Wrote Letter L-060 of 1677-11-09 to William Brouncker about sperm and their movements in fresh human semen

November 9, 1677
Standard reference information
Leeuwenhoek's number: 
Collected Letters number: 
Collected Letters volume: 
2 and 20

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 is not preserved at the Royal Society.

An excerpt was published in Philosophical Transactions, vol. 12, no. 142, pp. 1040-43, dated 28 February 1679. See Publication history below. It was followed by a Latin response on p. 1043 from the "author", presumably editor Nehemiah Grew, that invited Leeuwenhoek to observe sperm in other animals. The article continued with excerpts about sperm from two more letters, Letter L-070 of 18 March 1678 on p. 1044, and Letter L-073 of 31 May 1678 on pp. 1045-46.

Leeuwenhoek wrote this letter, sent in Latin translation, to William Brouncker about sperm and their movements in fresh human semen, the "vessels" in semen and their supposed function, and his discovery of crystals in semen. It is the first detailed description, but it indicates no understanding of its function. In it, Leeuwenhoek mentions the role of both Theordore Craanen and Johan Ham.

Twenty years later, he quoted an excerpt from this letter in Dutch when he wrote to Harman van Zoelen to defend himself against Nicholas Hartsoeker.