Wrote Letter 40 of 1683-12-28 (AB 79) to Francis Aston

December 28, 1683
Standard reference information
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Text of the letter in the original Dutch and in English translation from Alle de Brieven / The Collected Letters at the DBNL - De Digitale Bibliotheek voor de Nederlandse Letteren.

The original manuscript on twenty-four quarto pages, written and signed by Leeuwenhoek, is preserved at the Royal Society (MS. 1899. L 1. 70).


The original drawings are lost. The Dutch and Latin editions that Leeuwenhoek published used the same plates placed throughout the text where each figure was discussed. The scans on the left sidebar came from the 1695 first edition of Arcana Naturae Detecta.

In the text, Leeuwenhoek noted that he drew Fig. 3 through Fig. 11. The first two were well within his skills, so he probably drew them, too.

I have drawn the outline of one of these blood-vessels in fig. 3 ABCDEFG, this circumference not being so big but that a grain of sand could cover it. This vessel was about as thick as a twenty-fifth part of a hair taken from our head. From its inside there sprouted again many little vessels which (as far as the eye would reach) all united. Of these I have indicated only four branches as BLE and CLF in fig. 3; and HIK in fig. 4. is a small veinlet, which although I have drawn it from one side.