Letter, from Antoni van Leeuwenhoek to John Chamberlayne, dated at Delft Signed autograph Stating that several letters had been sent to the Royal Society but no answer had been received; observations of bezoar stone (found in the stomach and intestines of animals, usually ruminants) Read to the Royal Society on 7 May 1707 Original letter no longer exists Transcribed in 'Alle de brieven van Antoni van Leeuwenhoek', edited, illustrated and annotated by Committee of Dutch Scientists, vol 15, p 337 17 May 1707