270 ELECTRICITY OP THE AIR ; LIGHTNING, 



electricity, which had been drawn into his body, — 

 by the hack-stroke. 



The more electricity a thunder-cloud contains, 

 the nearer it approaches the earth, the moister, 

 and the more conductive the layer of air between 

 them, the more conductive the bodies on the earth 

 may be, and the more perfect their connection 

 with great masses of wet ground, or with running 

 water, — so much the more easily will the electricity 

 of the same kind with that of the cloud be driven 

 away downwards, and the contrary electricity 

 drawn up and gathered together on the surface of 

 bodies ; and, therefore, so much the more likely is 

 the occurrence of an electrical discharge. 



Now, in this discharge, in the passage of the 

 flash, both the electricities play their part alike ; 

 both that which is gathered in the cloud, and that 

 which is opposed to it on the surface of the earth ; 

 and you have just as much reason for saying that 

 the lightning flashes up from the earth to the 

 cloud as that the flash strikes down from the cloud 

 to the earth. In fact, the two pass over to each 

 other ; and where one of them is wanting, where, 

 for instance, a want of conducting power in the 

 bodies on the earth hinders the complete separa- 

 tion of their electricities, a discharge need not be 

 feared. 



If, on the other hand, there is placed among 

 several bodies on the earth, one which is a far 



