Dr. Croft likewise told Pearson—
That in Staffordshire to his knowledge, the fact had been long known of the Cowpox, which prevails in that county, affording an exemption of the human subjects from the Smallpox. (P. 35.)
Nor did what was so widely believed escape mention in medical literature. Thus Dr. Beddoes, in Queries concerning Inoculation, had written in 1795—
I have learnt from my own observation, and the testimony of some old practitioners, that susceptibility to the Smallpox is destroyed by the Cowpox, which is a malady more unpleasant than dangerous.
And Dr. Adams, in his treatise on Morbid Poisons, 1795, observed—
Cowpox is a disease well known to the dairy-farmers in Gloucestershire. What is extraordinary, as far as facts have hitherto been ascertained, a person infected with Cowpox is rendered insensible to the variolous poison.
And Dr. Woodville in his History of Inoculation, 1796, argued—
It has been conjectured that the Smallpox might have been derived from some disease of brute animals; and, if it be true that the mange affecting dogs, can communicate a species of itch to man; or that a person, having received a certain disorder from handling the teats of cows, is thereby rendered insensible to variolous infection ever afterwards—then, indeed, the conjecture is not improbable.
The belief, moreover, that Cowpox was good against Smallpox, had tempted several to court the disease. The Rev. Herman Drewe wrote to Pearson of himself and Mr. Bragge, surgeon, Axminster, 5th July, 1798—