Jack and Jackey undergo smallpox variolation

His dated letter reported living “animalcules” in pepper water and water from different sources.

Leeuwenhoek sent his observations to Henry Oldenburg in London for discussion at the Royal Society.

The letter compared well, rain, sea and other waters through a microscope; identification of individual species came later.

The 9 October account became important to the later history of microbiology, although it was not yet a theory of infectious disease.

Historical accounts date Boylston’s first group to 26 June: his son Thomas and the enslaved Jack and Jackey were inoculated against smallpox.

Onesimus, enslaved by Cotton Mather, had earlier described an African inoculation method that shaped advocacy during the epidemic.

Boylston treated his own son and two people he enslaved, while Asian, African and Ottoman variolation practices long predated Boston’s experiment.

Jenner transferred material from milkmaid Sarah Nelmes’s cowpox lesion to the eight-year-old boy.

Sarah Nelmes supplied the cowpox material used in the experiment; she should be included in the account of the procedure.

The date marks Phipps’s cowpox inoculation, not the later challenge that tested whether he was protected.