Letter, from Antoni van Leeuwenhoek to Nehemiah Grew, dated at Delft Signed autograph The effect of sun on Leeuwenhoek's skin; observations of saliva; observations of a disease affecting meadows outside Delft Transcribed and translated in 'Alle de brieven van Antoni van Leeuwenhoek', edited, illustrated and annotated by Committee of Dutch Scientists, vol 2, p 381 27 September 1678