160 ALIMENTATION 



Nitrogenous matters .......... 27.60 



Fat . |i .-; . . . .. .--^-."; | Vj " . 15.45 



Saline matters . . . . . . . . , ^ . . . 2.95 



Water . . . . . . .''.'..,' . . 54.00 



100.00 



Bread. Bread presents a considerable variety of alimentary con- 

 stituents and is a very important article of diet. The constituents of 

 flour undergo peculiar changes in panification, which give to good bread 

 its characteristic flavor. Bread, especially coarse brown bread, as a 

 single article of food, is capable of sustaining life for a long time. It 

 contains a large proportion of starch, but its important nitrogenous 

 constituent is gluten, which is not a simple substance but contains vege- 

 table fibrin, vegetable albumins, a peculiar substance soluble in alcohol, 

 called glutin, with fatty and inorganic matters. The following is the 

 composition of bread (Letheby) : 



Nitrogenous matters ' v . . . , * . . . .8.1 



Carbohydrates (chiefly starch) * . 51.0 



Fatty matters . \ .. . * .... 1.6 



Saline matters . . .. r . -.....-; . . . . 2.3 

 Water . . . . .-._,-. > ;.-,. . 37- 



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Potatoes. Potatoes are very useful as an article of diet, especially 

 on account of the agreeable form in which starchy matter is presented ; 

 but they contain a small proportion of nitrogenous matter and do not 

 possess so much nutritive value as bread. They are selected from the 

 vegetable foods for description because they are almost universally used 

 in civilized countries throughout the year. They usually are thoroughly 

 cooked, but the raw potato is a valuable antiscorbutic. The following 

 is the composition of potato (Letheby): 



Nitrogenous matters. . . .."'..* . . . . . 2.1 



Starchy matters . .".'. .. v '. 18.8 



Sugar . . . .,'."." 3.2 



Fat ... - . .. . . . . >:..... . . . 0.2 



Saline matters ., . ' 0.7 



Water . .... . ,*" 75.0 



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Milk. Milk, and articles prepared from milk, such as butter and 

 cheese, are important articles of food. In the treatment of disease, 

 milk frequently is used as a single article of diet. On account of the 

 variety of alimentary matters which it contains, including a great num- 

 ber of inorganic salts and even a small quantity of iron, milk will meet 

 all the nutritive demands, probably for an indefinite time. It is largely 



