Grotthuss, Theodor (Christian Johann Dietrich) von

(b. Leipzig, Germany, 20 January 1785; d. Geddutz, near Jelgava, Courland, Russia [now Lithuanian S.S.R.], 26 March 1822)

chemistry, physics.

Grotthuss came from an old and distinguished family of Courland chancellery nobility. He was born while his parents were abroad. His father, an amateur composer and collector of natural science material, died while still young. Grotthuss lived on his mother’s estate, Geddutz, and received a good education there. From 1803 to 1808 he completed his education in science in Leipzig, Paris, Naples, and Rome, and was an auditor at the École Polytechnique in Paris, studying with Antoine de Fourcroy, Claude Berthollet, Louis Vauquelin, and Domenico Morrichini, among others. In 1805, while in Italy, he presented an original explanation of the electrolysis of water, which postulated that molecules of water and salt are polarized and, under the influence of the electric poles, form in the solution electromolecular chains whose members at each end are discharged at the opposite poles of the current. The mechanism of electroconductivity according to Grotthuss was generally accepted until the appearance of the electrolytic dissociation theory and is now used to explain the anomalous high electroconductivity of hydrogen and hydroxyl ions.

After his return from France, Grotthuss spent the last part of his life on his mother’s estate, not far from Jelgava, the capital of Courland, where in seclusion he conducted scientific experiments and constructed new theories; only in 1812, to save himself from Napoleon’s invasion, did he go to St. Petersburg for six months. Grotthuss reported the results of his work to the Courland Society of Literature and Art, of which he was an active member; he had his articles published in the proceedings of this society, as well as in German journals of chemistry and physics (Johann Schweigger’s Journal für Chemie und Physik, L. W. Gilbert’s Annalen der Physik, Adolph Gehlen’s Neues allgemeines Journal der Chemie) and in A. N. von Scherer’s Allgemeine nordische Annalen der Chemie, published in St. Petersburg from 1819 to 1822. His articles and notes amount to more than seventy.

In the period from 1808 to 1822 Grotthuss discovered experimentally the basic laws of photochemistry (that a chemical reaction can be caused only by the light absorbed by a substance and that the chemical effect of light is proportional to the time of exposure [1818]), produced original theories on the nature of phosphorescence and color (1815), and attempted to develop a unified electromolecular conception of various chemical and physical phenomena (which anticipated certain elements of the modern kineticmolecular theory). In studying the flames of gas mixtures Grotthuss came to the conclusion that components of the mixtures (i.e., individual gases such as H₂ and O₂) react among themselves only at a certain concentration (pressure), that a gas mixture in a narrow tube will not ignite, and that a spark or an open flame is necessary for an explosion (1811). Humphry Davy used these results in his construction of the miner’s safety lamp (1815). In later years Grotthuss and Davy carried on a polemic concerning the explanation for the action of this lamp.

Grotthuss worked out detailed methods for obtaining, and studied the properties of, thiocyanic (sulfocyanic) acid and its salts, and discovered an analytical application of the reaction of trivalent iron and divalent cobalt with thiocyanides (1817–1818). At the same time as J. W. von Goethe, who was investigating sulfur sources at Bad Berka, Grotthuss suggested that sulfur sources in nature were formed as a result of the reduction of gypsum deposits by organic substances (1816). He worked on the analysis of meteorites and proposed original theories of their origins (1819–1821). He first observed the phenomenon of electrostenolysis in passing an electric current through very narrow cracks (1818).

Grotthuss was a very versatile chemist and physicist whose research received well-deserved recognition from his contemporaries, especially in Germany and Russia. He was elected a corresponding member of the Turin and Munich academies of science and an honorary member of the Société Galvanique in Paris. Many of Grotthuss’ ideas contributed to the theoretical development of the kinetic theory, the theory of electrolytic dissociation, the electromagnetic theory of light, and contemporary theories of luminescence.

In the last years of his life Grotthuss’ hereditary illness grew acute; as a result of his great suffering he committed suicide at the age of thirty-seven. He left his estate, archives, and library to found a chair of physics and chemistry at Jelgava, and in his will he freed his serfs from their taxes and obligations.

Grotthuss’ scientific legacy in the field of electrochemistry was “discovered” by Wilhelm Ostwald, who did much to popularize it, at the end of the nineteenth century.

BIBLIOGRAPHY

I. Original Works. Grotthuss’ writings include Physisch-chemische Forschungen (Nuremberg, 1820); and Abhandlungen über Elektrizität und Licht, R. Luther and A. von Oettingen, eds. (Leipzig, 1906), Ostwald’s Klassiker der exacten Wissenschaften, no. 152.

II. Secondary Literature. On Grotthuss or his work, see W. Ostwald, Elektrochemie, ihre Geschichte und Lehre (Leipzig, 1896), pp. 309–316 and passim; J. Stradins, “The Work of Theodore Grotthuss and the Invention of the Davy Safety Lamp,” in Chymia, 9 (1964), 125–145; and Theodor Grotthuss, 1785–1822 (Moscow, 1966).

J. P. Stradins