1679: I take courage once more
1679
The following year, 1679, finishing volume 12, Grew published in number 142, as one article, excerpts about human sperm from three Leeuwenhoek letters: November 1677 (AB 35 from Period 1), March 1678 (AB 38), and (another excerpt from) May 31, 1678 (AB 39). It was translated into Latin because it discussed human reproduction.
During 1679, Leeuwenhoek wrote 12 letters, including Letter 27 of February 21, 1679 (AB 42) to Nehemiah Grew, which was the last numbered letter that he did not self-publish. The next, Letter 28 of April 25, 1679 (AB 43), also to Grew, was the first-written of his self-published letters, though not the first one to be self-published. The one after that came in the following year, Letter 29 of January 12, 1680 (AB 43), to Robert Hooke.
Between Letters 28 and 29, we have ten letters,
February 21, 1679
Wrote Letter 27 of 1679-02-21 (AB 42) to Nehemiah Grew
April 1, 1679 cousin Maerten Huijchs Leeuwenhoek appointed tax master
April 25, 1679 Wrote Letter 28 of 1679-04-25 (AB 43) to Nehemiah Grew
April 27, 1679 Wrote letter of 1679-04-27 (AB 44) to Constantijn Huygens
May 11, 1679 Wrote letter of 1679-05-11 (AB 45) to Lambert van Velthuysen
May 15, 1679 Wrote letter of 1679-05-15 (AB 46) to Christiaan Huygens
May 20, 1679 Wrote letter of 1679-05-20 (AB 47) to Constantijn Huygens
June 13, 1679 Wrote letter of 1679-06-13 (AB 49) to Lambert van Velthuysen
June 13, 1679 Wrote letter of 1679-06-13 (AB 48) to Nehemiah Grew
July 11, 1679 Wrote letter of 1679-07-11 (AB 50) to Lambert van Velthuysen
August 15, 1679 Appointed city inspector of imported and exported liquids / wine gauger
August 25, 1679 Called "an illiterate, but ingenious man"
October 13, 1679 Wrote letter of 1679-10-13 (AB 51) to Robert Hooke
October 30, 1679 cousin Pieter Abrahams Hogenhouck buried
November 14, 1679 Wrote letter of 1679-11-14 (AB 52) to Lambert van Velthuysen
November 20, 1679 Wrote letter of 1679-11-20 (AB 53) to Robert Hooke