Translation of a letter, from Antoni van Leeuwenhoek to John Chamberlayne Original letter no longer exists Concerning dental hygiene: Leeuwenhoek recommends polishing with salt and ash of tobacco, and that tea and coffee are not harmful to teeth Read to the Royal Society on 23 December Printed in 'Alle de brieven van Antoni van Leeuwenhoek', edited, illustrated and annotated by Committee of Dutch Scientists, vol 14, p 151 8 December 1702