342 



FOOD AND DIGESTION 



PERCENTAGE COMPOSITION AND FUEL VALUE PER POUND OF SOME COMMON 

 FOOD STUFFS. (ATWATER AND BRYANT.) 



Meat contains: (i) Muscle proteins, chiefly myosin, blood proteins, colla- 

 gen (from the interstitial fibrous connective tissue), elastin (from the elastic 

 tissue), as well as traces of hemoglobin. (2) Fats, including the lipoids 

 lecithin and cholesterol. (3) Extractives, some of which are agreeable to 

 the palate and others weakly stimulating. These are divided into the 

 non-nitrogenous: glycogen, dextrose, lactic acid, inosit, etc., and into the 

 nitrogenous: consisting chiefly of creatin, and the purine bases. (4) Salts, 

 chiefly chlorides and phosphates of potassium, calcium, and magnesium. 

 (5) Water, the amount of which varies from 15 per cent, in dried bacon to 

 39 in pork, 51 to 53 in fat beef and mutton, and 72 per cent, in lean beef and 

 mutton. 

 TABLE OF PERCENTAGE COMPOSITION OF BEEF, MUTTON, PORK, AND VEAL. 



(L/ETHEBY.) 



