A.D. 1805.—Grotthus—Grothuss—(Theodor—more properly Christian Johann Dietrich, Baron von) makes known his theory of electro-chemical decompositions, through the “Mémoire,” etc., published in 12mo at Rome, and of which an English translation appeared in London during 1806.
As Lardner and Fahie have it, Grotthus’ theory was the most plausible of the many proposed at this early period of experimental inquiry to explain chemical decomposition by the voltaic apparatus. The above-named “Mémoire ...” which appeared in the Phil. Mag. for 1806, Vol. XXV. pp. 330–334, is analyzed by both of these writers (Lardner, “Electricity, Mag. and Meteor.,” Vol. I. pp. 135–137, or “Popular Lectures,” 1851, Vol. I. pp. 348, 349; Fahie, “Hist. of Elec. Teleg.,” pp. 210, 211), but it may be briefly stated in the words of Sir David Brewster as follows:
“Grotthus (Annales de Chimie for 1806, Vol. LVIII. p. 61) regards the pile as an electric magnet with attracting and repelling poles, the one attracting hydrogen and repelling oxygen, and the other attracting oxygen and repelling hydrogen. The force exerted upon each molecule of the body is supposed to be inversely as its distance from the poles, and a succession of decompositions and recompositions is supposed to exist among the intervening molecules.”
In this connection it will be well to add here, by way of contrast, and again according to Sir David Brewster, the views held by other experimentalists of the same period. Sir Humphry Davy adopts the idea of attractions at the poles, diminishing to the middle or neutral points, and he thinks a succession of decompositions and recompositions probable. Messrs. Riffault and Chompré regard the negative current as collecting and carrying the acids on to the positive pole, and the positive current as doing the same, with the bases toward the negative pole. Biot attributes the effects to the opposite electrical states of the decomposing substances in the vicinity of the two poles. M. De la Rive considers the portions decomposed to be those contiguous to both poles, the current from the positive pole combining with the hydrogen or the bases which are there present, and leaving the oxygen or acids at liberty, but carrying the substances in union with it across to the negative pole, where it is separated from them, entering the conducting metal, and leaving on its surface the hydrogen or its bases. Faraday regards the poles as exercising no specific action, but merely as surfaces or doors by which the electricity enters into or passes out of the substance undergoing decomposition. He supposes that “the effects are due to a modification of the electric current and the chemical affinity of the particles through or by which that current is passing, giving them the power of acting more forcibly in one direction than in another, and consequently making them travel by a series of successive decompositions and recompositions in opposite directions, and finally causing their repulsion or exclusion at the boundaries of the body under decomposition in the direction of the current, and that, in larger or smaller quantities, according as the current is more or less powerful.”
In 1810 Grotthus published his “Uber d. elektricität ... wassers entwickelt,” one of his curious observations being the fact that when water is rapidly frozen in a Leyden jar, the outside coating, not being insulated, receives a weak electrical discharge, the inside being positive and the outside negative, and when the ice is rapidly thawed, the inside is negative and the outside positive.
References.—Faraday’s “Experimental Researches,” articles 481, 485, 489, 492, 507, etc.; also Phil. Mag., Vols. XXIV. p. 183, and XXVIII. pp. 35 and 59; Joseph Izarn, “Manuel du Galvanisme,” pp. 280–284 for M. Riffault and N. M. Chompré; Whewell, “History of the Inductive Sciences,” Vol. II. p. 304; Noad, “Manual,” pp. 364, 365; William R. Grove, “On Grotthus’ Theory ...” London, 1845; J. S. C. Schweigger’s Journal, Vols. III, IV, IX, XXVIII and XXXI; A. F. Gehlen’s Journal for 1808; L. W. Gilbert’s Annalen der Physik, Vol. LXVII; Ostwald, “Elektrochemie,” 1896, pp. 309–316; A. N. Scherer’s Allgem. nördliche Annal. d. Chemie, Vol. IV; Annales de Chimie, Vol. LXIII; Phil. Mag., Vol. LIX. p. 67; J. C. Poggendorff, “Biog. Literarisches,” etc., Vol. I. pp. 959, 960; “Royal Society Catalogue of Scientific Papers,” Vol. III. pp. 29–31.
Grotthus’ theory was extended by Rudolf Clausius, and the latter’s theory in turn gave way to that of Svante Arrhénius. Clausius maintained that the exchanges were going on continuously, although no current was flowing; while the assumption of Arrhénius was that in every electrolyte, a certain number of molecules break up into ions and that all electrolytes contain some of these free ions. This is the much controverted dissociation theory (Dr. Henry S. Carhart’s Presidential Address).
The “Encycl. Amer.,” New York, 1903, Vol. II says that the establishment of the theory of electrolytic dissociation, which is due to the noted Swedish chemist, Svante Arrhénius, supplies a reasonable explanation of many chemical phenomena otherwise insoluble, and correlates various facts between which no connection was previously discovered. Two important publications by Arrhénius are “Sur la conductibilité galvanique des electrolytes” (1884), and a treatise in German on electro-chemistry (1902). (See “Le Moniteur Scientifique,” Avril 1904, pp. 241–243.)
Rudolf Clausius, German scientist (1822–1888), “one of the most celebrated mathematical physicists of the nineteenth century,” communicated in 1850 to the Berlin Academy of Sciences the paper wherein he announced the second law of thermo-dynamics, that “heat cannot of itself pass from a colder to a hotter body.” The honour of establishing the science of thermo-dynamics upon a scientific basis he thus shares with Rankine and Thomson (“Encycl. Amer.,” Vol. V. n. p.; “New Inter. Encycl.,” New York, 1902, Vol. IV. p. 711. For biography, consult Riecke, “Rudolf Clausius,” Göttingen, 1889; “Meyer’s Konversations-Lexikon,” Leipzig, 1894, Vol. IV. p. 213).
A.D. 1805.—Alexander Tilloch’s Philosophical Magazine, Vol. XXI. p. 279, has a letter addressed by W. Peel to the editor, under date Cambridge, April 23, 1805, relative to the “Production of Muriate of Soda by the Galvanic Decomposition of Water.” This is followed by a communication dated Pisa, May 9, 1805, from Dr. Francis G. Pacchiani, Professor of Philosophy at the Pisa University (Rees’ Encyclopedia, “Galvanism,” p. 15), to Lawrence Pignotti, Historiographer to the King, entitled “Formation of Muriatic Acid by Galvanism,” as well as by two letters, one from W. Peel, dated Cambridge, June 4, 1805, on “The Production of Muriates by the Galvanic Decomposition of Water,” and the other from Dr. Wm. Henry, dated Manchester, July 23, 1805, relative to the above-named processes and to the latter’s own experiments in the same direction.