""Letter To Sir Henry Halford: Proposing A Method Of Inoculating The Small-Pox"" is a book written by R. Ferguson in 1825. In this book, the author proposes a new method for inoculating the smallpox, which was a deadly disease that plagued humanity for centuries. The book is addressed to Sir Henry Halford, who was a prominent physician and a member of the Royal Society. Ferguson's proposed method of inoculation involves using the cowpox virus, which...