Hans Sloane wrote Letter L-284 of 17 February 1696 on behalf of the Royal Society to encourage Leeuwenhoek
This letter is known only by reference in another letter.
Someone from the Royal Society writes a courteous and encouraging letter to Leeuwenhoek that includes a reference to a letter that Leeuwenhoek never received.
The date is New Style, which was ten days ahead of the Old Style date of 7 February 1696 used by the letter writer in London.
Through 1694, Richard Waller was the Royal Society secretary designated to correspond with Leeuwenhoek. Beginning with Letter L-311 of 18 December 1696, Hans Sloane, elected second secretary of the Society in November 1693, assumed that responsibility. Thus, the present letter was probably written by him. If so, it is the beginning of their exchange of letters.
Leeuwenhoek’s reference to “another letter to me a few months ago” and, at the end of the letter, to “your very welcome letters” indicates yet another lost letter because the previous known letter from someone at the Royal Society to Leeuwenhoek was sent two years earlier, Letter L-243 of 2 May 1694, dated 22 April 1694 O.S., from Richard Waller.
Letter L-295 of 10 July 1696 to the Royal Society
I have duly received your very polite and pleasant letter of the 7th of February 1695/6, in which I saw the very polite expressions and encouragement used by you to communicate further discoveries of the secrets [of nature], and also that you had written another letter to me a few months ago. […]
Dear sirs, I should have answered your very welcome letters sooner if I had not intended to dissect the eels several times and also to enclose a print of the said figures.
