[141] Letter to James Moore, 4th April, 1809. Baron’s Life of Jenner, vol. ii. p. 126.
[CHAPTER XVIII.]
HORSEGREASE AS A SOURCE OF VACCINE.
In order to complete the account of Jenner’s awards and the adoption of Vaccination by Parliament, I have passed over several matters of interest and significance, which I shall now proceed to deal with, commencing with the tactics of our hero in relation to Horsegrease.
In his Inquiry, published in 1798, Jenner set forth Horsegrease as the origin of that form of Cowpox, which, when inoculated on the human subject, ensured life-long security from Smallpox. Many attempts were consequently made to produce pox on the teats of cows by inoculating them with Horsegrease, but in vain; and the possibility became discredited. Moreover, the notion of inoculation with Horsegrease, either immediately or through the cow, was disliked intensely. It was pronounced repulsive. Why virus from horses’ heels should be more repulsive than virus from cows’ teats was not explained; but, as we know, there is no accounting for tastes. Many who eat beef with relish would start with disgust from horse-flesh. A story is told of a Wesleyan who rebuked a sister for wearing feathers in her hat, and was sharply referred to the existence of flowers in her own. “Yes, sister dear,” was the cogent reply, “but we must draw the line somewhere, and it is drawn at feathers.” The line was drawn at Horsegrease, and the origin of Cowpox as asserted by Jenner and his country acquaintance was conveniently denied. Jenner was not slow to perceive how the wind of opinion was blowing, and let Horsegrease drop. He said not a word about it in his petition to Parliament in 1802, nor did he again advance it as a reason for consideration.
Now, why was this? Was it because he had ceased to believe that Cowpox originated in Horsegrease? Not at all! Why, then, did he not vindicate his opinion and confront vulgar prejudice? Simply because he had the wit to discern, that whilst he might get something out of the national purse for the Cowpox recipe, he could get nothing for the Horsegrease one. As Dr. Pearson observed, “The very name of Horsegrease was like to have wrecked the whole concern”—an observation that Dr. Mason Good confirms in saying, “The mere idea of using the matter of grease from the horse’s heel excited from the first so deep and extensive a disgust that Cowpox Inoculation had nearly fallen a sacrifice from the supposed union of the two diseases.”
It is not to be supposed that I am censuring Jenner as a tradesman.[142] If any of us had two patents for sale, we should be great fools if we declined to take £30,000 for one without the other, or suffered one to prejudice the other, or tried to inflict any doctrine about them upon the purchaser. It is for those who go to market to adapt themselves to the market, and remember that sellers were made for buyers, and not buyers for sellers. Since then the public were ready to pay for Cowpox, whilst they shuddered at Horsegrease, it was not for Jenner to force Horsegrease upon them.
Such is mercantile logic; and on its own conditions it is irrefragable; but it is not the custom to deal with Jenner as a tradesman, but as a man of science, and to range him with great discoverers, inventors, and benefactors of mankind; and here it is that I decidedly demur. What, I ask, did he discover? He did not discover that Cowpox prevented Smallpox: that was the dairy-maids’ faith. He did not discover that Horsegrease prevented Smallpox: that was the farriers’ faith. He did not discover that Horsegrease on milkers’ hands begot pox on cows’ teats: that was the farmers’ belief. He did not discover that inoculated virus could be conveyed from arm to arm: that was an existing practice. What then did he discover? He discovered nothing. He did no more than take the vulgar opinion of his neighbourhood to the London market. He made a few perfunctory experiments by way of confirmation, advertised them in a book, and by good or ill luck the notion was caught up, and worked to practical issues, chiefly by Pearson, who thereby incurred the full malignity of Jenner’s jealousy.
The distinction between a man of science and a tradesman is this, that the mind of the one is set on the extraction of truth and the other on the extraction of profit. The man of science does not inquire what the public may be pleased to know and pay for, but he ascertains and defines what is fact, and leaves the public to adjust themselves thereto as they may find convenient. If they recognise the truth communicated, it is well for them; if they dislike or deny the truth, it is ill for them; but well or ill, the man of science is the disinterested expositor of what he knows to be true; not unfrequently, when his revelation vitally affronts popular prejudice, realising the blessing of those who are persecuted for righteousness’ sake.
What therefore I maintain concerning Jenner is, that the truth (as we may presume he regarded it) he did not fully reveal; that what he did reveal, he suffered to be derided and denied; that he was content to take credit for so much of it as was marketable; whilst his private conviction about Horsegrease remained unaffected, not only in theory, but in deliberate practice.