Constantijn Huygens wrote Letter L-044 to Leeuwenhoek about his son Christiaan's translating Letter L-040

October 31, 1676

This letter is known only by reference in L.’s reply.

In this letter, Constantijn Huygens responds to the copy of L.’s October 1676 letter to Henry Oldenburg about little animals in infusoria that he is returning. Huygens is pleased by L.’s observation but wonders why he has structured it like a journal. He also tells L. that his son is going to translate the letter into French and send it to Paris.

Huygens’s previous letter to Leeuwenhoek is Letter L-007 of 11 April 1674. Leeuwenhoek responded with Letter 7 L-009 of 24 April 1674 about blood, bones, teeth, and salt crystals.

Huygens replied with the present letter, with which he returned a copy of Leeuwenhoek’s Letter L-040 of 9 October 1676 about his series of experiments observing little animals in infusions. That implies another lost letter, but Huygens could have received the copy of Letter L-040 during one of his visits to L.’s house in Delft. He must also have asked why L. structured the letter as a narrative of his observations over six months.

Even though Huygens was returning Letter L-040, in L.’s response, Letter L-045 of 7 November 1676, he summarizes its contents. The end of Letter L-045 seems to imply that Huygens’s son Christiaan is going to send his translation of Letter L-040 to Paris. Instead, Christiaan translated the much shorter Letter L-045, ending it with a comment implying that he had seen the little animals himself through Leeuwenhoek’s microscope. For details, see an exchange of letters between Christiaan Huygens and Leeuwenhoek: Letter L-050 of 9 February 1677 and Letter L-051 to Huygens of 15 February 1677. For the translation of Letter L-045, see Huygens, Oeuvres completes, vol. VIII, p. 22.

Constantijn Huygens’s next letter to Leeuwenhoek is Letter L-062 of 8 December 1677, within Letter L-349 of 17 December 1698.


Letter L-045 of 7 November 1676 to Constantijn Huygens

Your welcome letter dated 31st ultimo and the copy of my missive duly came to hand. I was glad to see that you were pleased with the work I have done in discovering numerous living creatures in infusions of spices. I have couched my observations in the form of a journal, merely that they be better credited in England and elsewhere, the more so because the Secretary, Mr. Oldenburg, wrote to tell me some time ago that there actually are learned gentlemen in Paris and elsewhere who do not believe what I saw ...

Your Excellency tells me in his letter that your son not only intends to send my observations to Paris, but even to assist me by translating them into good French. I am very grateful to you for this, and am only afraid lest my frequent descriptions should tire your son. Please offer my humble greetings to your son.