Letter, from Antoni van Leeuwenhoek to Henry Oldenburg, dated at Delft Signed autograph Discovery of five different 'animalcules' (micro-organisms - one possibly bacteria) in pepper-infused water and carries out experiments with rain-, well-, moat-, sea-, and river-water, and infusions of various spices; an account of the structure of a peppercorn, wheat, ginger; whether or not there are organisms in the air Four figures in the margin (particles of pepper grain and in ginger-water) Partial translation by Oldenburg see EL/L1/23 Transcribed and translated in 'Alle de brieven van Antoni van Leeuwenhoek', edited, illustrated and annotated by Committee of Dutch Scientists, vol 2, p 61 For summary see 'The correspondence of Henry Oldenburg', ed and trans by A Rupert Hall & Marie Boas Hall, vol 13, p 82 Partial translation printed in 'Philosophical Transactions', vol 12, no 133, p 821 B&W negative, first page only, Box N101. IM/005317 9 October 1676