Francesco Corner wrote Letter L-443 to thank Leeuwenhoek for Letter L-441 about pearls
This letter is known only by reference in another letter.
In this thank-you letter, Corner tells Leeuwenhoek that he is satisfied by his long letter about pearls.
The Italian diplomat Corner visited Leeuwenhoek some time between early September to mid-November 1705 while he waited for a favourable wind for the crossing to England, where he would assume his post as envoy to the British court. He could have sent another lost letter to Leeuwenhoek along with the coats of arms.
Leeuwenhoek's letter to Corner about pearls is Letter L-441 of 18 December 1705, Collected Letters and Corner’s thank-you letter was written presumably shortly thereafter. This is the only known correspondence between them.
Letter L-452 of 17 May 1707 to John Chamberlayne
Now as the Bezoar Stone is of no use in physick so neither are pearls as I have writ at large to his Excellency Francisco Cornaro Envoy, from ye Republick of Venice to her Majesty of Great Brittain. This gentleman did me the honour one afternoon to come to me and see my observations wherein he took much pleasure, & understanding that I never wou’d accept of any gifts, he nevertheless before his departure took care to send me his coat of arms finely painted for which I made him my acknowledgments by a letter into England and sent also his excellency my remarks about pearls, viz. that they were of no use in physic, wherewth his excellency was much satisfyed & thanked me by way of answer.
