Cowpox children. In 1796, British medical practitioner Edward Jenner tested the theory that cowpox could protect someone from being infected by smallpox. Although cowpox originates on the udder of cows, Jenner took his sample from a milkmaid, Sarah Nelmes. Jenner extracted the pus of one of the lesions formed by cowpox on Nelmes to another individual who never had smallpox, James Phipps. He eventually developed a scab and fever that was manageable. Approximately six weeks later, Jenner then introduced an active sample of the smallpox virus into Phipps to test the theory. After being observed for an extended amount of time,
Henry Jenner of the language used in West Cornwall in the 18th century, although his pupil Robert Morton Nance would later steer the language revival towards mediaeval Cornish. At a time when many people thought the Cornish language had died Jenner observed In 2010, Michael Everson published a new edition entitled "Henry Jenner's Handbook of the Cornish Language", which contains modern IPA phonetic transcriptions to make clear to modern readers what phonology Jenner was recommending. The book also contains three essays written by Jenner thirty years prior to the 1904 publication, as well as some examples of a number of Christmas and