Wrote Letter 51 of 1686-06-10 (AB 93) to Members of the Royal Society

June 10, 1686
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Leeuwenhoek's summary

From both editions of Cinnaber Naturalis and translated into Latin for all of the editions, some re-titled, of Anatomia Seu Interiora Rerum.

Ontledingen en Ontdekkingen, van het Karpok, Bupariti, Kaukin, ende Adamboe-Zaad, ende het begin van de Plant in the Cocos-Noot; van de Kuyt of Eyeren van de Garnaad, Kreeft, en Krabbe, ende van de ongeboorne Garnaad en Kreeft, ende derselver Voorttelinge, ende die overgebragt tot de Voorttelinge van de Zaden van eenige Boomen.

Dissections and discoveries of the capoc, Bupariti, "Kaukin", and Adamboe seed, and the beginning of the plant in the coconut; of the roe or eggs of shrimp, lobster, and crab and of unborn shrimp and lobster, and the reproduction of the same, and of the carry over to the reproduction of the seeds of some trees.

Kapok is also spelled capoc and is also called the silk cotton tree. According to Alle de Brieven / Collected Letters, Leeuwenhoek was mistaken calling his specimens Kaukin and Adamboe.

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 twelve quarto pages, written by a copyist and signed by Leeuwenhoek, is preserved at the Royal Society (MS. 1913. L 2. 4.).


The original drawings are preserved in the Royal Society's archives. The scans on the sidebars came from Opera Omnia, the 1722 fourth edition of Arcana Naturae Microscopiorum.

As seen on the left sidebar, two figures were labeled Fig. 6. In the text, Leeuwenhoek discussed them as one: "Fig. 6. is also the young plant, whose leaves have not been stretched out so much." Alle de Brieven / Collected Letters concluded "There should have been 24 figures."

In the text, Leeuwenhoek noted that someone else drew all of the figures. For example, at the beginning of the letter, he write about where he got the seeds he examined:

To this end I have caused two such exceptional Seeds to be drawn.

Of Fig. 10, he wrote, "This, too, has been drawn through a weak magnifying glass." A few pages later:

Fig: 12 and 13. is the pip or kernel of the Seed, which I have split open and separated into two parts, and had these drawn as large as seen with the naked eye. ... fig: 21, which I also had drawn, as large as the same appears to us in our naked eye.

Finally, when discussing the final two figures, of unborn shrimp, Leeuwenhoek wrote:

In order to place before Your Honours' eyes the makings of an unborn shrimp, I have taken several of the same from the eggs, and placed four of these before my microscope, and had a draughtsman (teijkenaar) come to my house, and instructed the same to follow the figure, as it appeared to him, as closely as possible, without my wanting to tell him what it was that he was drawing; the same said many a time, while he was drawing: I don't know what I am drawing, but it seems to me that it is a shrimp.