XXU CONTENTS. 



These products identical with the constituents of blood ... 47 



The blood of animals is therefore formed by vegetables ... 48 



Uses of the non-azotised ingredients of food ... ... 50 



Changes of the food in the organism of carnivora ... ... 53 



Carbon accumulates in the bile ... ... ... ... 58 



Nitrogen in the urine ... ... ... ... ... 59 



The carbon is consumed or burned ... ... ... ... 60 



True function of the bile ... ... ... ... ... 62 



Amount of bile secreted ... ... ... _,-. . ... 64 



Assimilation more energetic in the young animal ... ... Q7 



The butter, sugar, &c., of its food support respiration ... 68 



The same is true of the class of herbivora ... ... ... 70 



Waste of matter very rapid in carnivora ... ... ... *1Q 



Importance of agriculture to population ... ... ... 77 



Assimilation less energetic in the carnivora ... ... 80 



Origin of fat in domesticated animals ... ... ... 81 



Its formation is a source of oxygen ... ... ... ... 86 



It is formed when oxygen is deficient, and is a source of 



animal heat ... ... ... ... ... ... 88 



Elements of nutrition and of respiration ... ... ... 96 



Gelatine incapable of serving for nutrition, strictly so called 97 



But it may serve to nourish the gelatinous tissues ... ... 98 



PART II. 



THE METAMORPHOSIS OF TISSUES. 



Discovery of proteine ... ... ... ... ... 1 05 



It is formed by vegetables alone ... ... ... ... 106 



Theory of chymification ... ... ... ... ... 108 



Use of the saliva ... ... ... ... ... ...113 



Source of the nitrogen exhaled from the lungs and skin ... 114 



Composition of proteine ... ... ... ... ...121 



Composition of the animal tissues ... ... ... ... 1 25 



Gelatine contains no proteine, although formed from it ... 128 



The secretions contain all the elements of the blood ... A^2 



