Lorenz, Richard

(b. Vienna, Austria, 13 April 1863; d. Frankfurt am Main, Germany, 23 June 1929)

physical chemistry.

Lorenz’ father was the historian Ottokar Lorenz; his mother was the daughter of the philosopher and educational reformer Franz Lott. Lorenz studied medicine at the universities of Vienna and Jena, but his main interest was chemistry. He received his doctorate at Jena for work on the valence of boron. After completing his studies he was for a short time an assistant in the physiology institute at the University of Rostock; he left in order to work with Otto Wallach in the chemistry laboratory of the University of Göttingen. Despite this beginning he did not devote his career to organic chemistry, Wallach’s principal field of interest. Instead, he took up the study of physical chemistry. Nernst had just been appointed professor at Göttingen, in the first chair ever dedicated to that subject, and in 1892 Lorenz became an assistant and Privatdozent under him.

Lorenz then began to explore the field in which he worked for the rest of his life—the electrochemistry of substances in the fused state. In 1896 he was invited to the Technische Hochschule in Zurich to join the newly founded electrochemical laboratory. In Zurich he married Lili Heusler, who bore him two children. Following the death of his wife, Lorenz accepted an offer in 1910 from the Frankfurt Academy to direct its physics and chemistry institute. The academy soon became a university, and Lorenz pursued his work there until his retirement, which occurred shortly before his death. For thirty years he was editor of the Zeitschrift für anorganische und allgemeine Chemie.

Lorenz’ most important scientific achievement was his demonstration that Faraday’s law is completely valid for fused salts. He discovered the cause of earlier results which contradicted it in the formation of the so-called metallic fog, which occurs in the reaction of the precipitated metals with the melt. He then found methods which inhibited this fog formation. With M. Katajama he developed the thermodynamic relations to calculate the electromotive force of galvanic cells consisting of fused salts alone or of the latter joined with metals. By determining the particle sizes in disperse systems, which had been suggested by Einstein, he was able to compute the ion sizes in the fused electrolytes from the mobility and the rate of diffusion.

Lorenz’ work contributed to the clarification of many other properties of fused salts, for example internal friction, capillary electricity, and conductivity. In his last years he established that the law of mass action is not valid in highly concentrated fusions. He also developed van der Waals’s equation of state taking this fact into account and, with the aid of the concept of thermodynamic potential, developed of mass action for condensed systems.

BIBLIOGRAPHY

I. Original Works. Lorenz wrote about 250 articles; a fairly extensive listing may be found in Poggendorff VI and in the obituary in the Zeitschrift für Elektrochemie but there is no complete list. His most important books are Die Elektmlyse geschmolzener Salze, 3 vols. (Halle, 1905); Elektrochemie gesehmolzerwr Salze (Leipzig, 1909), written with F. Kaufler; Raumerfüllung und lonenbeweglichkeit (Leipzig, 1922); and Das Gesetz der chemischen Massenwirkung,seine thermodynamische Begründung und Erweite-rung (Leipzig, 1927).

II. Secondary Literature. See W. Fraenkel, “Richard Lorenz,” in Zeitschrift für angewandte Chemie und Zentrablatt für technische Chemie, 42 (1929), 801-802; G. Hevesy, “Richard Lorenz. Erinnerungen aus den Zürcher Jahren,” in Helvetica chimica acta, 13 (1930), 13-17; and A. Magnus, “Richard Lorenz,” in Berichte der Deutschen chemischen Gesellschaft, Abt. A, 62 (1929), 88-90; and “Richard Lorenz,” in Zeitschrift für Elektrochcmie und angewandte physikaiische Chemie, 35 (1929), 815-822.

F. SzabadvÁry