JENNER. 263 a young countrywoman applied for advice ; the subject of small-pox was casually mentioned in her presence ; she immediately remarked, " I cannot take that disease, for I have had cow-pox." This was a popular notion in his district, but it now fixed his attention, and grew with his growth. It appears that, in Dorsetshire, a pustular eruption, derived from infection, and chiefly showing itself on the hands of milkers who had milked cows similarly disordered, attracted attention about forty or fifty years ago. It had been found to secure persons from the small-pox. Numerous examples are said to have been communicated to Sir George Baker, who had been, not long before, engaged in a very troublesome, though honourable and successful, controversy respecting the endemial colic of Devonshire, and was probably unwilling to break another lance. In one of Jenner's note- books, of 1799, we find the following anecdote. — " I know of no direct allusion to the disease in any ancient wiiter, yet the following seems not very distantly to bear upon it. When the Duchess of Cleveland was taunted by her companions, Moll Davis (Lady Mary Davis) and others, that she might soon have to deplore the loss of that beauty which was then her boast, the small-pox at that time raging in London : she made a reply to this effect, — that she had no fear about the matter, for she had had a disorder which would prevent her from ever catching the small-pox. This was lately communicated by a gentleman, in this county, but unfortunately he could not recollect from what author he gained this intelligence." Jenner had frequently witnessed the ravages of