This volume (the 14th of a series of 19) contains 21 letters written between August 1701 and March 1704. At least half of these letters were addressed to Fellows of the Royal Society in London. Every volume in the series contains the texts in the original Dutch and an English translation. The great range of subjects studied by Van Leeuwenhoek is reflected in these letters: instruments to measure water; pulmonary diseases; experiments relating to the solution of gold and silver; salt crystals and grains of sand; botanical work, such as duckweed and germination of orange pips; descriptions on protozoa; blood; spermatozoa; and health and hygiene, for example and harmfulness of tea and coffee and the benefits of cleaning teeth.;Volumes One to 13 are available at a reduced price from Swets and Zeitlinger.