NITKOGENIZED ALIMENTARY PKINCIPLES. 51 



Vegetable Albumen. In the juice of most vegetables 

 which are used as food, is found a substance, coagulable by 

 heat and by alcohol, and having the same composition as 

 ordinary albumen, with the exception of the equivalents of 

 phosphorus and sulphur. This is found most abundantly in 

 the juice of turnips, carrots, cabbages, and vegetables of this 

 class. In wheaten flour, which contains nearly all classes of 

 alimentary principles, it is also found, but in small quantity. 



There is every reason to suppose that, as nutritive prin- 

 ciples, vegetable and animal albumen are nearly identical. 

 Many of the largest and strongest animals are nourished ex- 

 clusively from the vegetable kingdom. The human subject, 

 and many of the inferior animals, may be nourished at will 

 by vegetable or by animal food. There is, however, always 

 a physiological difference in the various nitrogenized prin- 

 ciples, which is not appreciable by chemical analysis. The 

 flesh of the carnivora, when used as food, is not the same as 

 the flesh of the herbivora ; and the quality of meat may be 

 modified in many animals by changing from a vegetable to 

 an animal diet. Though the muscular tissue of one animal 

 may be used for the nourishment of another, the flesh of an 

 animal thus nourished is not the appropriate food for man. 

 We should live upon vegetable principles ; taking them in 

 part directly, and in part indirectly, or after they have been 

 prepared and assimilated by animals. As a rule, the nutri- 

 tive principles in vegetables are relatively less abundant than 

 in animal food, and the indigestible residue is therefore 

 greater ; but man, and even the carnivorous animals, may 

 be nourished indefinitely by appropriate articles derived from 

 the vegetable kingdom. In man, however, the mental and 

 physical vigor is, as a rule, notably impaired by a strictly 

 vegetable diet. 



Vegetable Fibrin and Caseine. Many of the vegetable 

 juices contain a spontaneously coagulable substance which 

 has been called vegetable fibrin. This is particularly abun- 



