FOOD. 215 



Table of Per-centage Composition of Beef, Mutton, Pork, and Veal. 



(Letheby.) 



Water. Albumen. Fat. Salts. 

 Beef. Lean . 72 19-3 3-6 5.1 



Fat . 

 Mutton. Lean 



Fat 



Veal . 

 Pork. Fat 



51 14-8 29-8 4-4 



72 18.3 4.9 4.8 



53 12-4 31-1 3'5 



63 16-5 15-8 4-7 



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 ahofish salmon, eels, etc., and. shell- fish, e.g., lobster, crab, mussels, 

 oysters, shrimps, scollop, cockles, etc. 



Table of Per-centage Composition of Poultry and Fish. (Letheby.) 



Water. Albumen. Fats. Salts. 

 Poultry 74 21 3 -8 1-2 



(Singularly devoid of fat, and so generally eaten with bacon or pork.) 



White Fish . . . .78 18 -1 2-9 1* 



Salmon . . . .77 16.1 5 -5 1-4 



Eels (very rich in fat) . .75 9-9 13 -8 1-3 



Oysters . . ' . .75-74 11 '72 2-42 2.73 



Even now the list of fleshy foods is not complete, as nearly all animals 

 have been occasionally eaten, and we may presume that the average com- 

 position of all is nearly the same. 



II. MM 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, in small amount, of serum- 

 albumin. (2) Fats in the cream. (3) Carbo-hydrates 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 fat according as the cheese is made of skim milk (skim 

 cheese), 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. (/?) Cream, which consists of the fatty globules in- 

 cased in casein, and which being of low specific gravity float to the surface. 

 (y) fitter, or the fatty matter deprived of its casein envelope by the process 

 of churning. (6) Buttermilk, or the fluid obtained from cream after 



