Wrote Letter L-067 of 1678-01-14 to Robert Hooke about human blood, blood transfusions, flea larvae, and little animals in pepper water
Text of the letter in the original Dutch and in English translation from Alle de Brieven. The Collected Letters at the DBNL - De Digitale Bibliotheek voor de Nederlandse Letteren
The original manuscript on five folio pages, written and signed by Leeuwenhoek, is preserved at the Royal Society (MS. 1881. L 1. 52). On the ooutside, Leeuwenhoek wrote, "To Mr. Robert Hooke / Secretary of the Royal / Society at Gresham College. In London." Someone in London added, "Mr. Leeuwenhouks Letter to RH. / Jan: 14. 1677/8. Sn."
Leeuwenhoek wrote this letter to Robert Hooke about blood, milk, fleas, de Graaf's transfusions, and microorganisms in pepper infusions. Hooke published the letter in Microscopium in early 1678, followed by a short discussion of Hooke's own efforts at lensmaking.