The Royal Society received Leeuwenhoek's first letter

Date: 
May 7, 1673

Mr. OLDENBURG produced a book of Dr. de GRAAF dedicated to the Society, intitled, Regneri de Graaf Partium Genitalium Defensio, together with a letter to Mr. OLDENBURG, dated at Delft in Holland, 28th April, 1673, communicating some microscopical observations of Mons. LEEWENHOECK.

Oldenburg published his translation of this letter in the next edition of Philosophical Transactions, number 94, dated May 19, 1673.

Document: 

Birch's History, vol. III, p 88