352 



UTILISATION OF FOOD. 



8*11 potassium chloride, 6*50 sulphuric acid derived from burned proteids, 7*17 



5. In fruits the chief nutrient ingredients are sugar and salts ; the organic acids 

 give them their characteristic taste, the gelatinising substance is the soluble so-called 

 pectin (C S8 H 48 S2 ), which can be prepared artificially by boiling the very insoluble 

 pectose of unripe fruits and mulberries. 



6. Green Vegetables are especially rich in salts, which resemble the salts of the 

 blood : thus, dry salad contains 23 per cent, of salts, which closely resemble the 

 salts of the blood. Of much less importance are the starch, cell-substance, dextrin, 

 sugar, and tbe small amount of albumin which they contain. 



[Vegetables are chiefly useful for the salts they contain, while many of them are antiscor- 

 butic. Their value is attested by the serious defects of nutrition, such as scurvy, which result 

 when they are not supplied in the food. In Arctic expeditions and in the navy, lime juice is 

 served out as an antiscorbutic] 



[Preserved Vegetables. The dried and compressed vegetables of Messrs Chollet & Company 

 are an excellent substitute for fresh vegetables, and are used largely in naval and military ex- 

 peditions.] 



[Utilisation of Food. As regards what percentage of the food swallowed is 

 actually absorbed, we know that, stated broadly, vegetable food is assimilated to a 

 much less extent than animal food in man. Fr. Hofmann gives the following table 

 as showing this : 



235. CONDIMENTS. COFFEE, TEA, ALCOHOL. Some substances are used along with 

 food, not so much on account of their nutritive properties as on account of their stimulating 



