Hans Sloane wrote Letter L-460 of 4 November 1707 on behalf of the Royal Society about recent letters and as cover for an enclosure of a "hairy substance"
This letter is known only by reference in Leeuwenhoek’s reply. The date is New Style, which was eleven days ahead of the Old Style date of 24 October 1707 used by the Royal Society in London.
In this letter, the Royal Society tells Leeuwenhoek that two recent letters will be printed and that the figures that should have accompanied an earlier letter are missing. Also enclosed is part of a hairy substance for L. to investigate.
The letter was most likely written by Hans Sloane as second secretary of the Society and editor of Philosophical Transactions.
The letters that Leeuwenhoek refers to as having written to Venetian envoy Francesco Cornaro (also Corner), Letter L-441 of 18 December 1705, and Florentine librarian Antonio Magliabechi, Letter L-436 of 12 March 1705, were both published in Philosophical Transactions, vol. 25, no. 311. They are discussed in Letter L-461 of 22 November 1707.
The “learned gentleman” is James Yonge (1647-1721).
Letter 273 L-461 of 22 November 1707 to the Royal Society
I saw in your kind letter of the 24th of October last that my extracts from my letters written to Messrs Cornaro and Magliabechi were to be printed in the next Transactions, and that the figures of my letter about the intestine were missing; enclosed I am sending them again. I also learned that you were satisfied with the letters I sent, which I was pleased to hear.
Enclosed with the said letter sent to me was a small part of a hairy substance, discharged by a woman of fifty years or older, who had an ulcer in her kidney after she had been administered a dose of Spanish fly, which substance had been sent to you by a learned gentleman.
