ACTUARIUS, Johannes Zacharias.

The complete works of Johannes Zacharias (late C13?), an ‘Actuarius’ (official) at the Byzantine court, and the Emperor’s personal physician. ‘De Actionibus’ discusses the functions and disturbances of the soul-spirit, touching on numerous mental illnesses and their causes, for instance, ‘dietary errors, bodily causes, fatigue, and intemperance. ‘He considered the origin of the soul to be in the pneuma which was formed in the liver and united with the vital spirit in the heart for distribution throughout the body. He recognized five mental functions that distinguish man from animals: reason, understanding, judgment, perception, and imagination’ (Heirs of Hippocrates). First published in 1529 and translated by Ambrogio Leone, ‘De urinis’ is entirely devoted to urinoscopy. It includes a woodcut illustration of the graduated glass which Actuarius was the first to employ for diagnostic purposes. It discusses the origin of urine, its various types and colours, their nature and causes, how to interpret its aspect, texture or residue using the graduated glass, how to study it according to age, sex, lifestyle, etc., and how to infer illnesses from its characteristics. His ‘Methodus Medendi’ is a treatise on medical practice. ‘He believed in treating each case on its individual merits and spoke out against the polypharmacy of his day. Although an adherent of Galen, he did not always agree with him and he was successful in making Galen’s teachings on the pulse clearer and easier to follow. He felt that venesection was of great therapeutic value and provided specific guidance for the best areas to let blood for various disease states. He was perhaps the first to detect and describe the pin worm and also wrote on colic and lead poisoning’ (Heirs of Hippocrates). The final detailed index brings together all the ailments and remedies mentioned in the various works.

USTC records 4 eds printed in 1556 – priority not established.