FOODS 



57 



MEAT 



This is composed of the muscular and connective (including 

 adipose) tissues of certain animals. The flesh of some animals is 

 not eaten ; in some cases this is a matter of fashion ; some flesh, like 

 that of the carnivora, is stated to have an unpleasant taste ; and in 

 other cases (e.g. the horse) it is more lucrative to use the animal as a 

 beast of burden. 



Meat is the most concentrated and most easily assimilable of 

 nitrogenous foods. It is our chief source of nitrogen. Its chief solid 

 constituent is protein, and the principal protein is myosin. In addi- 

 tion to the extractives and salts contained in muscle, there is always 

 a certain percentage of fat, even though all visible adipose tissue is 

 dissected off. The fat-cells are placed between the muscular fibres, 

 and the amount of fat so situated varies in different animals. It is 

 particularly abundant in pork ; hence the indigestibility of this form 

 of flesh ; the fat prevents the gastric juice from obtaining ready 

 access to the muscular fibres. 



The following table gives the chief substances in some of the 

 principal meats used as food : 



Constituents 



Water 

 Sclids 



Proteins, includ- 

 ing gelatin . 

 Fat . 



Carbohydrate 

 Salts . 



The large percentage of water in meat should be particularly 

 noted ; if a man wished to take his daily quantity of 100 grammes 

 of protein entirely in the form of meat, it would be necessary for him 

 to consume about 500 grammes (i.e. a little more than 1 lb.) of meat 

 per diem. 



FLOUR 



The best wheat flour is made from the interior of wheat grains, 

 and contains the greater proportion of the starch of the grain and 

 most of the protein. Whole flour is made from the whole grain 

 minus the husk, and thus contains, not only the white interior, but 

 also the harder and browner outer portion of the grain. This outer 

 region contains a somewhat larger proportion of the proteins of the 



