Eloge of Alexander Volta. JsH 



conviction. Ordinary minds had to demand more explicit proofs. 

 These proofs, in the form of indisputable demonstration, before 

 which all opposition vanishes, Volta found in a capital experi- 

 ment, which I shall now briefly explain. 



Two polished disks of copper and zinc are applied face to 

 face, without any thing between, and attached to insulating 

 handles. By means of these handles, the disks are drawn ra- 

 pidly apart ; they are then presented, one after the other, to the 

 ordinary condensator, provided with an electrometer, and, mark 

 the result, the straws diverge immediately ! By this it is like- 

 wise shewn, that the two metals are in opposite states of elec- 

 tricity, the zinc being positive and the copper negative. By 

 bringing the two disks repeatedly into contact, Volta succeeded, 

 as with an ordinary machine, in producing bright sparks. 



After this experiment, nothing remained to be done regard- 

 ing the theory of galvanic phenomena. The production of elec- 

 tricity by the simple contact of two dissimilar metals, assumed 

 its place among the most important and best established facts in 

 physical science. If at that period any wish regarding it was 

 unsatisfied, it was that ready means might be discovered of in- 

 creasing this kind of electricity. Such means are at the pre- 

 sent day in the hands of every experimenter, and it is to the ge- 

 nius of Volta that we are indebted for the possession of them. 



In the beginning of the year 1800 (the date of such a disco- 

 very ought to be carefully noted), it occurred to the illustrious 

 Professor, in consequence of some theoretical views he entertain- 

 ed, to form a long column, by placing above each other in suc- 

 cession a round plate of copper, another of zinc, and a piece of 

 moist woollen cloth, taking care never to invert this order. 

 What might have been expected a priori from such a combina- 

 tion ? I hesitate not to assert, that this apparently inert mass, 

 this fantastical assemblage, this pile of metallic pieces, separated 

 from each other by a little liquid, forms, with regard to the sin- 

 gularity of its effects, the most wonderful instrument which man 

 has ever invented, without excepting the telescope and the steam- 

 engine. 



I shall be acquitted, I feel assured, of all reproach of exag- 

 geration, if, in the enumeration which I am about to make of 

 Volta's apparatus, I am at the same time permitted to mention 



