Letter, from Antoni van Leeuwenhoek to Henry Oldenburg, dated at Delft Signed autograph States that he will send further observations (see EL/L1/7) For summary see 'The correspondence of Henry Oldenburg', ed and trans by A Rupert Hall & Marie Boas Hall, vol 11, p 72 Transcribed and translated in 'Alle de brieven van Antoni van Leeuwenhoek', edited, illustrated and annotated by Committee of Dutch Scientists, part 1, p 132 7 September 1674