Henry Oldenburg wrote Letter L-020 to Leeuwenhoek about his doubts about globules

January 3, 1675

Oldenburg wrote this letter on 24 December 1674 O.S. in London. It is known only by reference in another letter.

From Leeuwenhoek's defensive reply in Letter 9 of 1675-01-22, Oldenburg must have expressed his doubts about Leeuwenhoek's finding globules in so many of the things he examined. He still encouraged Leeuwenhoek and expressed his appreciation. He also passed along greetings from Thomas Willis. Oldenburg asked Leeuwenhoek to reexamime the optic nerve because Willis and others had made observations of an optic nerve that did not agree with Leeuwenhoek’s. Oldenburg also asked Leeuwenhoek to observe tobacco and tobacco seeds.


The manuscript is missing; this letter was never printed. It is not mentioned in Birch's History of the Royal Society of London.

Letter L-021 of 22 January 1675 to Henry Oldenburg:

Your very esteemed letter of the 24th of December has reached me in good order; from it I learned that my letter of the 4th and the drawing of the optic nerve reached you, and also the undeserved affection of Your Honour and of Mr. Willis and the other gentlemen amateurs pleased me extremely.

You have the goodness to recommend me to take care not to be deceived by my method of observation. ... I am not surprised that some do not agree with my discovery of particles (which I pretend to have discovered everywhere) ...

At your request I have again observed the optic nerve and found the same as I described it in my previous letter. ...

I was pleased to learn that Mr. Willis also was observing the optic nerve, and if this gentleman might disagree with my findings or make different observations, I shall be obliged to learn his views so that I may verify my own observations once more. ...

You write to me that others will have seen the spaces aforesaid in the optic nerves of larger animals, even without the microscope, i.e. with the naked eye. ...

You were so good as to ask me to observe tobacco and the seeds of tobacco.