Wrote Letter L-136 of 1683-09-30 to Anthonie Heinsius, a note accompanying a copy of Letter L-135
Date:
September 30, 1683
Text of the letter in the original Dutch and in English translation from Alle de Brieven. The Collected Letters at the DBNL - De Digitale Bibliotheek voor de Nederlandse Letteren.
The original manuscript on two quarto pages, written and signed by Leeuwenhoek, is preserved at the Rijksarchief (National Archive) in Den Haag (Inv. No. 13). The letter was not published during his lifetime.
Leeuwenhoek wrote this very short cover letter to his old friend enclosing "the last observations that I have forwarded to the Royal Society", probably Letter L-135 of 17 September 1683, to Francis Aston.