Herman Boerhaave, A new method of chemistry (London, 1727), p. 39.
Worth had both a copy of Johann Conrad Barchusen’s Pyrosophia (Leiden, 1698) and also the revised and enlarged edition of the same work published under the title Elementa chemicae at Leiden in 1718. Barchusen (1666-1723) had studied with pharmacists in Berlin, Mainz and Vienna before settling at the University of Utrecht where he inaugurated chemical teaching in 1694. At that time he was as yet a private teacher of chemistry, although his course had received approval from the Utrecht town council. Hannaway (1967) suggests that the town council’s support for Barchusen’s courses owed much to a desire to keep his teaching there (they had already lost Carel de Maets to the more prestigious University of Leiden). In 1698 they again showed their support, awarding him a salary of 250 guilders and petitioning the University to grant him the degree of Doctor of Medicine so that he would officially be part of the teaching staff of the university. As Hannaway argues, this not only demonstrates the extent of the power the town council had but was also ‘a singular acknowlgement of a new academic status for the chemist’. By 1703 Barchusen had become Professor of Chemistry at Utrecht, a position he held until his death in 1723. It was the only position he held, for unlike other chemical appointees elsewhere who invariably held their positions as chemical lectures in conjunction with other posts within their universities, Barchusen was employed as a chemist alone.
Johann Conrad Barckhausen, Pyrosophia… (Leiden, 1698), p. 67.
Barchusen’s Pyrosophia (literally ‘Knowledge of Fire’), published in 1698 on the occasion of his attaining formal status within the university, contains his 1695 course in an appendix. In his synopsis of his 1695 course Barchusen declared the aim of chemistry as being to demonstrate how ‘sublunary bodies can be reduced into four different substances or principles: namely salt, oil, water, and earth; and [how] these [can be] examined within various mixtures and combinations by the work of different fires and procedures’. As Moran states (2005), the Pyrosophia outlined three different types of chemistry: iatro-chemistry (medical chemistry); metallurgic chemistry; and, finally, ‘alchemistica’ (hermetic chemistry).
Barchusen’s Pyrosophia was, as Hannaway (1967) argues, conceived of as a comprehensive survey on chemistry, one which owed much to earlier formulations such as Rolfinck’s edition of Brendel’s Chimia in Artis Formam Redacta (Jena, 1661) and the French chemical textbooks by Nicaise Le Févre and Nicolas Lémery (all works which were collected by Worth). Alongside his four elements of salt, oil, water and earth he added ‘proximate’ principles of metals: (including mercury, antimony and sulphur). He explained their operations in a mechanistic sense and provided a host of experiments to demonstrate his conclusions. Hannaway gives us an outline for some cited during the second semester of his 1697 course, experiments specifically concerning sodium chloride (salt). Barchusen paid particular attention to the laying out of laboratories and included not only an illustration of his own laboratory (visible on the Home Page of this website), but also of the various instruments within it.
The inclusion of a number of plates of alchemical symbolism (such as the the illustration at the top of this webpage) in the expanded third section in the second edition make it a difficult work to decode. Barchusen didn’t include ‘transmutation of metals’ as part of his course but he did explore a number of related topics in the ‘metallurgy’ section of his course: the separation of gold from silver using aqua fortis and the purification of gold using either mercury or antimony. Though he did not discount the theoretical possibility of transmutation of gold he was ultimately concerned with the rational chemical explanation of so-called transmutations.
Boerhaave, Herman (1727), A new method of chemistry (London).
Hannaway, Owen (1967), ‘Johann Conrad Barchusen (1666-1723) – contemporary and rival of Boerhaave’, Ambix 14, 96-111.
Moran, Bruce T. (2005), Distilling Knowledge. Alchemy, Chemistry, and the Scientific Revolution (Harvard).by