THE GALVANIC CURRENT. 655 



The charge given to the plates of the condenser, if 

 the two copper wires are held by the insulating pieces 

 of sealing-wax, and brought into contact one with the 

 upper, the other with the lower plate, is six times as 

 great as in the first experiment, and consequently the 

 divergence caused by touching the electroscope with 

 one of the condenser plates is now pretty considerable. 



When the two poles of a galvanic circuit, which may 

 consist of one or several cells, are connected by a con- 

 ducting body, the circuit is said to be ' closed,' and in 

 this case the two electricities pass through the connect- 

 ing body and recombine. This movement is called the 

 galvanic current. It resembles the recombination of 

 the two electricities in a Leyden jar or battery of jars, 

 but is very much weaker; but on the other hand it con- 

 tinues as long as the circuit is closed, that is, as long 

 as the poles are in conducting connection, while the 

 discharge current previously considered lasts only for 

 an extremely small fraction of a second. Every electric 

 current is properly speaking a double current : positive 

 electricity flows in one direction, negative electricity 

 flows in the opposite direction. For the sake of clear- 

 ness and brevity, the positive current is designated 

 simply as 4 the current/ if the direction of the current 

 is spoken of, it being always understood that an opposite 

 current, the negative one, exists simultaneously. Thus 

 in one copper-zinc couple we should say, the current 

 flows from the copper pole through the connecting wire to 

 the zinc pole ; or, in other words, positive electricity 

 flows from the copper through the connecting wire to 

 the zinc, and negative electricity flows from the zinc 

 through the connecting wire to the copper. 



As a consequence of the small tension of galvanic 



