Galvanism in the 1820s

A plate entitled “Galvanism” and dated 1820 was published in the 4 th volume of the Supplement to the fourth, fifth, and sixth editions of the Encyclopaedia Britannica, published in Edinburgh in 1824. The plate was part of the article Galvanism, which was written by the French physicist Jean-Baptiste Biot, who began his article with the following words: “The article GALVANISM, in the Encyclopaedia, contains a detailed exposition of a great number of facts, relative to this new and interesting branch of physics. Since the time it appears to have been written, various remarkable phenomena have been brought to light by means of the Voltaic apparatus; and it appears to us, that we are now enabled, as well by the extension of knowledge thence resulting, as by the more profound discussion of the galvanic action itself, to place its theory in a clearer and more determinate point of view, and to combine, in a more philosophical manner, a number of facts, of which a too confined examination had led to inconsistent and contradictory conclusions. Such is the principal object of the supplementary article which we now offer to our readers.” The figures in the plate are described and discussed in the article, which goes from p. 428 to p. 445 of the Supplement.