To C.H Parry, M.D.
My Dear Friend,
In the present age of scientific investigation, it is remarkable that a disease of so peculiar a nature as the Cow Pox, which has appeared in this and some of the neighbouring counties for such a series of years, should so long have escaped particular attention. Finding the prevailing notions on the subject, both among men of our profession and others, extremely vague and indeterminate, and conceiving that facts might appear at once both curious and useful, I have instituted as strict an inquiry into the causes and effects of this singular malady as local circumstances would admit.
The following pages are the result, which, from motives of the most affectionate regard, are dedicated to you, by
Your Sincere Friend,
June 21st, 1798
From the arm of this girl matter was taken and inserted April 12th into the arms of John Macklove one year and a half old...