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 d. 1800), who showed that solutions of metallic salts are also decomposed by the current; and William Hyde Wollaston (b. 1766, d. 1828) seized on it as a test of the identity of the electric currents of Volta with those obtained by the discharge of frictional electricity. He found that water could be decomposed by currents of either type, and inferred that all differences between them could be explained by supposing that voltaic electricity as commonly obtained is "less intense, but produced in much larger quantity." Later in the same year (1801), Martin van Marum (b, 1750, d. 1837) and Christian Heinrich Pfaff (b. 1773, d. 1852) arrived at the same conclusion by carrying out on a large scale Volta's plan of using the pile to charge batteries of Leyden jars.

The discovery of Nicholson and Carlisle made a great impression on the mind of Humphry Davy (b. 1778, d. 1829), a young Cornishman who about this time was appointed Professor of Chemistry at the Royal Institution in London. Davy at once began to experiment with Voltaic piles, and in November, 1800, showed that they give no current when the water between the pairs of plates is pure, and that their power of action is "in great measure proportional to the power of the conducting fluid substance between the double plates to oxydate the zinc." This result, as he immediately perceived, did not harmonize well with Volta's views on the source of electricity in the pile, but was, on the other hand, in agreement with Fabroni's idea that galvanic effects are always accompanied by chemical action. After a series of experiments he definitely concluded that "the galvanic pile of Volta acts only when the conducting substance between the plates is capable of oxydating the zinc; and that, in proportion as a greater quantity of oxygen enters into combination with the zinc in a given time, so in proportion is the power of the pile to decompose water and to give the shock greater. It seems therefore reasonable