Preface
It is a source of satisfaction for the Commission that it has succeeded in publishing Volume X of the Collected Letters of Antoni van Leeuwenhoek within a reasonable time from the appearance of the preceding volume.
Partly with a view to preventing undesirable delay in publication the Editor has altered his policy to the extent that the explanatory notes by external collaborators have been somewhat restricted, while he will no longer wait indefinitely for notes which, though promised, have not been received.
Volume X contains Letters 134 to 147 incl., written between 2 March 1694 and 10 July 1695; it thus covers a period of about sixteen months. Eleven of these letters were numbered by Van Leeuwenhoek himself: 80 to 90 incl. They are addressed to the Royal Society and to Richard Waller, Pieter Rabus, Antoni Heinsius, and Frederik Adriaan van Reede van Renswoude.
The other three letters are so-called intermediate letters, addressed to R. Waller (138), P. Rabus (145), and Maarten Etienne van Velden (146).
Further, three letters addressed to Van Leeuwenhoek have been included. They were written by B(enedictus) H(aan), George Garden (both incorporated in Letter 135), and Richard Waller (after Letter 136).
In Letter 134 Van Leeuwenhoek reports not only on his research about ear wax and the small hairs in the external auditory canal; he also describes interesting experiments carried out on himself to measure the amount of sweat which the body loses along the skin. Here the experimenter is speaking.
In Letter 135 he reproduces a translation of a letter from George Garden, who wants to convince him that the ovaries are necessary for reproduction. Being an animalculist, Van Leeuwenhoek is not to be convinced and advances counter-arguments.
The circulation of the blood continues to fascinate him. In Letters 139 and 141 he describes his observations about it in the leg of a crab, in Letter 145 he reports on his findings in a ray. In Letter 147 Van Leeuwenhoek writes for the first time about his research on aphids.
The publication of some of these letters was still prepared by Mr J. Heniger, to whom the Commission is indebted for the publication of the preceding volume. On 1 January 1976 he was succeeded as editor by Mr L.C. Palm, a member of the staff of the Institute for the History of Science, Utrecht; after the retirement of Prof. Dr R. Hooykaas this Institute is now directed by Prof. Dr H.A.M. Snelders.
In connection with the desired speeding-up of the appearance of the present volume the notes included are indeed less detailed, but their number has certainly not been reduced proportionately. The scientific notes of the collaborators were signed as indicated in the List of Collaborators; the unsigned notes were written by the present editor. The separation between variants of the text and scientific notes has been maintained.
Dr B.C. Damsteegt, lecturer in Dutch philology at Leiden University,