Figures in Period 2

Leeuwenhoek published all of these letters and their figures in 1684, 1685, and 1686. The collected volume is sometimes known as Ontdeckte Onsigtbaar-heeden. The editors of Philosophical Transactions published 16 of them, marked with single asterisks on the table below. During its hiatus after the death of Henry Oldenburg, between 1679 and 1682, Hooke published five letters from this period in Philosophical Collections. The first four of them -- Letters 28, 33, 34, and 35 -- had 19 figures. Hooke published 18 of them, omitted only the figure of concentric circles that Leeuwenhoek used to illustrated how he calculated the quantity and size of the little animals that he was observing.

During Leeuwenhoek's lifetime, translations of his letters appeared excerpted and summarized in French, Dutch, and German. More letters from Period 2 were selected than from any other period. This is the period in which Leeuwenhoek, more confident after his election to the Royal Society, was breaking new ground with almost every letter. However, probably because of the expense and trouble of engraving new plates, few of the figures were reproduced.

• From 1682 to 1685, Otto Mencke published Philosophical Transactions' and Philosophical Collections' excerpts of five letters written between 1680 #33 and 1685 #45 in Acta Eruditorum. He published 26 of the 40 figures on newly engraved plates.

• In 1683, Monsieur l'Abbé de la Roque, editor of Journal des Sçavans, published French translations of the Philosophical Transactions excerpts of Letter 20 of May 15, 1677 and Letter 35 of March 3, 1682 in his short-lived Journal de médecine. Letter 20, written during Period 1, had no figures. Letter 35, however, had four of the six figures in Philosophical Transactions (of the 7 figures with Leeuwenhoek's manuscript).

• In 1684, Pierre Bayle published Letter 37 of January 22, 1683 and Letter 38 of July 16, 1683 along with one of their 12 figures in Nouvelles de la république des lettres.

• In 1686 and 1687, Jean Le Clerc published excerpts from seven of Leeuwenhoek's letters written between 1679 (#28) and 1686 (#48) in the first five volumes of Bibliothèque universelle. Of the 42 figures in the letters, Le Clerc published only the two dozen in Letter 29 of January 12, 1680.

• In 1715, Daniel Le Clerc (no relation to Jean?) published long passages from Letter 34 of November 4, 1681 and Letter 39 of September 17, 1683 about acne. Alle de Brieven / Collected Letters noted that Le Clerc included the six figures from this letter, but they are not in my scan of Historia naturalis. Letter 34 had 4 figures and Letter 39 had 10.

In the decades after Leeuwenhoek's death, translations of his letters appeared excerpted and summarized in French, Dutch, and German.

• In 1766, excerpts from 11 letters were were published in volumes II and VII of Collection Academique. Two of them, Letter 39 of September 17, 1683, and Letter 40 of December 28, 1683, both to Francis Aston, contained figures. Jean Berryat published 9 of the 10 in Letter 39 and 6 of the 11 in Letter 40.

• In 1779 and 1780, Nathanael Gottfried Leske published 15 of the 35 figures in four letters from Period 2 in Abhandlungen zur Naturgeschichte, Physik und Oekonomie: Letter 38 of July 16, 1683, Letter 39 of September 17, 1683, Letter 40 of December 28, 1683, and Letter 41 of April 14, 1684. The first was written to Christopher Wren and the other three to Francis Aston.

Figures in Works I

Bold - original drawings preserved at the Royal Society
* - letters and figures published in Philosophical Transactions
** - letters and figures published in Hooke's Philosophical Collections
^ - only 11 figures in the 1696 second edition published by Leeuwenhoek
^^ - only 13 of the 19 figures in Letter 46 are preserved at the Royal Society

Letters without figures:

Only Letter 36 of April 4, 1682 to Robert Hooke is without figures.