VOLTA, ALESSANDRO. - Illustrious physicist, from a noble family of Como, b. there on 18 Feb. 1745 and d. there on 5 March 1827.
To him is owed the discovery of the electric current, from which followed most of the modern progress of physics, which in turn transformed, and is still transforming, the standard of living of a great part of humanity. For this reason V. is generally known everywhere as the great discoverer and the first realizer of persistent electric currents by means of the battery he invented in 1799.
In the time of V.'s youth, electricity, rudimentarily known for fully twenty-four centuries, was finally being considered more broadly following Guericke's invention of the first friction machine and its further improvements, which allowed, in a dry atmosphere, an abundant production and collection of it. But while attention was almost generally directed toward the consideration and exaltation of the most conspicuous electrical phenomena, such as long sparks and their various effects, the shock through chains of people holding one another by the hand and the like, the young V., barely eighteen years old, thought that many electrical phenomena must be interpretable by laws analogous to those of Newtonian attraction at very small distances and by contact between different bodies, and in 1763 he communicated this thought of his to the then very well known Abbot Nollet, who praised and encouraged him. It is the thought that much later was to lead him to the battery.
From then on V. proceeded with the criterion of observing, listening, comparing, thinking, before speaking, recalling the Newtonian phrase that discoveries are made by thinking about them; he quietly, in the ancestral home, experimented with very modest means until 1755, that is until his thirtieth year of age, first privately publishing two memoirs respectively addressed to Fr. Giov. Battista Beccaria of the University of Turin and to Abbot Spallanzani of the University of Pavia, and finally constructing the electrophorus, which he immediately (1775) announced and described to C. Priestley of the Royal Society of London. The discovery of the electrophorus is of the highest importance because, as Arago said, under the greatest simplicity and the smallest volume, it offers an inexhaustible vein of electric fluid in any state of the atmosphere. It represents the most elementary of the various influence machines, the only ones still in use today, and all derived from it. This discovery earned V. his appointment as professor of experimental physics in the schools of Como, a post he held until his call to the University of Pavia in 1778. His scientific activity in these two seats, though often interspersed with long journeys for the purpose of establishing instructive contacts with the major scientific personalities and institutions of Europe, was very remarkable. It suffices to recall the discovery of methane gas, the clarification of the concepts of electric capacity and tension, the inventions, besides the already mentioned one of the electrophorus, of the electroscope, of the condensing electrometer, the first true measuring instrument in the field of electrology; his theory on the laws of the dilation of fluids, and in particular of the uniform dilation of air for every degree of temperature, all widely employed everywhere, and bases of further research and progress.
Finally in 1791 the well-known publication of L. Galvani, De viribus electricitatis in motu musculari commentarius, drew V.'s attention to the interesting subject. Applying the criterion of thinking about it, after a few months V. discovered the error of Galvani's theory: it is not a matter of animal electricity, but of metallic electricity, not residing in the nerves of animals, but caused by the different nature of the metals that are placed in contact with one another.
The already glorious V., forty-four years old, finally makes use of the first scientific ideas of the eighteen-year-old, and begins the well-known long polemic with Galvani which, already virtually concluded in favor of V., led him almost inevitably in 1799 (the year following Galvani's death) to the invention of the battery, which he modestly assured he had found on his own path. In fact, certain that the tensions (one would now say the differences of potential) resided in the contacts of heterogeneous metals, he, in the years 1797-99, sought with repeated experiments the way to multiply the metallic pairs (silver and zinc) and to construct a device that would bring the electric tension to a high degree. For this purpose he thought of interposing between the metallic pairs a moist layer, or conductor of the second class, and he was able to observe that the electric tension grew proportionally to the number of pairs. And to this V. alludes when he says: "This is the great step made by me at the end of 1799, a step that soon led me to the construction of the new shocking apparatus," referring to the shocks that he felt in his hands and arms when he touched with both hands the two ends of his device.
Only on 20 March 1800 did V. describe, in the celebrated letter to G. Banks, president of the Royal Society of London, his little machine which resembled in its effects the electric organ of the Raja torpedo. The little machine is called by V. first artificial electric organ, then electromotive apparatus or also column apparatus because of its form at that time. The name battery then prevails, often with the addition of galvanic, used by the French.
The Voltian discovery had a very great echo everywhere and immediately raised the problem "whether the effects of the battery can be explained to us by the new laws of electricity or whether it is necessary for that purpose to admit another particular fluid." And it was again V. who demonstrated the identity of the two fluids, galvanic and electric. On 7 Sept. 1801 at the Institute of France, in the presence of the First Consul Bonaparte, V. demonstrated and discussed his great discovery.
Very recent investigations (Piontelli) have led to the conclusion that the path opened and then followed by V. in his experiments and which led him to decipher the very intricate field of galvanism and to make the marvelous invention spring from it, was not only the sole experimental path of the era, but regains a singular value in the light of modern methodology. Today, after more than a century and a half, one can assert that V.'s ideas, framed within the broader field of energetics, constitute a solid basis of the modern theory of the battery.
Pensioned off at the end of 1804 after thirty years of teaching, V. was successively appointed by Napoleon (king of Italy) a member of the Legion of Honor, senator of the Kingdom and count of the Kingdom of Italy. At the fall of the Kingdom of Italy, after a brief critical period caused by political tumults, although appointed by the succeeding Austrian government director of philosophical studies at the University of Pavia, V. retired to private life between Como and his country residence of Camnago, where his remains rest honored in a specially built little temple.
He was an exemplary Catholic: he attended Mass every day, and on feast days he received the Sacraments; he remained faithful throughout his life to the daily recitation of the Rosary. On festive afternoons he often explained the catechism to the children in his parish church of S. Donnino in Como. In a written declaration of his, requested of him to satisfy the wish of a dying unbeliever, one reads among other things: "I have always held and hold as the one, true and infallible this Holy Catholic Religion, thanking good God endlessly for having infused in me such a faith, in which I firmly propose to live and die with lively hope of attaining eternal life. I recognize it indeed as a gift of God, as a supernatural faith: yet I have not neglected even human means to confirm myself the more in it, to clear away any doubt that might arise to tempt me, studying it attentively in its foundations, tracing through the reading of books both apologetic and contrary the reasons for and against, whence emerge the most valid arguments, which render it most credible even to natural reason, and such that every mind not perverted by vices and passions, every well-ordered mind cannot fail to embrace and love it."