FOODS AND DIET. 211 



TABLE OF PERCENTAGE COMPOSITION OF BEEF, MUTTON, PORK AND 



VEAL (LETHEBY.) 



Water. Albumen. Fats. Salts. 



Beef. Lean, ... 72 19.3 3.6 5.1 



Fat, . . . 51 14.8 29.8 4.4 



Mutlon.Lean, . .72 18.3 4.9 4.8 



Fat, ... 53 12.4 31.1 3.5 



Veal, . . . . 63 16.5 15.8 4.7 



Pork.- Fat, . . .39 9.8 48.9 2.3 



Together with the flesh of the above-mentioned animals, that of the 

 deer, hare, rabbit, and birds, constituting venison, game, and poultry, 

 should be added as taking part in the supply of nitrogenous substances, 

 and also fish salmon, eels, etc., and shell-fish, e.g., lobster, crab, mus- 

 sels, oysters, shrimps, scollops, cockles, etc. 



TABLE OF PERCENTAGE COMPOSITION' OF POULTRY AND FISH. 



(LETHEBY.) 



Water. Albumen. Fats. Salts. 

 Poultry, .... 74 21 3.8 1.2 



(Singularly devoid of fat, and is therefore generally eaten with bacon 

 or pork. ) 



(7.39 consist of non-nitrogenous matter and loss.) (Payen.) 



Even now the list of fleshy foods is not complete, as the flesh of 

 nearly all animals has been occasionally eaten, and we may presume that 

 except for difference of flavor, etc., the average composition is nearly the 

 same in every case. 



II. Milk. Is intended as the entire food of young animals, and as 

 such contains, when pure, all the elements of a typical diet. (1) Albu- 

 minous substances in the form of casein and serum-albumin. (2) Fats 

 in the cream. (3) Carbohydrates in the form of lactose or milk sugar. 

 (4) Salts, chiefly calcium phosphate ; and (5) Water. From it we obtain 

 (a) cheese, which is the casein precipitated with more or less of fat 

 according as the cheese is made of skim milk (skim cheese), or of fresh 

 milk with its cream (Cheddar and Cheshire), or of fresh milk plus 

 cream (Stilton and double Gloucester). The precipitated casein is 

 allowed to ripen, by which process some of the albumen is split up, with 

 formation of fat. (0) Cream, consists of the fatty globules incased in 

 casein, and which being of low specific gravity float to the surface, (y) 

 Butter, or the fatty matter deprived of its casein envelope by the process 



