CHAPTER VI 

 ALIMENTATION 



Hunger and thirst Nitrogenous alimentary substances Non-nitrogenous alimentary sub- 

 stances Carbohydrates Dextrose Levulose Galactose Saccharose Lactose 

 Maltose Starch Glycogen Cellulose, inosite and gums The fats: triolein; tri- 

 palmitin ; tristearin Saponification Emulsification Inorganic alimentary substances 

 Water Sodium chloride Calcium phosphate Iron Alcohol Coffee Tea 

 Chocolate Condiments and flavoring articles The daily ration Necessity of a varied 

 diet Meats Bread Potatoes Milk Eggs. 



IN the organism of animals every part is continually undergoing 

 what may be called physiological wear, or katabolism ; the nitrogenous 

 constituents of the body are being constantly transformed into effete 

 matter; and as these constituents never exist without inorganic matters, 

 with which they are closely and inseparably associated, it is found that 

 the products of their katabolism are always discharged from the body 

 in connection with inorganic substances. This process of molecular 

 change is a necessary condition of life. Its activity may be increased 

 or retarded by various means, but it can not be arrested. The excre- 

 mentitious matters thus formed are produced constantly by the tissues 

 and must be as constantly eliminated. It is evident, from the amount 

 of matter that is daily discharged, that the process of katabolism must 

 be very active. Its constant operation necessitates a constant appropria- 

 tion of new matter by the parts, in order that they may maintain their 

 integrity of composition and be always ready to perform their offices in 

 the economy. The blood contains all the materials necessary for the 

 regeneration of the organism. Its inorganic constituents are found 

 usually in the form in which they exist in the substance of the tissues ; 

 but the organic constituents of the parts are formed in the substance of 

 the tissues themselves, by a transformation of matters furnished by the 

 blood. The physiological wear of the organism is, therefore, being con- 

 stantly repaired by the blood ; but in order to keep the great nutritive 

 fluid from becoming impoverished, the matters which it is constantly 

 losing must be supplied from some source out of the body, and this 

 necessitates the ingestion of articles known as food. Food is taken 

 into the body in obedience to a want on the part of the system, which is 



138 



