📅 9 October 1676
His dated letter reported living “animalcules” in pepper water and water from different sources.
📅 9 October 1676
Leeuwenhoek sent his observations to Henry Oldenburg in London for discussion at the Royal Society.
📅 9 October 1676
The letter compared well, rain, sea and other waters through a microscope; identification of individual species came later.
📅 9 October 1676
The 9 October account became important to the later history of microbiology, although it was not yet a theory of infectious disease.
