Letter, from Antoni van Leeuwenhoek to the Royal Society, dated at Delft Signed autograph Continuation of the experiments with the air-pump; structure of an insect's wing; blood and 'blood vessels' in an insect's wing; observations of a grey owlet moth; observations of the wing of a very small fly 4 original figures no longer exist; engraved figures for publication are attached English translation is EL/L2/38 Transcribed and translated in 'Alle de brieven van Antoni van Leeuwenhoek', edited, illustrated and annotated by Committee of Dutch Scientists, vol 9, p 37 24 July 1682