paisley, and Dalkeith. Nor did Pearson limit his efforts to his native land. He wrote

In the course of the same year, 1799, I extended the dissemination of the vaccine matter to Germany, for the Princess Louisa at Berlin, to Hanover, Vienna, Geneva, Lisbon, Paris, and Boston, and into the British Army through Mr. Keats.

Jenner regarded much of this activity with a jealous eye: it did not sufficiently make for his glory. He was anxious, fretful, helpless. "It is impossible for me, singlehanded, to combat all my adversaries," was his whine. "I am beset on all sides with snarling fellows, and so ignorant withal that they know no more of the disease

they write about than the animals which generate it." In order to keep his name to the fore, he published a second pamphlet in the spring of 1799, in which are several details of biographical interest.

CHAPTER VI.

JENNER'S Further OBSERVATIONS.*

THIS pamphlet appears to have been produced with many pains and extraordinary apprehensions. Jenner wrote to Gardner, 7th March, 1799

Every sentence must be again revised and weighed in the nicest balance that human intellect can invent. The eyes of the philosophic and medical critic, prejudiced most bitterly against the hypothesis, will penetrate its inmost recesses, and discover the minutest flaw were it suffered to be present. Language I put out of the question: it is the matter I refer to.t

These words betray excitement for which there was no warrant; and when we turn to the treatise that was to be weighed sentence by sentence in the nicest of balances, it is clearly seen that its author was a weak-minded creature. It is little more than a gossip about Cowpox without advance upon the statements of the Inquiry. Indeed, he sets out with the admission

Although it has not been in my power to extend the Inquiry into the causes and effects of the Variola Vaccinæ much beyond its original limits, yet, perceiving that it is beginning to excite a general spirit of investigation, I think it is of importance, without delay, to communicate such facts as have since occurred, and to point out the fallacious sources from whence a disease resembling the true Variola Vaccinæ might arise, with the view of preventing those who may inoculate from producing a spurious disease; and further, to enforce the precaution suggested in the former Treatise on the subject, of subduing the inoculated pustule as soon as it has sufficiently produced its influence on the constitution. (P. 69.)

* Further Observations on the Variola Vaccine. By Edward Jenner, M.D., F.R.S. London, 1799. 4to pp. 73. Reprinted with the third edition of the Inquiry in 1801, to which edition my references apply. + Baron's Life of Jenner, vol. i. p. 322.