1683-84: Contradicted by many

1683-1684: "I shall be contradicted by many all over the world."

While this was the shortest of the seven periods of 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.

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 two-year period, Leeuwenhoek wrote 12 letters, 11 of them to the Royal Society. He addressed two in 1683 to Christopher Wren, four to Francis Aston, and five to the members of the Royal Society in general.  All were eventually extracted and published in the Philosophical Transactions in 12 different articles.

  • the first two, January 22, 1683 (AB 70), and July 16, 1683 (AB 72), were addressed to Wren. Robert Plot published them in volume 13 of 1683 along with the letter from January 1680 from period 2.
  • the next three -- September 17, 1683 (AB 76), December 28, 1683 (AB 79), and April 14, 1684 (AB 80) -- were addressed to Aston. Plot published the 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.
  • of final one, July 25, 1684 (AB 81), was addressed to Aston. William Musgrave published it in volume 15 of 1685.

Interspersed with these letters, Leeuwenhoek addressed six of the period's 19 letters to Anthonie Heinsius. Cole was not aware of their existence when he compiled his list in 1937. Their first publication was in Alles de Brieven / Collected Letters volume 4 in 1952.