(b. Züllichau, Germany [now Sulechόw, Poland], 11 July 1683; d. Berlin, Germany, 20 October 1737)
The first child of a merchant-musician, Caspar Neumann was intended for the clergy. He learned music from his father and studied at the local Latin school. But, orphaned at the age of twelve, he had to go into pharmacy as an apprentice to his godfather. He showed such aptitude that three years later his guardian put him in charge of an apothecary shop. brewery, and distillery in nearby Unruhstadt. Neumann remained there until 1704, when the Great Northern War forced him to flee to Berlin. In the Prussian capital he soon became an assistant to the traveling pharmacist of Frederick I. As part of the royal entourage, he played the clavier for the king, he traveled throughout Germany and Holland, and he pursued a growing interest in science and medicine.
Neumann’s serious scientific education began in 1711, when, apparently at the urging of the renowned royal physician F. Hoffmann, he was sent abroad to study chemistry. He first visited the Harz mining towns, where he learned assaying and smelting, and then went to Holland, where he inspected large chemical works and studied with Boerhaave. In 1713 he went to London, where he was stranded because of the recent death of his royal patron. He found employment as a laboratory assistant to the wealthy Dutch surgeon A. Cyprian, who spent £1,000 annually on chemical experiments. In his free time, Neumann gave private courses on chemistry and participated in the scientific life of London. After three years there he returned to Berlin to collect his belongings. Stahl, who had recently been made royal physician, persuaded Neumann to reenter Prussian service by obtaining a continuation of his travel stipend and promising him a position in the court apothecary shop. On his second tour Neumann first visited his friends in London. Then he proceeded to Paris, where he attended courses on chemistry and botany; taught a course of his own on chemistry; experimented two afternoons weekly with C. J. and E. F. Geoffroy; and made the acquaintance of all the leading scientists. In 1719 he returned to Berlin by way of Rome.
Upon his return, Neumann as court apothecary took on the demanding job of running one of Europe’s busiest pharmacies. Nevertheless, he managed to find time for other activities. In 1721 he began active membership in Berlin’s Society of Sciences, and in 1724 he became a member of the chief Prussian medical board and began teaching in the new Medical-Surgical College as professor of practical (experimental) chemistry. He remained in all these positions until his death in 1737 at the age of fifty-four.
In the mid-1720’s, after more than a decade of serious work in chemistry, Neumann began his short yet prolific career as an author with a series of articles in the Philosophical Transactions. After his death his collected lectures appeared in two German versions and, partially at least, in English, Dutch, and French translations.
Though Neumann was not a highly original chemist, he did influence the development of chemistry in a variety of ways. First, during his Wanderjahre, he conveyed knowledge of German techniques and theories to chemists in London and Paris. Second, as master pharmacist and as professor, he gave the young Marggraf his initial instruction in chemistry. It may well have been Neumann’s exhortations that inspired Marggraf to develop “wet” analysis. Third, as an author he contributed significantly to the establishment of Stahlian chemistry, especially in Germany but also abroad. Like Stahl’s other main disciples—Pott. Henckel, and Juncker—Neumann distinguished clearly between pure and applied chemistry and insisted that the chemical approach to nature was vastly superior to the mechanical philosophy. He envisioned many levels of chemical aggregation and invoked the phlogiston theory to explain combustion and calcinationreduction. Unlike Stahl’s other main disciples, Neumann concentrated on pharmaceutical chemistry, thereby reaching and inspiring a generation of pharmacists which included Scheele and Klaproth.
I. Original Works. See Praelectiones chemicae seu chemia medico-phamaceutica experimentalis & rationalise oder grünndlicher Unterricht der Chemie … (Berlin, 1740), edited on the basis of student notes by J. C. Zimmermann with the assistance of J. H. Pott, with portrait. Zimmermann republished this ed. with minor changes under his own name in 1755. Neumann’s nephew C. H. Kessel put out a different ed. which was based on Neumann’s own notes, Chymiae medicae dogmatico-experimentalis… oder der gründlichen and mit Experimenten erwiesenen Medicinischen Chymie …, 4 vols. (Züllichau, 1749–1755; partial reprint, 1755–1756). W. Lewis’ English ed. appeared in 1759 and 1773, the Dutch ed. in 1766, and Roux’s French ed. in 1781. A complete bibliography of Neumann’s works which mentions many reviews appears in Exner’s biography, cited below, and an annotated partial bibliography in J. R. Partington, A History of Chemistry, II(London-New York, 1961), 702–706.
II. Secondary Literature. The best biography is Alfred Exner, Der Hofapotheker Caspar Neumann (1683–1737) (Berlin, 1938). Exner begins with an annotated trans, of A. P. Queitsch’s Latin biography (1737) and then, relying heavily on Kessel’s ed. of the lectures, he assesses Neumann’s role in chemistry and pharmacy. Some additional materials are in Herbert Lehmann, Das Collegium medico-chirurgicum in Berlin als Lehrstātte der Botanik und der Pharmazie (Berlin, 1936).