The Letters
Period 6 - 1715 -1719

editor: Edmond Halley

For this 6th period of van Leeuwenhoek's relationship with the Royal Society, Edmond Halley was once again the editor for volumes 29 and 30.

In London

Having matured, its founders dead or aging, the Royal Society entered what some see as a decline from its original vigor and rigor. In 1703, Sir Isaac Newton had become president, and his supporter Edmond Halley resumed the job of editor of Philosophical Transactions, which he had previously held for a few years two decades previously when he edited volume 16.

Over a period of five years, Halley dramatically slowed down the publication schedule and concentrated on articles about astronomy and the physical sciences, as he had with volume 16. Just as he had declined to publish van Leeuwenhoek's letters in volume 16 in the late 1680's, so he would again decline three decades later for volume 30.

Just as Halley as editor had published 13 of his own articles (and none of van Leeuwenhoek's) in volume 16, in period 6, he published nine of his own articles in volume 29 and five in volume 30.

In Delft

Starting with the letter of Nov 8, 1712, the next forty-six letters through Nov 7, 1717, van Leeuwenhoek published himself as the Send-Brieven / Epistles in 1718, including the two letters published in volumes 28 and 29 of Philosophical Transactions.

Thus, between 1712 and 1719, one of the most productive periods of his life, van Leeuwenhoek had only two articles published by Philosophical Transactions.

At the end of this phase, according to Cole, over two years from November 20, 1717, to January 1720, van Leeuwenhoek wrote no published letters. The other period when van Leeuwenhoek wrote no letters, the eighteen months from April 1, 1689, until September 18, 1691, Halley was also editor and not publishing van Leeuwenhoek. As another parallel, the 1689-91 letter gap came just after he published Tweede Vervolg / Second Continuation, and this 1717-20 letter gap came just after he published Send-Brieven / Epistles.

Then, when van Leeuwenhoek was 87, the Royal Society replaced Halley as editor with James Jurin. Over the final years of his life, what I call period 7, he sent another dozen letters to the Royal Society that were published in Philosophical Transactions alone.

Unfortunately, the 19-volume Alles de Briven / Collected Letters project has published only fifteen volumes, through July 1707, so the only English translations are half a dozen excerpts scattered (and not dated) through Hoole's Selected Letters.

Send-Brieven / Epistles

Van Leeuwenhoek wrote these 46 letters between 1712 and 1717 to a variety of people. He addressed about a fifth of them to the Royal Society in spite of the fact that editor Halley was showed not the slightest interest in publishing them.

In 1718, he collected the 46, numbered them in Latin (second column in table below), and published them himself in Dutch as the fourth and final volume of his collected letters. As with the other three, he had the letters translated into Latin and published in a separate and mostly parallel volume the following year.

Van Leeuwenhoek's Cabinet of Wonders

During van Leeuwenhoek's time, the Dutch mania for collecting extended into the middle class, including retail merchants like van Leeuwenhoek. We can assume that many of his friends and neighbors had their own modest collections, fueled by the things brought back by the ships of the VOC, Dutch East India Company. Delft had one of the VOC's few regional offices.

The collected things were called rariteiten, rare, strange things, curiosities. To describe his own microscopic collection, van Leeuwenhoek used the word wonderlyk, wonderful, marvelous. His collection was harder to display. On the other hand, because it had to be drawn and printed, his collection, the plates in Send-Brieven / Epistles, could spread far beyond his home or the trays near his workbench.

On the right and on other pages are van Leeuwenhoek's cabinet of wonders, a gallery of all the illustrations that accompany the Send-Brieven / Epistles. The plates are better than those that appear early in his career in Philosophical Transactions, no doubt because he could afford better draughtsmen and because he supervised the printing himself.

The table below lists all 46, along with the addressee and the number of figures, if any (right column). The letters are uniquely numbered, dated, and addressed, but none has a title provided by van Leeuwenhoek.

However, he preceded the text of each letter with an inhoudsopgave, a list of the topics. They are often long, several hundred words, and usually phrases rather than sentences.

In the table below, the Dutch title is the first substantive phrase from van Leeuwenhoek's inhoudsopgave. The dates are linked to that letter on the other pages of this web.

On the right, the six figures accompanying Letter I are preceded by two versions of van Leeuwenhoek's inhoudsopgave, in English (my translation) and in Dutch, my emphasis added throughout.