OF NATURAL PHILOSOPHY. 335 



nothing decisive has been offered on the subject ; 

 and that conjectural modes of action have in this 

 instance too often usurped the place of those to 

 which a careful examination of facts alone can 

 lead us. 



(372.) Philosophers had long been familiar with 

 the effects of electricity above referred to, and with 

 those which it produces in its sudden and violent 

 transfer from one body to another, in rending and 

 shattering the parts of the substances through which 

 it passes, and where in great quantity, producing all 

 the effect of intense heat, igniting, fusing, and vo- 

 latilizing metals, and setting fire to inflammable 

 bodies ; even its occasional influence in destroying 

 or altering the polarity of the magnetic needle 

 had been noticed : but as heat was known to be 

 produced by mechanical violence, and as magnet- 

 ism was also known to be greatly affected by the 

 same cause, these effects were referred rather to 

 that cause than to any thing in the peculiar nature 

 of the electric matter, and regarded rather as an 

 indirect consequence of its mode of action than as 

 connected with its intimate nature. In short, elec- 

 tricity seemed destined to furnish another in addi- 

 tion to many instances of subjects insulated from 

 the rest of philosophy, and capable of being studied 

 only in its own internal relations, when the great 

 discoveries of Galvani and Volta placed a new 

 power at the command of the experimenter, by 

 whose means those effects which had before been 

 crowded within an inappreciable instant could be 

 developed in detail and studied at leisure ; and those 

 forces which had previously exhibited themselves 



