1686: Royal Society

Events at the Royal Society in the first half of 1686 caused a major shift in Leeuwenhoek's career.

On January 27, 1686, the Royal Society elected Edmond Halley as clerk. Leeuwenhoek would not have another letter published in Philosophical Transactions until Halley's stint as clerk and editor was over.

March 2, 1686: editor Edmond Halley wrote a letter to Leeuwenhoek
May 19, 1686: The Royal Society decided to send a gift to Leeuwenhoek
May 25, 1686: editor Edmond Halley wrote a letter to Leeuwenhoek
June 16, 1686: The Royal Society officers declared their satisfaction with election of Edmond Halley

At some point during the year, Leeuwenhoek sat for his portrait. He also bought a burial section in the Oude Kerk. Where had his first wife and four deceased infants been buried?

January 1, 1686: Sat for his oil portrait by artist Johannes Verkolje (1650-1693)

June 8, 1686: Bought a burial section in the Oude Kerk

In the first half of the year, he studied and reported on

properties of cinnabar and gunpowder
structure of bone, tree bark, skin, and scales; sweat
gall nuts
seeds of capoc and coconut; roe or eggs of shrimp, lobster, and crab 
structure of wood

By September 7, 1686, he was examining silkworm eggs. He reported on his obversations in Letter 56 of July 11, 1687, (AB 101) to Members of the Royal Society

Not quite realizing the import of Halley's selection as editor and perhaps under a false impression caused by the friendly tone of Halley's letters in March and May along with a gift from the Royal Society, Leeuwenhoek continued addressing letters of scientific observations to the gentlemen in London. Of the five, three of them were published in 1693 and 1694 when Hans Sloane succeeded Halley.

January 22, 1686: Wrote Letter 48 of 1686-01-22 (AB 89) to Members of the Royal Society

April 2, 1686: Wrote Letter 49 of 1686-04-02 (AB 90) to Members of the Royal Society
May 14, 1686: Wrote letter of 1686-05-14 (AB 91) to Antonio Magliabechi
May 14, 1686: Wrote Letter 50 of 1686-05-14 (AB 92) to Members of the Royal Society

June 10, 1686: Wrote Letter 51 of 1686-06-10 (AB 93) to Members of the Royal Society

July 10, 1686: Wrote Letter 52 of 1686-07-10 (AB 94) to Members of the Royal Society

September 10, 1686: Wrote letter of 1686-09-10 (AB 95) to Daniël Papenbroek
October 30, 1686: Wrote letter of 1686-10-30 (AB 96) to Antonio Magliabechi

Leeuwenhoek and Cornelis Boutsteyn continued publishing letters. Two volumes appeared at some time during the year. Letter 36, the latest in Levende Dierkens, had been written in 1682, so it was probably printed first. Letter 52, the latest in Cinnaber Naturalis, was written in July of 1686, so the volume containing it could not have been printed until late summer or fall.

January 1, 1686: Published Levende Dierkens (Living Animals), Letters 28 - 31, 34 - 36
January 1, 1686: Published Cinnaber Naturalis (Natural Cinnabar), Letters 48 - 52