DEATH AND RESURRECTION. 95 



elusions belong to the physical world 

 which is the outer side of matter that 

 faces us. The phenomena that accom- 

 pany combustion belong to this world 

 and are, therefore, strictly speaking, 

 not chemical but physical phenomena. 



But even if these phenomena of light 

 and heat, of which the latter especially 

 interests us here, belong to the world 

 comprehensible to our senses, they 

 must nevertheless be intimately con- 

 nected with the inner chemical process 

 because heat is developed in nearly 

 every chemical reaction. Heat is not 

 created from nothing; there must be 

 a cause for this force, and the cause 

 cannot be anything but the chemical 

 energy which in the chemical process 

 is transformed into heat. In few 

 words: What we generally term com- 

 bustion cannot be identical with the 

 actual chemical process. The light and 

 the heat must, on the contrary, be con- 

 sidered as the external results of the 

 chemical process, its physical effect. 



By a close study of this physical 



