SOURCES OF TERRESTRIAL ENERGY 



strain when we attempt to move them. Con- 

 versely the molar motions by which our states 

 of feeling are revealed externally, have an en- 

 ergy proportional to the intensity of the feeling ; 

 witness the undulations indicative of pain, which, 

 beginning with a slight twitching of the facial 

 muscles, may end in spasmodic convulsions of 

 the whole body. And of like import is the fact 

 that gentle emotions, like slight electric and nar- 

 cotic stimuli, agreeably quicken the heart's con- 

 tractions ; while violent emotions, suddenly 

 awakened, may stop its beating as effectually as 

 a stroke of lightning or a dose of concentrated 

 prussic acid. 



The bearings of such facts as these upon our 

 theories of mental phenomena will be duly con- 

 sidered in future chapters. At present we have 

 only to regard them as furnishing conclusive evi- 

 dence that the phenomena which are subjec- 

 tively known as changes in consciousness are 

 objectively correlated with molecular motions 

 of nerve-matter which are seen, in an ultimate 

 analysis, to be highly differentiated forms of 

 solar radiance. Waves of this radiance, speed- 

 ing earthward from the sun at the rate of more 

 than five hundred trillions per second, impart 

 their motor energy to the atoms which vibrate 

 in unison in the compound molecules of the 

 growing grass. Cattle, browsing on this grass, 

 and integrating portions of it with their tissues, 

 339 



