AND ITS SELF-CONSERVATION. 191 



Finally, we must not fail to note,, further, that 

 electricity not only exhibits this two-fold character as 

 electricity, but that its activity constantly develops 

 into both heat and chemical change, just as, on the 

 contrary, both heat and chemical change are accom- 

 panied by electrical excitation. 



In an important sense, then, electricity may be 

 regarded as the higher unity in which heat and chem- 

 ical action molecular repulsion and molecular (or 

 "atomic") attraction combine, the result being, in- 

 deed, a state of very unstable equilibrium. And this 

 corresponds to the general law in nature that the 

 more complex the physical unit the more is it sus- 

 ceptible to dissolution. 



It will be observed that, up to this point, in 

 dealing with "molecular motion," we have had to 

 do with facts that belong definitely to the external 

 or physical world. We come now to consider those 

 phases of molecular motion which are very closely 

 intermingled with factors pertaining to the inner 

 world of mind. This fact gives to the study of those 

 phases a special interest at the same time that it 

 adds greatly to the possibility of error in the re- 

 sults. 



The special phases referred to are 



d. LIGHT AND SOUND. 



As a physical fact, strictly considered, light is insep- 

 arable from radiant heat. And radiant heat is predomi- 

 nantly repulsion a central throbbing that communicates 

 motion outward radially to and through the surrounding 

 medium. 



