After discussing some of the experiments on nerve stimulation which had been made by Galvani and others, Fabroni argues that these are principally, if not wholly, due to chemical action, and that the undoubted electrical phenomena which sometimes accompany them are not the cause of the muscular contractions. In discussing the nature of the chemical changes produced in two metals by their mutual contact, Fabroni says: 'Since the metals have relationships with each other, the molecules must mutually attract each other as soon as they come into contact. One can not determine the force of this attraction, but I believe it is sufficient to weaken their cohesion so that they become inclined to go into new combinations and to more easily yield to the influence of the weakest solvents.' In order to further show the weakening of cohesion by the contact of two metals, Fabroni describes the results of some experiments which he has made. He says: 'In order to assure myself of the truth of my assumptions, I put into different vessels filled with water: (1) Separate pieces, for example, of gold in one, silver in another, copper in the third, likewise tin, lead, etc. (2) In other similar vessels I put pieces of the same metals in pairs, a more oxidizable and a less oxidizable metal in each pair' but separated from each other by strips of glass (3) Finally, I put in other vessels pairs of different metals which were placed in immediate contact with each other. The first two series suffered no marked change, while in the latter series the more oxidizable metal became visibly covered with oxide in a few instants after the contact was made.' Fabroni found that under the above circumstances his oxidizable metals dissolved in the water, and in some cases salts were formed which crystallized out. He then compares the metals in contact with each other in water with the metals on the tongue when brought into contact, as in Sulzer's experiment, and the two metals touching each other by which different points on a nerve were touched to produce the muscular twitchings in Galvani's experiments, and concludes that the chemical action upon the metals was the same in each case, and that the other phenomena observed must have resulted from this chemical action. It is not strange that when Volta showed later that an electric current passed between the metals in all of tho above cases Fabroni should regard the chemical action which he had previously observed as the cause of this current. Ten years after the publication of Fabroni's original paper, Volta wrote a letter to J. C. Delamethrie which was published in Vol. I of Nicholson's Journal. This letter was written after the chemical changes in the voltaic cell had received a great deal of attention by many experimenters, the most prominent of whom was Davy. To show that Volta's theory as to the source of the current was not affected by these investigations, a quotation from this letter is given below.