ness he lost the scent, and allowed himself to be deceived; and not only deceived, but to become a prime mover in the deception of the world. Jenner felt the difficulty and replied

CHELTENHAM, 27th September, 1798.

MY DEAR SIR,-You may be assured that a person may be repeatedly affected, both locally and generally, by the Cowpox, two instances of which I have adduced, and have many more in my recollection; but, nevertheless, I have some reason to suspect that my discriminations have not been, till lately, sufficiently nice. Certain it is, that the skin is always subject to the ulcerative effects of the virus; but whether the constitution can repeatedly feel the primary effects of it, I have experiments in view to determine. (P. 99.)

This passage is commended to those who hold with Mr. John Simon that Jenner delivered to the world "a Master-piece of Medical Induction," the fruit of thirty years of incessant thought, watching and experiment. It is plain that in 1798 the very elements of the problem were by him undetermined, and the most obvious objections unforeseen and unconsidered.

Pearson's strongest opposition was reserved for the asserted origin of Cowpox in Horsegrease. He said—

It has no better support than the coincidence in some instances of the two diseases in the same farm in which the same servants are employed among the Horses and Cows.

I have found that in many farms the Cowpox breaks out although no new-comer has been introduced to the herd; although the milkers do not come in contact with the Horses; although there are no greased Horses; and even although there are no Horses kept on the farm.

It appears that the Cowpox does not break out under the most favourable circumstances, if it be occasioned by the Grease. "I have had," writes Sir Isaac Pennington, Cambridge, 14th September, 1798, "Dr. Jenner's book some weeks, and the particulars stated in it are really astonishing. I have made inquiries upon the subject at Cottenham and Willingham, in which two parishes 3000 milch Cows are kept; also a great many Horses of the roughlegged cart kind (much liable to the scratches or grease) half the parishes being under the plough, and the men much employed in milking. But I cannot find that any pustulous eruptions on the teats of the Cows, or on the hands of the milkers, have ever been heard of." (P. 82.)

In the opening of his Inquiry, Pearson was good

enough to say of Jenner, "I would not pluck a sprig of laurel from the wreath that decorates his brow"; but, disputing the origin of genuine Cowpox in Horsegrease, he might have asked himself, what sprig of laurel he had left. That Cowpox originated in Horsegrease was not Jenner's discovery. As Pearson ascertained in the London milk farms, "There was such a notion entertained in several parts of the country, whatever might be its foundation." (P. 86.) But the definition of Horsegrease Cowpox as the form of Cowpox that justified the faith of the country-folk in the power of the disease to avert Smallpox, was Jenner's solitary distinction-the principle and motive of his Inquiry, which, to prove fallacious, was to extinguish his title to regard. Cowpox apart from Horsegrease was clearly taught by Jenner to have no influence on the constitution, and to be attended with no erysipelas. "Let me call your attention," he wrote to Pearson, 27th September, 1798, "to a similarity between the Smallpox and the Cowpox when inoculated. The symptoms of absorption first disturb the system, and, secondly, the system feels the consequences of the local sores. Exactly so with the Cowpox; and as the Cowpox inflammation is always of the erysipelatous kind, when it spreads over the skin to any great extent, it produces symptoms not unlike the confluent Smallpox." (P. 100.)

Pearson foresaw that if the principle of inoculation with Cowpox were established it would lead to other applications

The Cow Poison appears to alter the human constitution, so as to render it insusceptible of a different morbific poison, namely, the variolous in producing the Smallpox. This fact is, I believe, quite a novelty in physiology and pathology: it indicates a new principle in the mode of prophylactic practice. And we now see a principle upon which diseases from various other morbific poisons may possibly be prevented from taking place, such as the Measles, Ulcerous Sore Throat, Hooping Cough, Syphilis, etc., namely, in consequence of destroying the excitability of the constitution to such poisons by the agency of different, and perhaps less hurtful ones. Whether the Cowpox preserves the constitution from other morbific poisons, besides the variolous, is an undecided question. (P. 79.)

Like Jenner, he also recognised in Cowpox a counterirritant a safe sort of fever that might be used to drive off other diseases

If it be true that the same constitution is liable to undergo repeatedly the Cowpox, to which distemper no one has fallen a victim, practitioners may avail themselves of this means of exciting an innocent fever as a remedy of various disorders; it being a truth, admitted by men of experience, that fevers are occasionally efficacious remedies, especially for inveterate chronic maladies, such as Epilepsy, Hysteria, Insanity, St. Vitus's Dance, Tetanus, skin deformities and diseases, etc. (P. 81.)

Nor was the notion without warrant, for Smallpox itself was credited with a double action as a generator and exterminator of disease

A disposition to certain diseases, and even diseases themselves, are not rarely brought on by the Smallpox; but sometimes also dispositions to diseases, and diseases themselves of the most inveterate kind are removed by the Smallpox. (P. 77.)

In one respect, Jenner showed himself superior to Pearson, namely, in offering some explanation of Cowpox. Pearson accepted the disease on the rural terms-as an eruption on Cows attended with no serious illness. If in any way such Pox was equivalent to Smallpox, it was inexplicable that it should be limited to the udder and teats of milch cattle, and that males, and females not in milk, should be exempt from infection. A disease so unique wanted accounting for; but Pearson made no attempt to account for it, nor gave any sign that he apprehended the difficulty. Jenner, on the other hand, accounted for Pox on the Cow by referring it to infection from the Horse conveyed by the milkers, which explanation Pearson rejected. But in giving Jenner credit for so much, let it not be for over much. Whilst he ascribed Cowpox to a credible cause, he did not recognise his advantage and summon gainsayers to explain how Cowpox, as described by them, could exist without Bullpox. On the contrary, as we shall see, Jenner submitted to be silenced on this point for reasons far from creditable.

CHAPTER V.

WOODVILLE, PEARSON AND JENNER.

ANOTHER early and earnest examiner of Jenner's Inquiry was Dr. William Woodville, physician to the London Smallpox and Inoculation Hospital. He was a Cumberland man, born at Cockermouth, 1752; a member of the Society of Friends. An ardent botanist, he turned two acres of the ground around the Hospital at King's Cross into a botanic garden, which he maintained at his own expense. He died of a chronic pulmonary complaint in 1805, and in his last illness had himself removed from his house in Ely Place to the Hospital for the sake of the garden and the country air.

Woodville was eager to try cowpox, but Jenner had no supply, nor could any be had elsewhere. He therefore resorted to horsegrease, but could make nothing of it. In his own words

Conceiving that the distemper might be produced by inoculating the nipples of Cows with the matter of the grease of Horses, I proceeded to try whether the Cowpox could be actually excited in this manner. Numerous experiments were accordingly made upon different Cows with the matter of grease, taken in the various stages of that disease, but without producing the desired effect.

Neither were inoculations with this matter, nor with several other morbid secretions in the Horse, productive of any effects upon the human subject.*

Thrice in person did Woodville submit to inoculation with horsegrease, but in vain. Others in London and elsewhere attempted to raise pox on cows in the same way without result save malediction on Jenner for originating such a troublesome quest.

Thus closed 1798 with many anxious to try the new prescription whenever there was a chance. Early in the new year, there was a cry in London, 'Tis found! 'tis found! In Harrison's dairy, Gray's Inn Road, close by the

* Reports of a Series of Inoculations for the Variola Vaccina or Cowpox. London, 1799.

Smallpox Hospital, cowpox was discovered, and thither hastened Woodville, Pearson, Sir Joseph Banks, Sir William Watson, Dr. Garthshore, Dr. Willan, and other medical men; and in their presence, on 19th January, Woodville inoculated six patients with the pox.* The eruptions on the cows' teats were diligently compared with the description and plates in Jenner's Inquiry, and pronounced identical. Four-fifths of the 200 cows in the dairy became affected, those not in milk escaping the disease; likewise some of the milkers, the first being Sarah Rice, who had undergone smallpox in childhooda proof that smallpox did not prevent cowpox. "At the same time," wrote Dr. Pearson, "I received the agreeable intelligence that the disease was also raging in the largest stock of cows on the New Road, near Paddington, to which no one could gain admittance but myself."

With cowpox thus provided in abundance, Pearson and Woodville set to work-Woodville at his Hospital, and Pearson in private practice. Be it observed, however, that this London cowpox was not Jenner's cowpox. It was not horsegrease cowpox, but the variety stigmatised by Jenner as spurious. How Pearson and Woodville pressed forward with their enterprise appears from the following letter, enclosing cowpox threads, sent by Pearson to two hundred medical practitioners throughout the United Kingdom

LEICESTER SQUARE, 12th March, 1799.

Sir, I hope you will pardon me for taking the liberty to inform you (by way of additional evidence to the testimonies I have published on the subject of the Cowpox) that upwards of 160 patients, from two weeks to forty years of age, principally infants, have been inoculated since the 20th January last by Dr. Woodville and myself, separately.

Not one mortal case has occurred.

Not one of the patients has been dangerously ill. . .

None of the patients, namely above 60, inoculated with the Smallpox, subsequently to the Vaccine Disease, took the infection.

...

In many of the cases eruptions of the body appeared, some of which could not be distinguished from the Smallpox.

* J. C. Wachsel in London Medical Repository, 1819, p. 257.