John Chamberlayne
John Chamberlayne learned Dutch while he was studying at Leiden University, beginning in May 1688. Back in England, he was a courtier. In 1702, he was elected a fellow of the Royal Society and later had three articles in Philosophical Transactions. He gained fame as a translator of Gerard Brandt's History of the Reformation in the Low Countries, 4 vols.
Between 1700 and 1722, but mostly from 1700 to 1712, Chamberlayne translated around sixty of Leeuwenhoek's later letters into English for publication in Philosophical Transactions. He wrote about the difficulties of translating Leeuwenhoek's Dutch in letters to Hans Sloane. See What happened below for examples.
Similar letters:
July 30, 1700 O.S. 10 August 1700 N.S.
British Library, Sloane MS 4038, f. 40
20 January 1702/03 O.S. 31 January 1703 N.S.
British Library, Sloane MS 4039, 73-74