24) Eloge of' AUxandej' Volta. 



pile, become, in fact, incandescent in a perfect vacuum. No- 

 thing, therefore, can be incorporated in their substance, and no- 

 thing appears to emanate from them. At the close of an expe- 

 riment, however long continued, the pieces of charcoal are found 

 to be the same in nature and weight as before it began. 



Everyone knows that platina, gold, copper, &c. have no per- 

 ceptible influence on the magnetic needle. Wires of these me- 

 tals attached to the two poles of the pile, are in the same predi- 

 cament, if taken singly ; but the moment they are brought in 

 contact, a very strong magnetic action takes place. Nay, du- 

 ring the whole time they continue in contact, these wires are 

 themselves true magnets ; they charge filings of iron, and com- 

 municate a permanent magnetism to plates of steel placed in 

 their neighbourhood. 



When the pile is very strong, and the wires are at some dis- 

 tance from each other, a bright flame unites their extremities. 

 This light is magnetic; a magnet attracts and repels it. If 

 Franklin and Coulomb, without previous preparation for such a 

 disclosure, were to hear me speak of a flame attractable by a 

 magnet, a lively feeling of incredulity would be the most fa- 

 vourable sentiment with which I could expect to be regarded. 



Let the same wires, at some distance from each other, be 

 plunged into a liquid, into pure water, for example. The water 

 will be instantly decomposed ; the two gaseous elements which 

 form it will be separated ; and the oxygen will be disengaged by 

 the wire attached to the zinc pole, and the hydrogen, remote 

 from that point, by the wire at the pole of copper. In rising 

 to the surface, the globules of gas do not quit the wire by 

 which they were developed ; the two constituent gases may there- 

 fore be collected in two separate vessels. 



When a liquid holding sahne substances in solution, is sub- 

 stituted for water, these substances are analyzed by the pile. 

 The acids are conveyed to the zinc pole, and the alkalies incrust 

 the pole of copper. 



This means of analysis is the most powerful known, and has 

 recently enriched science with a multitude of important results. 

 It is to the pile, for instance, that we owe the decomposition of 

 numerous alkalies and earths, which were previously regarded 

 as simple substances ; it is by the pile that all these bodies are 



