4S3 BIOLOGY, [Book vii. 



numbers, 16,000,000 utilisable kilogramm&tres. But this figui-e 

 is evidently far too high, forasmuch as M. Sanson has not taken 

 into account the dynamic value of the ternary substances con- 

 tained in the ration. 



Among all the alimentary substances which man uses, milk 

 alone, which contains in nearly equal proportions proteic matters, 

 fat and sugar, is a complete aliment ; and if the animals exclu- 

 sively carnivorous nevertheless live, it is because they always 

 find in the body of their prey reserves of fatty and saccharine 

 matters. 



' We have now arrived at the end of our long exposition. The 

 reader will pardon us for having made it especially a long 

 enumeration of facts. Science has in our days abjured the 

 errors of its youth, and nourishes itself with scarcely anything 

 but observations and experiments. Philosophy is on the way to 

 imitate science, of which it is destined one day to be the crown. 

 More and more men are persuaded that without observation and 

 experiment there is no real knowledge. 



To terminate our work it remains for us to say a few words 

 of a vast general theory, now almost everywhere admitted. We 

 mean the general law of balancement between the two organic 

 kingdoms. That there is much truth in this view as a whole 

 cannot be denied. It is certain in a general manner that the 

 vegetal kingdom fabricates the aliments of the animal kingdom. 

 But we must not formulate this proposition too strictly. First of - 

 all we must regard as withdrawn from the law of altemancy the 

 mushroom family on the one hand, and the fauna of the oceanic 

 depths on the other. Moreover, there is no complete antagonism 

 between the vegetal machine and the animal machine. The 

 comburent function does not devolve solely on the animal. The 

 vegetal tissues oxydise themselves like the animal tissues, like 

 everything that lives. 



Finally, the animal likewise fabricates starches and sugars. 



