HISTORY OF CHEMISTRY: Electrochemical Science. Michael Faraday (1791-1867).
The foundation of electro-chemical science may be said to have been laid by Nicholson and Carlisle, who in 1800 discovered the decomposition of water by the agency of the voltaic pile,; but the earliest electro-chemical experiments were those made by Priestley in 1775 upon ammonia gas, and by Deiman and Van Troostwijk in 1789 upon water by means of frictional electricity. Cruickshank by experiments with the chlorides of magnesium, sodium, and ammonium demonstrated that when those salts are decomposed by the electric current, alkali always appears at the negative, and acid at the positive pole.
In 1803 Berzelius and Hisinger published their observations on the electrical decomposition of salts and some of their bases; oxygen, acids, and oxidized bases, they said, appear at the positive pole; combustible bodies, alkalies, and earths at the negative. Later experimenters, however, showed that it is the metal, not the oxide, that appears at the negative pole when salts are electrolysed, and that oxides cannot be supposed to exist ready formed in salts. Davy, whose electrical experiments were commenced in 1800, undertook in 1806 a course of investigations which led him to the discovery of the metals of the alkalies and alkaline earths. In 1807 he expressed the opinion that bodies having an affinity for one anther are in different states of electricity, and "that chemical and electrical attractions depend upon the same cause, acting in the one case on particles and in the other on masses of matter."
In 1834 Faraday discovered that the decompositions effected by the voltaic current indicate the quantity by weight in which the elements combine, or the weights of the atoms of the atomic theory, thus adding to the probability of the correctness of the supposition that the operations of the same agent are exhibited in both chemical and electrical phenomena. Latterly, the discovery of the action of the copper-zinc couple by Gladstone and Tribe has opened out a new filed of electro-chemical research, already productive of important results. To mention, however, the numerous advances that have been made in recent times, whether in chemical physics or in chemistry proper especially as regards the constitution and synthesis of the compounds of carbon would be to exceed the scope of the present introductory notice. The reader must, therefore, be referred to the treatises and original memoirs of those whose labours have effected the modern development of chemistry, and have raised it to the high position which it occupied as a science at the present time. (F. H. B.)
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The above article was written by F.H. Butler, Associate of the Royal School of Mines.