XIV. 



FOODS AND FEEDING 



303 



Ash Constituents of Foods. In addition to the protein, carbo- 

 hydrates and fat, which are usually regarded as the most important 

 constituents of food, the mineral constituents are of great importance 

 to animals. These are often popularly spoken of as "bone formers," 

 but, beyond admitting that a certain proportion of " ash " is necessary 

 in various foodstuffs, little attention has hitherto been paid to this 

 matter. 



The author, from a study of the bones of animals suffering from 

 a disease osteoporosis only too prevalent in the South' African 

 Colonies, has recently 1 called attention to several important matters 

 with reference to the composition as well as the amount of the ash 

 constituents of foodstuffs. 



The ash constituents of the food are utilised in the animal in two 

 ways. 



1. As truly formative materials. The bones, teeth and other hard 

 parts of animals consist largely of phosphates, fluorides, carbonates 



1 See Journal of Comparative Pathology and Therapeutics March, ] 907, pp. 

 35-48 ; Journ. of Agric. Science, 1909 ; Jour. Royal Inst. of Public Health, 1909 ; 

 Seventh Intern. Congress of Applied Chemistry, 1909 ; Illustrated Poultry Eecord, 

 1910 and others. 



