CALORIC AND ELECTRICITY. 445 



forty feet long, was thrown still further, in the 

 same direction, quite into the sea, while many 

 smaller fragments were scattered up and down. 

 (Principles of Geology, vol. i. p. 260.) 



A similar effect of lightning was related, not 

 long since, in the German papers. It was stated 

 that an enormous rock had been removed from 

 the bed of a stream in Prussia, by boring a deep 

 hole in it, into which was inserted a bar of iron 

 twenty-eight feet long. The consequence was, 

 that soon after, during a thunder storm, the 

 lightning was directed to the bar, and the rock 

 shattered to fragments. It would be useless to 

 dwell on the mechanical effects of electricity in 

 rending rocks, trees, buildings, &c. were it not 

 that there are still numerous writers on natural 

 philosophy, who affect to doubt its materiality ; 

 and some who resolve it into undulations of the 

 unknown aether, as if it could not be bottled up 

 in a Leyden battery like water, or any other 

 material fluid, or as if it did not act upon the 

 sense of sight, hearing, feeling, smelling, and 

 even of taste, like other material agents and as 

 if undulations were capable of causing horizontal, 

 vertical, and rotatory motion. 



It was shown in Book II. Chap. ii. that other 

 things being equal, the chemical effects of calo- 

 ric are uniformly in proportion to its absolute 

 quantity. 



It has also been shown by Davy, Children, 



