MAGNUS, HEINRICH GUSTAV

(b. Berlin, Germany, 2 May 1802; d. Berlin, 4 April 1870)

physics, chemistry.

Magnus’ father, Johann Matthias Magnus, the prosperous founder of a large trading firm, was able to provide his son with private instruction in mathematics and natural science. Magnus entered the University of Berlin in 1822; and in 1825 he published his first paper, an investigation of pyrophoric iron, cobalt, and nickel carried out under the direction of Eilhard Mitscherlich, discoverer of the law of isomorphism. After receiving his doctorate in September 1827 with a dissertation on tellurium, Magnus took the advice of Mitscherlich, Heinrich and Gustav Rose, and Friedrich Wöhler, all former students of Berzelius, and in October 1827 went to Stockholm to study with the great Swedish chemist, who became his lifelong friend and adviser.

It was in Berzelius’ laboratory that Magnus not only discovered the first platinum-ammine compound (Magnus’ green salt [Pt(NH₃)₄][PtCl₄]) and its related potassium salt (K₂[PtCl₄]) but also worked on the addition compound of ethylene and platinous chloride later described by the Danish chemist W. C. Zeise (Zeise’s salt, K[Pt(C₂H₄)Cl₃]). In the summer of 1828 Magnus returned to Berlin, where, with the exception of a visit to Paris during 1828 and 1829, he remained until his death. His Habilitations-schrift on mineral analysis (1831) permitted him to begin lecturing on technology at the university and on chemistry at the municipal trade school but led to a break with his teacher Mitscherlich, who regarded the young Privatdozent as a dangerous competitor. In 1833 Magnus was appointed associate professor and in 1845 professor of technology and physics at the University of Berlin, where he also served as rector during 1861 and 1862. He married Bertha Humblot in 1840. Magnus became a member of the Berlin Academy of Sciences in 1840 and was one of the founding members of the German Chemical Society (1868). A number of his students became famous physicists.

As was true of most chemists of the time, Magnus’ research interests were varied. From an initial interest in mineral analysis, he turned to inorganic chemistry, discovering periodic acid and its salts in 1833; organic chemistry, discovering ethionic and isethionic acids in 1833–1839 and the polymerization of hydrocarbons on heating in 1853; physiological chemistry, studying the oxygen and carbon dioxide content of blood in 1837– and agricultural chemistry in 1849. Magnus gradually turned to physicochemical and eventually purely physical investigations, which constitute his most important scientific achievements. Among these are his contributions to the theory of heat, thermal expansion of gases, boiling of liquids, vapor formation, electrolysis (Magnus’ rule), induced and thermoelectric currents, optics, hydrodynamics, magnetism, and mechanics. Although his most important work was in physics, he never ceased investigating chemical problems in his private laboratory. These later chemical works, however, never led to results of general significance but served merely for his own instruction.

Neither a theoretician nor an original thinker, Magnus was, however, an acute, conscientious, and diligent experimenter who uncovered much valuable physical and chemical information—notably the Magnus effect.

BIBLIOGRAPHY

I. Original Works. Magnus’ papers are listed in the Royal Society Catalogue of Scientific Papers, IV, 182–184; VIII, 306. See esp. “Ueber die Eigenschaft metallischer Pulver, sich bei der gewöhnlichen Temperatur von selbst in der atmosphärischen Luft zu entzüunden,” in Annalen der Physik und Chemie, 3 (1825), 81–88; “Ueber einige neue Verbindungen des Platinchlorürs,” ibid., 14 (1828), 239–242, with English trans. in G. B. Kauffman, ed., Classics in Coordination Chemistry, Part II. Selected Papers (1798–1935) (New York, in press); and “Ueber die Weinschwefelsäure, ihren Einfluss auf die Aetherbildung, und über zwei neue Säuren ähnlicher Zusammensetzung,” ibid., 27 (1833), 367–387.

II. Secondary Literature. See the notices by A. W. Hofmann, in Berichte der Deutschen Chemischen Gesellschaft, 3 (1870), 993; and A. W. Williamson, in Journal of the Chemical Society, 24 (1871), 610–615.

See also J. J. Berzelius, Aus Jac. Berzelius und Gustav Magnus’ Briefwechsel in den Jahren 1828–1847, E. Hjelt, ed. (Brunswick, 1900); and W. Prandtl, Deutsche Chemiker in der ersten Hälfte des neunzehnten Jahrhunderts (Weinheim, 1956), 303–314).

George B. Kauffman

MAGNUS, HEINRICH GUSTAV

MAGNUS, HEINRICH GUSTAV (1802–1870), German chemist and physicist. Magnus, who was born in Berlin into a wealthy family, left Judaism. He began teaching at the University of Berlin in 1831. From 1845 to 1869 he was professor of physics and technology at Berlin, and in 1861 became rector of the university. His numerous discoveries include the first platinum-ammonia complex, Magnus' green salt (Pt(NH₃)₄)Pt-CI₄) and the "Magnus Effect." The latter referred originally to projectiles which, subjected to rapid rotation, are turned aside from their original direction by forces which act upon them crosswise. It has important aerodynamic applications.

bibliography:

Huntress, in: Proceedings of the American Academy of Arts and Science, 81 (1952), 70f.

[Samuel Aaron Miller]