Letter, from Antoni van Leeuwenhoek to Richard Waller, dated at Delft Signed autograph Sent a number of copies of his portrait to the Royal Society; concerning different opinions about the circulation of blood in animals Transcribed and translated in 'Alle de brieven van Antoni van Leeuwenhoek', edited, illustrated and annotated by Committee of Dutch Scientists, vol 10, p 145 14 September 1694