Barchusen, Johann Conrad

(b. Horn, Germany, 16 March 1666; d. Utrecht, Netherlands, 2 October 1723)

chemistry, medicine.

Little is known of Barchusen’s life before he settled in Utrecht, but it appears that he studied pharmacy in several cities, including Berlin, Mainz, and Vienna. He also traveled in Hungary and Italy and, for a short period in the latter half of 1693, acted as physician to Francesco Morosini during the abortive Venetian expedition to the Peloponnesus. Sometime in 1694 Barchusen settled in Utrecht, where in September of that year he was granted permission by the city council to conduct chemistry courses for students attending the university. In April 1695, at the behest of the city fathers and with their financial support, he was provided with a laboratory. In these circumstances Barchusen taught chemistry as a Privatdozent until 1698, when, again on the initiative of the city council, he was awarded an honorary M.D., granted an annual salary, and given the title of “lector” in chemistry, which allowed him to teach publicly in the university. He was promoted to extraordinary professor of chemistry in 1703. In 1699 Barchusen married a native of Utrecht, Maria Johanna Pylsweert, who died without issue in 1717.

Barchusen’s published work reflects his personal development from practicing pharmacist to professor of a new academic discipline, chemistry. His first book was a pharmaceutical text, Pharmacopoeus synopticus (1690). His chemical writings are contained in three works, published after his arrival in Utrecht: the Pyrosophia (1698), which was later revised and republished with the title Elementa chemiae (1718); the Acroamata (1703), a collection of his public lectures on chemistry; and the Compendium ratiocinii chemici (1712), a brief work that attempts to set out the principles of chemistry in the form of a geometry textbook, with definitions, postulates, theorems, and so on.

The Pyrosophia is a formal, systematic textbook that deals with the principles of chemistry, both theoretical and practical, and then attempts to demonstrate their applications to natural philosophy, medicine, metallurgy, and alchemy. The bulk of the work is descriptive, preparative iatrochemistry of a conventional type; but the syllabi of his laboratory courses for 1695 to 1697, included as an appendix to the volume, show an increasing tendency to emphasize chemistry as the analysis and synthesis of bodies by fire, relegating the preparative iatrochemistry to a secondary part of the course. All the syllabi contain sections devoted to metallurgical assay and to alchemy. In this last part, the students were shown how most alleged transmutations could be explained in terms of displacement reactions of metals. The Elementa chemiae contains a remarkable set of symbolic alchemical plates. The most interesting lectures in the Acroamata are his inaugural of 1703, on the antiquity and utility of chemistry; a lecture defending the technique of analysis by fire and the concept of chemical principles or elements, directed against Robert Boyle; and two lectures attacking John Mayow’s ideas on nitro-aerial spirits. Throughout his chemical writings Barchusen seeks to combine an interpretation of chemical reactions in terms of principles or elements with a corpuscular view of matter. The most thoroughly mechanistic of his works is the short Compendium. Here (p. 12) he postulates that corpuscles of chemical substances differ not only in shape but also in weight. Although he cites Becher and Stahl several times, Barchusen makes no mention of phlogiston.

As a chemist, Barchusen contributed little to the practical or conceptual development of his subject; he has been credited with some originality in his ideas on chemical affinity, but these appear to be derived from Mayow, Homberg, and others. His activities at Utrecht, however, illuminate the Dutch academic chemistry from which his illustrious contemporary at Leiden, Hermann Boerhaave, emerged as the most influential teacher of chemistry in the first decades of the eighteenth century.

Barchusen’s Historia medicinae (1710) is arranged in dialogue form, with several contemporary Dutch physicians discussing certain historical themes and systems in medicine. It was revised and republished with the title De medicinae origine et progressu dissertationes (1723) because of criticism of the dialogue form and the poor Latin style (a characteristic of all his writings). The Collecta medicinae practicae generalis (1715) arose out of Barchusen’s dissatisfaction with the confusion of medical systems that he encountered in writing his history of medicine: here he collected some of the more important clinical observations in the work of ancient and modern physicians to support his view that true progress in medicine would be achieved through extensive clinical observation and empirical therapy.

BIBLIOGRAPHY

I. Original Works. Since considerable confusion exists in the standard bibliographies, a full list of Barchusen’s works follows. His chemical works are Pharmacopoeus synopticus, seu synopsis pharmaceutica, plerasque medicaminum, compositiones, ac formulas, eorumque... conficiendi methodum exhibens (Frankfurt, 1690; 2nd ed., Utrecht, 1696), 3rd ed. entitled Synopsis pharmaciae (Leiden, 1712): Pvrosophia, succincte atque breviter iatrochemiam, rem metallicam et chrysopoeiam pervestigans. Opus medicis, phvsicis, chemicis, pharmacopoeis, metallicis ec. noninutile (Leiden, 1698), 2nd ed., rev., entitled Elementa chemiae, quibus subjuncta est confectura lapidis philosophici imaginibus repraesentata (Leiden, 1718); Acroamata, in quibus complura ad iatro-chemiam atque physicam spectantia. jocunda rerum varietate, explicantur (Utrecht, 1703); and Compendium ratiocinii chemici more geometrarum concinnatum (Leiden, 1712). The medical works are Historia medicinae (Amsterdam, 1710), 2nd ed., rev., entitled De medicinae origine et progressu dissertationes (Utrecht, 1723); and Collecta medicinae practicae generalis (Amsterdam, 1715).

II. Secondary Literature. The fullest account of Barchusen’s early life is in Caspar Burmann, Traiectum eruditum (Utrecht, 1750), p. 14. His career at Utrecht is discussed in O. Hannaway, “Johann Conrad Barchusen (1666–1723)—Contemporary and Rival of Boerhaave,” in Ambix, 14 (1967), 96–111, where an extensive list of secondary literature is cited.

Owen Hannaway