ENERGY IN BIOLOGY. IO7 



the beginning of the functional process, and by a 

 necessary effect of that very process, a liberation of 

 chemical energy ; and that can only take place by a 

 decomposition of the immediate principles of the 

 tissue, or, as we may say, by a destruction of organic 

 material. Claude Bernard insisted on this considera-. 

 tion, that the vital function is accompanied by a 

 destruction of organic material. " When a movement 

 is produced, when a muscle is contracted, when 

 volition and sensibility are manifested, when thought 

 is exercised, when a gland secretes, then the substance 

 of the muscles, of the nerves, of the brain, of the 

 glandular tissue, is disorganized, is destroyed, and is 

 consumed." Energetics enables us to grasp the 

 deeply-seated reason of this coincidence between 

 chemical destruction and the functional activity, the 

 existence of which Claude Bernard intuitively sus- 

 pected. A portion of organic material is decomposed, 

 is chemically simplified, becomes less complex, and 

 loses in this kind of descent the chemical energy 

 which it contained in its potential state. It is this 

 energy which becomes the very texture of the vital 

 phenomenon. 



It is clear that the reserve of energy thus expended 

 must be replaced, because the organism remains in 

 equilibrium. Alimentation provides for this. 



How does it provide for it? This is a question 

 which deserves detailed 'examination. We cannot 

 incidentally treat it in full; we can only indicate its 

 main features. 



Hotv the supply of Reserve Stuff is kept up. — We 

 know that food does not directly replace the reserve 

 of energy consumed by the functional activity. It is 

 not its potential chemical energy which replaces. 



