The curious experiment of Galvani in 1790, on the electricity of the muscles of frogs gave a vigor ous impulse to physical inquiry throughout Eu rope. Volta took a deep interest in the new science to which Galvani's experiment has given the name, and he had the good fortune to establish it on a scientific basis, and to extend its bounda ries by the most important discoveries and in ventions. Valli, Fowler, and our countryman Dr. Robison, had preceded Volta in their galvanic in quiries, and the latter had made a slight approach to the invention of the pile, by discovering the sen sation of taste which was excited when the tongue was applied to the edges of a number of plates of zinc and silver placed alternately upon each other.
The first researches of Volta were transmitted to the Royal Society of London, in 1793, in the form of two letters to Mr. Tiberius Cavallo, en titled, .Recount of some discoveries made by M. Gal vani of .Bologna, with experiments and observations on them. Phil. Trans. 1793, vol. lxxxiii. p. 10. These letters contain a perspicuous account of the discoveries of Galvani, with a notice of many curious experiments of his own. He overthrows the opinion of Galvani, that the animal body has an analogy to the Leyden phial; he found that two different metals were necessary to produce the effect; and he concluded that muscular contractions arise from small portions of electricity liberated by the mutual action of the metals. Ile found that the nerve was the organ on which the galvanic in fluence immediately acted, but that, if a part of a muscle be laid upon two different metals, and a communication established between them, a con traction is produced. lie then explains all the phenomena on the principle, that when two metals are brought into contact, a destruction of the elec trical equilibrium takes place, and the one of them gives to the other a portion of its natural elec tricity, the one becoming positive and the other negative. He regards this as a new law of electri city, and he lays claim to the merit of its discovery.
The great discovery of Volta, and that upon which his reputation will always rest, is that of the pile, which is now known by the name of the Voltaic pile. This grand invention was made pre vious to 1800, and having been elected a Fellow of the Royal Society of London, in 1791, lie commu nicated an account in two letters to Sir Joseph Banks, which appeared in the Philosophical Trans actions for that year. In consequence of the war, however, which then raged between England and France, one portion of did paper reached Sir Joseph several months before an opportunity oc curred of sending the remainder. Hence the pub
lication of the invention was delayed; but the ap paratus was constructed in London, and very cu rious experiments were made with it by different gentlemen in that city before the original paper of Volta was laid before the public. This instrument consisted of two perfect and one imperfect con ductor of electricity, viz. silver and zinc, or cop per and zinc, which were the perfect conductors, and a piece of card or leather soaked in salt water, and a little smaller than the metal plates, which formed the imperfect conductor. When one hand was placed on the uppermost conductor, and the other on the lowest, a shock was felt similar to that of the Leyden phial. Its chemical actions were still more important, and are too well known to re quire any notice in this sketch.
In 1821 Volta was invited to Paris. He re peated in the presence of the First Consul, and before the Institute, his experiments with the pile. These experiments were highly successful; and in order to mark an epoch so remarkable in the history of science, that distinguished body pre sented him with a gold medal with this inscription, .4 Volta, la Classe des Sciences Mathematiques et Physiques. In the following year the Institute sent him another, with the inscription .1 Volta, associe etranger; and most of the academies of Europe were proud to enrol his name in time list of' their members.
From Paris Volta repaired to Lyons to assist in the character of deputy from the university of Pa via, at the meeting which was convoked in that city to elect a President of the Italian Republic. When the election was over he was seized with a serious illness, which obliged him to remain some months at Lyons, and afterwards at Geneva, where he experienced the most hospitable reception from the learned professors of that city, with whom he had long been on habits of the most intimate friendship.
The honours which our author thus received in foreign countries were followed by others con ferred upon him at home. He was raised to the rank of a count, and thus became a senator of the kingdom of Italy. In this capacity he was obliged to spend part of the year at Milan, and he re paired every evening to the parties of Paradisi, President of the Academy, at whose house were assembled the most distinguished individuals of the country.