Benedictus Haan wrote to Leeuwenhoek agreeing with him against George Garden about the female ovary

February 28, 1694

This letter is known only by its inclusion in Leeuwenhoek's letter of 1694-03-19 to the members of the Royal Society. Text of the letter in Alle de Brieven / The Collected Letters at the DBNL - De Digitale Bibliotheek voor de Nederlandse Letteren. He included it because it supported his argument against George Garden earlier in the letter.

Benedictus Haan was the Lutheran pastor in Delft from 1675 to 1695, when he moved to Amsterdam, where he died in 1702. In 1677, he was one of the people who wrote to the Royal Society attesting that they saw thousands of little animals in Leeuwenhoek's infusions.

In this letter, he greeted Leeuwenhoek as Mijn Heer en zeer waarde Vrind (Dear Sir and highly valued friend):

I ... am astonished that there are still found People who uphold the insane opinion about the Female Ovary. Here in Amsterdam I have already made various people change their minds through the things I have seen and heard from you, etc. ...

I consider the rest of your reply to Mr. Garden so well-founded that I do not see how unprejudiced people can contradict it.


the manuscripts of both letters, Leeuwenhoek's and Haan's, are lost.