Letter, from Antoni van Leeuwenhoek to Henry Oldenburg, dated at Delft Signed autograph An account of the bile of cow, sheep, rabbits and poultry; microscopic observations of the structure of metals; structure of skin; structure of the bladder; theories for the sense of taste For summary see 'The correspondence of Henry Oldenburg', ed and trans by A Rupert Hall & Marie Boas Hall, vol 11, p 104 Transcribed and translated in 'Alle de brieven van Antoni van Leeuwenhoek', edited, illustrated and annotated by Committee of Dutch Scientists, part 1, p 168 19 October 1674