The Letters
Period 3 - 1683-1685

editors: Robert Plot
and William Musgrave

While this was the shortest of the seven periods of van Leeuwenhoek's publication history, it was pivotal. The Royal Society was so successful, its members' research so broad and deep, that what was seen as one -- natural philosophy, what we now call science -- was becoming too complex.

The first great division was between the researchers who used lots of mathematics and those who didn't. Astronomy, from Copernicus, Brahe, Kepler, and Galileo to van Leeuwenhoek's contemporaries Edmond Halley, Christiaan Huygens, and Isaac Newton, used mathematics to "see", to make sense of their numerical data, which was basically all they had. Biology and botany "saw" more directly. Human researchers sought patterns with their eyes, not with numbers.

In London

Up through this period, the editors of Philosophical Transactions published articles, reviews, and letters of both types, what we'll call the physical sciences and the biological sciences. The editor after Oldenburg's death, Nehemiah Grew, was mostly a botanist. Robert Plot, who agreed to be editor after Hooke stopped Philosophical Collections, did research of both types. He was joined in his third year and volume by William Musgrave, a physician who wrote about human diseases.

In this three-year period, according to Cole, van Leeuwenhoek wrote 11 letters that were all eventually extracted and published in the Philosophical Transactions in 12 different articles.

the first two, January 22, and July 12, 1683, Robert Plot published in volume 13 of 1683 (along with the letter from January 1680 from period 2).

the next three -- September 17, 1683, December 28, 1683, and April 14, 1684 -- Plot published in volume 14 of 1684. A shorter extract from the letter of September 17, 1683, an entirely new translation with the figures reversed and missing one of them, was published in volume 17 by Richard Waller.

the next four -- July 25, 1684, January 5 and 23, 1685, and March 30, 1685 -- Plot and William Musgrave published in volume 15 of 1685.

the next two -- July 13 and October 12, 1685, were published by Richard Waller in volume 17 of 1693. (See period 5.)

These letters were addressed to the Royal Society, two in 1683 specifically to Society president Christopher Wren, and one the following year to Francis Aston as secretary.

What van Leeuwenhoek observed

These letters cover a wide range of observations:

In Delft

During this time, at his own expense, van Leeuwenhoek began to publish the complete versions of his letters in the original Dutch. As shown on the table, left, he started with four pamphlets whose titles all began Ondervindingen en Beschouwingen / Experiences and Considerations, all printed by Daniel van Gaesbeeck in Leiden in 1684. The first contained the letters of June 14 and November 12, 1680. Neither was ever published in Philosophical Transactions, but the second had been published in Hooke's Philosophical Collections.

The three other pamphlets' titles all began Ontledingen en Ontdekkingen / Analyses and Discoveries. They were printed by Cornelis Boutesteyn in 1685. Both Boutesteyn and van Gaesbeeck were in Leiden, just 12 miles up the Vliet canal from Delft, which did not have the university and thus large publishing industry that Leiden did.

In 1685, van Leeuwenhoek stepped up his self-publication program. He began publishing larger pamphlets and finally collected 25 letters from nine pamphlets to become the first of what turned out to be four self-published volumes of his letters. He retained the pagination from the original pamphlets, so four different letters begin on "page 1".

These 25 include all 11 from this time period.

Bibliographic note: Dobell includes the eight letters (#53-60) written in 1687 in the second self-published volume. Cole includes these eight letters in the first self-published volume.