[On iatrochemistry, one of its prominent supporters, Otto Tachen, and his principal work].

A survey is given of the transition in the 1600-years from superstition, humoral pathology, astrology, alchemy to spagyric medicine - the Paracelsian revolutionary new medicine: iatrochemistry. A number of persons are mentioned who participated in the proces where the old mingled with the new. The efforts of developping a chemistry necessary for iatrochemistry resulted in a great interest in tectbooks and courses in chemistry as well as spagyric pharmacopoeas. The most important persons in this work are mentioned aming whom a rather unknown-but nevertheless significant physician, Otto Tachen, is particularly described. His work and writings are mentioned and commented-especially his main work: "Antiwuissimae Hippocratiocae medicinae clavis". The provenance of my copy of thes book is related. Tho persons with relation to Denmark are met with: the count Christian Albert of Gottorp and Helwig Bieterich that in a periode the doctor of the crownprince of Denmark (the som of Christian IV).