TRANSITION TO CHEMICAL SCIENCE. 113 



we have hitherto given, was never forgotten by 

 the experimenters ; for, in fact, the modes in 

 which electrical currents were excited, were che- 

 mical actions ; the action of acids and metals on 

 each other in the voltaic trough, or in some other 

 form. The dependence of the electrical effect on 

 these chemical actions, and still more, the chemical 

 actions produced by the agency of the poles of the 

 circuit, had been carefully studied; and we must 

 now relate with what success. 



But in what terms shall we present this narra- 

 tion ? We have spoken of chemical actions, but 

 what kind of actions are these ? Decomposition ; 

 the resolution of compounds into their ingredients ; 

 the separation of acids from bases ; the reduction 

 of bodies to simple elements. These names open 

 to us a new drama ; they are words which belong 

 to a different set of relations of things, a different 

 train of scientific inductions, a different system of 

 generalizations, from any with which we have 

 hitherto been concerned. We must learn to un- 

 derstand these phrases, before we can advance in 

 our history of human knowledge. 



And how are we to learn the meaning of this 

 collection of words ? In what other language shall 

 it be explained? In what terms shall we define 

 these new expressions ? To this we are compelled 

 to reply, that we cannot translate these terms into 

 any ordinary language ; that we cannot define 

 them in any terms already familiar to us. Here, as 

 VOL. in. I 



