WEPFER, JOHANN-JAKOB

(b. Schaffhausen, Switzerland, 23 December 1620; d. Schaffhausen, 26 January 1695), medicine, physiology, toxicology.

Wepfer graduated from the secondary school in Schaffhausen. Among his teachers was Johannes Fabritius of the Palatinate, who taught him natural history and instilled in him a passion for observing the living world. In 1637 Wepfer left Schaffhausen for Strasbourg and then went to Padua, where he studied at the Faculty of Medicine and Pharmacy. In 1647 he received the doctorate in medicine at Basel and became municipal physician of Schaffhausen, where he remained as physician and scientist. Although Wepfer never occupied a faculty chair—Schaffhausen had no university–he had numerous students, J. C. Payer and J. C. Brunner among them, from throughout Europe. He also became the private physician of several German princes, as well as a famous consultant.

In 1647 Wepfer presented two dissertations, Disputatio medica inauguralis de3 palpitaitione cordis and Oratio de thermarum potu. In 1648, when he became municipal physician of Schaffhausen, he was given the right to perform autopsies and made extremely complex observations, using a novel method that was not taken up again until the nineteenth century. He first followed the evolution of an illness, carefully noting all its symptoms. He completed his investigations upon cadavers. Wepfer later sought to confirm his hypotheses by performing experiments on animals, which he described in reports published mainly in the Miscellanea cttriosa issued by the Leopoldina.

Wepfer’s major research centered on the brain and, being a skilled experimentalist, he devised new techniques. For instance, he was the first to color cervical vessels through injecting dye. The essentials of his anatomical observations concerning the nervous system are presented in Historia anatomica de puella sine cerebro nata (1665). In his classic work, reprinted many times, Observationes anatomicae ex cadaveribus eorum, quos sustulit apoplexia, cum exercitatione de eius loco affecto (Schaffhausen, 1658), he collected a large number of original observations based on comparative anatomy of human cadavers. In it he was the first to report that apoplexy involved hemorrhage from blood vessels.

It was in toxicological analysis, however, that Wepfer made his greatest contributions. He systematically studied poisons, with particular attention to the toxic substances synthesized by certain umbellifers, especially the poison and water hemlocks. He was the first to analyze the pharmacological effects of coniine, an alkaloid of hemlock that was not isolated until much later; and his classic description of hemlock poisoning was often cited as the standard. He also experimented upon animals and found an efficacious remedy: the administration of strong emetics. At the same time he noted that coniine, in minute doses, could be useful as an antineuralgic and antispasmodic. He also discovered its remarkable analgesic effect and was the first to use it in minor surgery. One of his publications was Cicutae aquaticae historia et noxae comrncntario illustrata (Basel, 1679). His numerous discoveries about poisons and their uses made Wepfer an undoubted pioneer in toxicology. He also studied the characteristics of mercury poisoning and was the first to indicate the dangers for workers with this metal who fall to take the proper precautions. This study led him to publish articles on occupational diseases.

After Wepfer’s death his heirs, B. and G. M. Wepfer, published some of his writings as Observationes medico-practicae de affectibus capitis internis et externis (Schaffhausen, 1727). As a scholarly physician Wepfer made a tremendous contribution to medical treatment and research through his resolute opposition to the influence of dogmatic and traditionalist scientists who stressed ancient texts rather than actual facts.

BIBLIOGRAPHY

Wepfer’s works are cited in the text.

Secondary literature includes H. Buess, Recherches, decouvertes et inventions de médecins suisses, R. Kaech, trans. (Basel, 1946), 25–26; and H. Fischer, J. Jakob Wepfer (Zurich, 193 1); and Briefe J.J. Wepfer an seinem Sohn Johann Conrad (Leipzig, 1943).

P. E. Pilet