CONTENTS. 



PART I. 



Page 

 11 



Vital force, vis vitse, or vitality . 

 Distinction between animal and vegeta- 

 ble life 11 



Assimilation the result of chemical forces 1 2 

 Vitality independent of consciousness . 12 

 Laws of the vital force . . .13 

 Conditions of animal life . . .13 

 Nutrition depends on chemical changes 13 

 Amount of oxygen inspired by an adult 

 man. ...... 14 



It combines with carbon and hydrogen 

 in the body . . . . .14 



The consumption of oxygen varies . 14 

 Effect of heat on these variations. . 15 

 The mutual action of oxygen and car- 

 bon in the body is the true source of 

 animal heat . . " *.. ., . . 15 

 The amount of oxygen regulates that of 



food 16 



Effects of climate on the appetite . 16 

 The process of starvation . . .17 

 Cause of death in starvation and chro- 

 nic diseases . . . . 17 

 Nerves and muscles not the source of 



animal body . . , -.- ' . .18 

 Amount of animal heat . . .19 

 Nervous and vegetative life . . .20 

 Nutrition depends on the constituents . 



of blood 21 



Identity of organic composition infibrme 

 and albumen . . . . .21 



Nutrition in the carnivora the most 

 simple ...... 22 



In the herbivora, depends on the azo- 



tized products of vegetables . . 22 

 These products identical with the con- 

 stituents of blood . . . .22 



The blood of animals is therefore formed 



by vegetables 23 



Uses of the non-azotized ingredients of 

 food . . . . . .23 



Changes of the food in the organism of 

 carnivora . . . . . .t 24 



Carbon accumulates in the bile *-. . 25 

 Nitrogen in the urine . . . .25 



2 



Page 



The carbon is consumed or burned . 26 

 True function of the bile . . ,26 

 Amount of bile secreted . . .27 

 Assimilation more energetic in the 



young animal . . . . .27 

 The butter, sugar, &c., of its food sup- 

 port respiration . . . .28 

 The same is true of the class of herbivora 28 

 Waste of matter very rapid in carnivora 30 

 Importance of agriculture to population 30 

 Assimilation less energetic in the carni- 

 vora 31 



Origin of fat in domesticated animals . 31 

 Its formation is a source of oxygen . 32 

 It is formed when oxygen is deficient, 



and is a source of animal heat . . 33 

 Elements of nutrition and of respiration 35 

 Gelatine incapable of serving for nutri- 

 tion, strictly so called . . .35 

 But it may serve to nourish the gelati- 

 nous tissues 35 



PART II. 



THE METAMORPHOSIS OP TISSUES. 



Discovery of proteine . . . .36 



It is formed by vegetables alone . . 37 

 Theory of chymification . . .37 

 Use of the saliva ... . . .38 



Source of the nitrogen exhaled from 



the lungs and skin . . . .39 

 Composition of proteine . . .41 

 Composition of the animal tissues . 42 

 Gelatine contains no proteine, although 



formed from it 42 



The secretions contain all the elements 



of the blood . . . . .43 

 Formula of blood and metamorphoses 



of bile 44 



Metamorphoses of blood and flesh . 44 

 The constituents of the urine derived 



from the metamorphosed tissues . 45 

 Relation of blood or flesh and proteins 



to the secretions and excretions . 45 

 Formation of gelatine . . . .46 

 Origin of bile in the carnivora . 47 



Origin of bile in the herbivora . 47 



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