PART II 



THE TRANSFORMATION AND SETTING 

 FREE OF ENERGY 



The potential chemical energy of the body substance is 

 changed to kinetic energy (heat and muscular activity) by 

 the physiological combustion. 



The cause of the transformation of energy lies partly in 

 the living substance itself, partly in the stimulations which 

 act upon the living substance. The stimulations either have 

 their origin in the body itself and serve to regulate the rela- 

 tion existing between the individual organs, or they originate 

 in the external world and serve by their stimulating effect 

 to connect the body with its environment. To receive these 

 external stimulations, the body is provided with special 

 organs, the sense organs. The stimulation is carried from 

 the sense organs by means of a special apparatus, the 

 nervous system, to the muscles in which the transformation 

 of energy chiefly takes place. 



The study of the transformation and setting free of energy 

 may be divided into the following chapters : 



1. Animal heat. 



2. Muscular contraction. 



3. Functions of the nervous system. 



4. Functions of the sense organs. 



177 



