VOLTA ALESSANDRO: (1745-1827) 'To tell the truth, the author's idea of relating electrical phenomena to chemistry is beautiful, it is great and should lead to truth, but such a conception is singularly contrary to me'

VOLTA ALESSANDRO: (1745-1827) Italian physicist and chemist, a pioneer of electricty and power who is credited with inventing the electric battery and was also the discoverer of methane. An exceptional, lengthy A.L.S., Alessandro Volta, four pages, 4to, Como, 20th January 1775, to a revered colleague, perhaps Carlo Barletti, in Italian. Volta writes an excellent letter of scientific content having received a paper providing the conjectures and details of a discovery made by a professor from Reggio, and detailing his opinion of their work, 'I read with pleasure the paper containing the aforementioned conjectures, which, moreover, seemed to me to be no more than conjectures. To tell the truth, the author's idea of relating electrical phenomena to chemistry is beautiful, it is great and should lead to truth, but such a conception is singularly contrary to me, although I came close to it in my first dissertation "de viribus attractivis fluidi elettrici" which I hope to be able to send you, and in the second "Novus"..... in which I was quite ready to bring into play the mutual forces of the particles of the bodies, these forces not being different from the chemical affinities which, they too, are not mechanical forces..... But I must confess that I would not know how to proceed, not knowing if the author wants to establish three different substances: the volatile elemental fire, the fixed fire, and the electric fire which holds from one and the other, or if he reduces these differences to modifications of one and the same substance. I must make another observation on this subject.....the phenomena do not fit in with the hypothesis....for example the author seems to want to conclude that friction causes the electric fluid to pass from one of the two bodies in which it abounds, to one that possesses little of it.....this is openly contradicted by the facts. Before I had any experience of it I was inclined towards such a hypothesis, believing that glass receives fluid from the hand......because glass by nature lacks electric fluid, and that on the contrary sulphur and resins give fluid to the hand because they are saturated with it. I explained this opinion to Professor P. Maria, who did not agree with me. I myself have since abandoned it for the reasons he gave me and even more so because of my own experiments on silk.....glass does not always receive fluid when rubbed, nor from all bodies. If its surface is made rough, glass will give fluid to the hand or cloth that rubs it, and, even without making it rough, I have observed that it gave fluid if it was rubbed against the back of a living cat......a silk ribbon (I have experienced this several times) will give fluid to a piece of wood or metal that is very smooth, and it will then receive fluid from these same pieces if some rough part is rubbed against it. In short, it is proven that the rough or smooth surface of the same body, combined with other circumstances which do not ensure that this body is more or less full of electric fluid, changes the effects completely. Our burnt woods, in particular, sometimes give and sometimes receive the fluid..... If the author, by saying that friction causes the fluid to pass from a body that has too much of it to one that lacks it, meant a surplus or a lack that is not natural and inherent to the body, but results from the very act of friction; if he meant, I repeat, a surplus or a lack relative to the inequality, resulting from friction itself, in the mutual forces of the particles of the body being rubbed, by setting in motion especially the particles of the surface, by giving them new positions and making them present a new face; if he meant that one can give more or less vigour to the attractive forces of the particles that make up the surface. ...the author would not otherwise be contradicted by the facts exposed, he would even be approaching the explanation I gave in my dissertation. It would then be fairly easy to explain that friction animates the affinities, i.e. brings them into play, but it should be added that it animates them by alternating them, i.e. by strengthening or weakening them with respect to their primitive state.....' Autograph letters of Volta with such fine scientific content are extremely rare and highly desirable. A few very small, extremely minor holes caused by the iron gall ink, otherwise EX

Carlo Barletti (1735-1800) Italian physicist, chair of experimental physics at the University of Pavia from 1772.

Provenance: The present letter is understood to have been a part of the Fatio Collection, which was sold by Maison Charavay of Paris in January and June 1932, at which time it was acquired for the Gentili Collection, which was subsequently sold in Geneva in 1956.