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.
In this letter, L. discusses the miscroscopic structure of diamonds and rock crystal.
No Dutch manuscript known. The signed manuscript of the Latin translation is to be found in London, Royal Society, Early Letters, L.4.83, 12 quarto pages; 1 engraving.
The letter was read at the 20 December 1722 meeting of the Royal Society. Journal Book Original, vol. 12. Letter Book Original, 15.78.
The records of the Royal Society indicate that this letter was accompanied by a single engraving with 7 images (Royal Society, Letter Book Original, 15.78.1) and another engraving with figure 8 (Royal Society, Letter Book Original, 15.78.2). However, figures 1-9 are to be found on the plate with no. 374 of the Philosophical Transactions.
In keeping with the request of James Jurin in Letter 364 of 15 May 1722, Leeuwenhoek had this letter translated from Dutch into Latin, probably by Henrick van Rijn, before he signed and sent it. It was published in Philosophical Transactions in Latin, so no contemporary English translation was made.
