112 GAI VANIC ELECTRICITY. 



wire, under the same circumstances, would melt, or if 

 too large to undergo fusion, would allow the current to 

 flow readily through it, without that detention which is 

 essential to the production of the above effects, in their 

 highest degree. 



270. If the charcoal points be with- 



How ts the ' , , . -, 



electric flame drawn from each other, a splendid electric 

 produced? flame is p ro d u ced between them. This 

 flame is not the result of combustion, for the char- 

 coal is extremely dense, and wastes away but slow- 

 ly. It is purely electric. Metals melt in it, and are 

 dissipated in vapor. A much larger battery than that 

 here described, is requisite fox the production of ei- 

 ther the light or flame. In experimenting with the 

 compound battery, hereafter described, a slight spark 

 will be observed, on separating the electrodes. 



271. DECOMPOSITION IN THE BATTERY. 

 A decomposition, similar to that of wa- 



in the battery ter and metallic compounds, as above de- 

 scribed, takes place in the battery itself, 

 and seems to be the source of its power. Suppose, for 

 example, the acid with which the zinc and copper are 

 in contact, to be hydrochloric, each molecule of 

 which is composed of an atom of hydrogen and 

 an atom of chlorine. The zinc becomes positive 

 where it is in contact with the acid, and negative at 

 the other end, the extremities assuming different states, 

 as in the case of a piece of soft iron suspended from a 

 magnet. The outer portion of the copper being in con- 

 tact with the negative end of the zinc, is, itself, nega- 

 tive, while the end immersed is positive. The atoms 



