Henry Oldenburg wrote to Leeuwenhoek acknowledging reciept of his letters

Date: 
August 22, 1675

August 22 was the date in Holland when Oldenburg wrote this letter in London, where it was August 12.

Leeuwenhoek mentioned this letter at the beginning of his letter of 1675-12-20.

Document: 

Correspondence of Henry Oldenburg, vol. XI, p. 456

Sources