Leeuwenhoek did not publish any letters after 1718 in book form with his own summaries. The summary below comes from Alle de Brieven / Collected Letters.
Leeuwenhoek thanks the Royal Society for sending numbers of Philosophical Transactions. He examines a callus from his own foot and from the hands of a bricklayer, a carpenter, and a farmer and concludes that all food that is prepared by hand also contains little pieces of skin.
Signed autograph letter. The manuscript is to be found in London, Royal Society, Early Letters L.4.81; 8 quarto pages, 1 engraving.
A contemporary English translation of the letter by John Chamberlayne is to be found in London, Royal Society, Early Letters L.4.82; 7 pages.
The letter was read during the 15 November 1722 meeting of the Royal Society; Royal Society, Journal Book Original, vol. 13; Letter Book Original, 15.77.
No original drawings now exist. The letter came with three figures on a single engraving. Figures 1-3 can be found as Figs. VI-VIII on the plate at No. 373 of the Philosophical Transactions
