Letter, from Antoni van Leeuwenhoek to the Royal Society, dated at Delft Signed letter Observations of the structure of the teeth of elephant, pig, humans, ox, horse; theory about toothache 3 engraved figures Partial English translation see EL/L2/9 Transcribed and translated in 'Alle de brieven van Antoni van Leeuwenhoek', edited, illustrated and annotated by Committee of Dutch Scientists, vol 6, p 191 4 April 1686