Wiegleb, Johann Christian

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(b. Langensalza, Germany, 21 December 1732; d. Langensalza 16 January 1800)

pharmacy, chemistry.

From the end of the seventeenth century, apothecaries played an increasingly active role in scientific research, especially in chemistry. The expansion of the number of medicines through the addition of chemical preparations, begun by Paraceluss, was at first supported by physicians. Later this development stimulated apothecaries to undertake investigations of their own, however, many of which went far beyond the confines of their professional interests. Wiegleb was one of the most important figures among this steadily growing group.

His father, a lawyer, died while Wiegleb was still young; and his mother remarried–again a lawyer–in order to provide a good upbringing for her children. While still at school Wiegleb was an assistant to his stepfather, and thus acquired considerable skill in the use of language and knowledge of legal matters.

Wiegleb was related to several local apothecaries and, by observing them at work, the became interested in entering the profession. Although his family would have preferred him to become a theologian, they allowed him to make his own decision. In 1748, at age sixteen, Wiegleb began his apprenticeship at the Marienapotheke, in Dresden. Unfortunately, the proprietor took virtually no interest in his training, leaving this matter to his assistants, who were far from equal to the task. As a result Wiegleb learned only manual skills. He therefore had to study on his own; and in order to master the relevant technical writings, most of which were in Latin, Wiegleb had to better his scanty knowledge of the language. This he did with great enthusiasm, practicing on the scholarly books he found in the shop, although many of them were outdated. In the beginning he was especially drawn to alchemical writings, which for a time he considered to be the summit of human knowledge.

Wieglab’s apprenticeship lasted six years; but since no successor could be found for him, he remained in Dresden for another six months. The next year he was an assistant to an apothecary in Quedlinburg but, receiving no more instruction there than in his previous position. he returned to Langensalza. The owner of the apothecary shop there had just died; and Wiegleb, now aged twentysix, was offered the opportunity to manage it for the man’s widow. But, wishing to be fully independent, he declined the offer and with money inherited from his parents, built his won pharmacy. The new building, which was finished in 1759, contained a splendid shop and a model laboratory.

During this period Wiegleb became friendly with Ernst Baldinger, a physician practicing in Langensalza who was very interested in scientific research and who later held professorships at Jena and Marburg. The two men conducted chemistry experiments together, and in the course of their work Baldinger acquainted Wiegleb with the latest developments in chemistry. In 1767 Wiegleb published his first book, which contained a number of brief writings. This was followed by a work on fermentation. He then investigated the alkaline salts found in plants and confirmed Marggraf’s discovery of this type of substance. In a number of papers Wiegleb displayed an excellent knowledge of analytic procedures. For instance, he repeated with remarkable exactness the analyses of Torbern Bergman and corrected a considerable number of the latter’s errors.

In 1775 Wiegleb published a German translation of R. A. Vogel’s Institutiones chemiae, a work he greatly admired. It probably was while preparing the book for publication that Wiegleb decided to create an institute for training pharmacists, and he founded such a school in 1779. There the students, after attending lectures, were expected to participate in laboratory experiments and to do independent work. They had the use of an extensive library and could obtain instruction in languages. Later critics believed that the teaching was more suited to training chemists than to providing a general knowledge of all branches of pharmacy, but this view seems exaggerated. In the approximately twenty years of his existence, the school trained about fifty students, including J. F. A. Göttling (later a professor of chemistry at Jena), Klaproth, Hermbstädt, and the botanist Wildenow–which suggests that the curriculum was, in fact, broadly based.

Wiegleb’s reputation extended far beyond northern Germany: scientists from throughout Europe visited him. Besides purely scientific questions, he was much concerned with improving technology. Whenever he could, he supported such crafts as dyeing and brewing. Wiegleb even studied the economic problems of Langensalza, and he was elected both a member of the city council and municipal treasurer.

Very little is known about Wiegleb’s family. He had nine children, four of whom survived him. Two of the children were deaf and dumb. The last years of his life were difficult, for in 1789 an accident with fulminate of mercury almost blinded him. In addition, he sold his apothecary shop but lost most of the purchase price.

Wiegleb’s critical attitude in assessing scientific questions earned him high esteem in learned circles. After several years of work he published Historisch-kritische Untersuchung der Alchemie (1777), which went through a second edition. In this work he stated:

The best accounts from the period when the name alchemy is encountered, . . . are examined, and it is thereby demonstrated that they are, taken together, incapable of confirming the reality of alchemy. Then, the strongest proof is adduced to show that the entire imaginary art of alchemy is impossible according to all known, certain natural laws of human art: thus [it is shown] that it has never truly been practiced by anyone.

Wiegleb carefully examined famous reports of the transformation of metals and pointed out their deficiencies: in a short time his work became widely known. His motto was “To doubt is the beginning of knowledge,” so it is all the more as tonishing that Wiegleb was a convinced proponent of Stal’s phlogiston theory throughout his life. He believed that phlogiston was a “subtle but destructible” substance that never can be produced in the pure state. Somewhat later the conjectured that phlogiston is a kind of hydrogen. Even after the triumph Lavoisier’s ideas, Wiegleb did not abandon the phlogiston theory. For a long time he contended that phlogiston possessed a negative weight. In the ensuing debates he argued objectively with his opponents and even adopted several of their experimental findings–for instance, he considered the two hypothetical “substances” light and phlogiston to be identical. On the whole. however, he clung to Stahl’s theory.

After his book on alchemy, Wiegleb published a great many works. In 1779 he reported that oxalic acid is a separate compound. He also devised an improved method of preparing Glauber’s salt and took special pains to work out new and improved mineral analyses. Wiegleb was interested in the history of chemistry and wrote a two-volume work on the subject, as well as a history of gunpowder.

Except for an educational trip to almost all the countries of Europe, Wiegleb never left his native city. Nevertheless, at his death he was one of Germany’s best-known men of learning.


I. Original Works. Wiegleb’s writings include Kleine chymische Abhandlungen von dem grossen Nutzen der Erkenntniss des acidi pinguis bey der Erklärung vieler chymische Erscheinungen (Langensalza, 1770), which contains “Entstehung des Glases.” “Grüne Flamme borhalt. Alkohols,” and “Über die rote Farbe des Zinnobers” ; Vertheidigugng der Mayerischen Lehre vom acido pingui gegen verschiden dawider gemachte Einwedungen (Altenburg, 1770); Chymische Versuche über die alkalischen Salze (Berlin, 1774); Fortgesetze kleine chymische Abhandlungen (Langensalza, 1770), which contains “Farbe des Quecksilberoxydes” and “Zerlegung des Salmiaks durch Eisen” ; Rudolf Aug. Vogels Institutions chemiae als Lehrsätze der Chemie (Weimar. 1775: 2nd ed., 1785); Neuer Begriff von der Gährung und den ihr unterwürfigen körpern (Weimar, 1776); Geschichte der Alchemie: Historisch-kritische Untersuchung der Alchemie oder der eingebildeten Goldmacherkunts, von ihrem Ursprunge als Fortgang . . . (Weimar, 1777; 2nd ed., 1793); Revision der Grundlehren von der chemischen Verwandtschaft der Körper (Erfurt, 1777); “Untersuchungen der Waffen der Bronzezeit,” in Acta Acadmiae Electonum Moguntiace scientiarum utilis (Erfurt, 1777), and Die natürliche Magie (Berlin, 1779; 1782–1786), completed by G.E. Rosenthal (1805).

Further works are “Über Oxalsäure,” in Chemisches Journal, 2 (1779); Handbuch der Allgemeine Cheinie (Berlin, 1781: 2nd ed., 1787: 3rd ed., 1796), also translated into English by C. R. Hopson as General System of Chemistry Theoretical and practical, Digested and Arranged With a Particular View to Its Application . . . (London. 1789); P. v. Muschenbroeks Elementa Chemiae als Anfangsgründe der Chemie (Berlin, 1782); Onomatologia curiosa artificiosa et magica order natürliches Zauberlexikon (Nuremberg, 1784): Unterhaltende Naturwunder (Erfurt. 1788), written with F. Kroll: “Über Phlogiston,” in Chemische Annalen, 2 (1791): Geschichte des Wachstums und der Erfindungen in der Chemie in der ältesten und mittleren Zeit, aus dem Lateinischen werk Bergmans mit Zusätzen (Berlin, 1792); Deutsches Apothekerbuch, 2 vols. (Gotha, 1793; 4th ed., 1804), written with J. C. T. Schlegel; “Herstellung der Soda aus Kochsalz mit Hilfe von Vitriol,” in Chemische Annalen (1793); “Chemische Nomenclatur,” ibdi., 2 (1796): and “Verkalken des Bleies,” ibdi.,1 (1797).

Wiegleb also published many essays in booklet from for ananlytic chemists. In additiona, he translated works by Boerhaave and Demachy, and edited writings by G. A. Hoffmann, Dorothea Erxleben, and others.

II. Secondary Literature. See H. Gutbier, Beiträge zur Geschichte dert Apotheken in Langensalza (Lagensalza, 1929); and R. Möller, “Ein Apotheker und Chemiker der Aufklärung,” in Pharmazie (Berlin), 20 (1965), 230–239.

Gunther Kerstein