History of the electricity Alessandro Volta pag. 63

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	Alessandro Volta

	Como 18.February.1745-Como 5.March.1827


	Deepenings


	The beginnings of the scientific activity are much premature: also in absence of an university preparation in 1763, to the single ones 18 years, are already in scientific correspondence with the maximum authorities electrical workers of the age, Beccaria father and Nollet Abbot, to which it bravely subjects own theories in matter. The 18 you open them 1769, begins officially with the memory On the attractive force of the fire electrical worker dedicated to Beccaria in form of letter, taking to single twenty-four years the distances from the Italian expert maximum of electricity and proposing a unitary theory of all the phenomena electrical workers on the base of a universal attractive interaction.
	Perhaps here one comes off from the Newtonian gravitational paradigm of the Principia and emphasizes from a part analogies with the pneumatic and the magnetism and from the other leibniziane roots mediated from the Boscovich Jesuit. In 1771, it dedicates to famous the Spallanzani a new memory to epistolary, also this written in Latin, in which it studies the properties electrical workers of the materials and describes a new electrostatic generator. In the June of 1775, it communicates to Priestley the invention of an amazing instrument, the elettroforo perpetual, to its to say test crushing against Beccaria and confirmation of own theoretical views. For the first time the induction came applied to the systematic, abundant and durable production of electricity.

	The elettroforo it is diffused quickly and Time to thirty years becomes famous in all Europe. The searches continue incessant: in a new memory to epistolary, dedicated in date 20 August 1778 to De Saussure, under consideration applies to own theory of atmospheres electrical workers of the “ability” electrical worker of the isolated conductors. Beside the amount and ability concepts, it is here that it uses the tension concept for the first time electrical worker in order to render account of the intensive properties of the electricity. Time means the tension like a tendency to expand itself of the fluid electrical worker, in analogy to the concept of pressure of a gas. In the spring of 1780, it invents the condenser electrical worker, important instrument that it concurs to reveal weakest electric charges. Meantime, continues with experiments and speculations on the possibility to quantify the action of atmospheres electrical workers. 14 March 1782, comes read to the Royal Society a its memory on the condenser. In the definitive version of this memory, it explicitly establishes the tie between charge, ability and tension (Q = CT), a still present law in all the physical witnesses.

	In the 1786, at this point forty-years old one, electrical worker begins to take care itself of meteorology and in relation to this of the quantification and standardization of the tension measures electrical worker, a fundamental problem of the age. The result, published between 1788 and 1789 in a series of six epistolary memories directed to the poet and German scientist Lichtenberg, delineate a solid founded elettrometrico program on two bench marks: the operating definition of an unit standard of tension and the construction of able electro meters of giving comparable indications and linearly proportional them to the applied tensions. But Time was not only taken care of electricity: 3 November of 1776, little after the invention of the elettroforo, discovers the native inflammable air of the swamps, that is methane, and of it studies the properties in a series of seven epistolary memories. In logon with these studies, it invents the gun to inflammable air, little useful like arm, but that someone wants to consider like far progenitor it is of the internal-combustion engine that of the telegraph. Time in fact plans to fill up of hydrogen an appropriate container of glass to gun form sluice from a stopper, and to provoke the outbreak of the gas with a spark (as it happens for the mixture of air and benzine in the cylinders of the motors of our cars). The discharge that provoked the spark could moreover be applied at a distance: a plan quite previewed to make to shoot the “gun” to Milan, with a discharge applied to Como through along conductor suspended on poles (analogies with the telegraph is obvious).

	The untiring Time however is not stopped here: it transforms the gun in a audiometer, an instrument in order to study the “respirabilità”, that is the percentage of deflogistizzata air (oxygen), the air. Experimenting now instead that with methane with the inflammable air of the metals (hydrogen) with to remarkable characterizes it precision in 20%. Moreover premonitory time, in this case directly, the discovery of the composition of the water (hydrogen and oxygen) made from Lavoisier in 1783. In fact or the instrument (the eudiometer) that the method is suggested from Time during its travel to Paris in 1782. It reports in fact to Lavoisier and Laplace that in the eudiometer the combustion of hydrogen and oxygen produces a whitish vapor, than does not identify but with the watery vapor. Time in fact chip ax with delay the proposed chemical revolution from Lavoisier. In 1790 it pushes the perfection of the eudiometer and the eudiometriche measures to a such level that still in 1805 Humboldt and Gay-Lussac they will judge difficultly super skillful. At the same time, dedication under consideration of the gas from the physical point of view and 1793 is reached to late determine the coefficient of expansion to constant pressure of the air with greater precision of that obtained nine years more from Gay-Lussac. In 1794, it executes measures of the vapor tension of the water that anticipate those of Dalton and of new they exceed to them in precision.
	From the beginning of 90 years 'Time is engaged in the debate with Galvani, more exactly from the publication of the De Viribus in 1791. Passed an enthusiasm it begins them, Time becomes critical strongly and, on the contrary of Galvani, it characterizes in the metals the “motors” of the electricity and in the frogs of the simple but sensitive detectors. This interpretation ago to obtain in the 1794 Copley medal from the Royal Society, an acknowledgment between the more withins, the equivalent of what today it is the prize Nobel.
	But Galvani the introduce other experiments that seem to overturn of new the interpretation, to which Time answers at last increasing to the conductors of second class (humid) the laws of the metals, replacing to the frog like detector the electro meter condenser and realizing the battery, initially introduced like “organ artificial electrical worker”, in controversy with the pretension autonomy of the animal electricity. The possibility to produce to electric currents would have changed to science and the technology of the new century. Time as physicist experiences them and inventive of instruments was happening without par, but today it is necessary also to remember its remarkable theoretical contributions (produced of intensive and extensive largenesses, tension, ability, law of the bimetallic contact, atmospheres electrical workers) that, also following a not Newtonian tradition, they were revealed precious for the development of sciences experiences them of the 1800's.