ORGANIC COMPOUNDS 21 



but no J nitrogen the hydrogen and oxygen being 

 in such proportion as to form water, or as 2 to 1, 

 as is shown in the chemic formula for starch, 



Few of the carbohydrates are found in the human 

 body, but are found mostly in the foods we eat. They 

 are the most beneficial nourishment for the mainten- 

 ance of heat and energy, and are, besides, available 

 and easy of digestion. 



The carbohydrates are divided into three groups: 

 (1) Amyloses, including starch, dextrin, glycogen, and 

 cellulose; (2) dextroses, including dextrose, levulose, 

 galactose; (3) saccharoses, including saccharose, lac- 

 tose, maltose. 



1. Amyloses (CeHioOs),,. Starch forms about 10 

 per cent, of the body weight. It is a constituent in 

 wheat, Indian corn, oats, cereals, plants, potatoes, 

 peas, beans, and some fruits. In the presence of a 

 ferment, such as ptyalin in the saliva starch is 

 converted into maltose and dextrose, two forms of 

 sugar. 



Dextrin is a substance formed as an intermediary 

 product in the change of starch into dextrose. It is 

 divided into two varieties erythrodextrin and achro- 

 odextrin 



Glycogen, or animal starch, is a constituent of the 

 animal liver, muscles, arid tissues generally, particularly 

 the tissues of the embryo. 



Cellulose is found mostly in plants. 



2. Dextroses (C 6 Hi 2 O 6 ). Dextrose, glucose, or grape- 

 sugar occurs as irregular, warty masses, usually as a 

 thick syrup. It is a constituent of the vegetable 

 kingdom; generally found with fruit-sugar or levulose 

 in fruits, as grapes, peaches, figs, cherries, mulberries, 

 strawberries, etc. It is also found in honey, and is 

 a normal constituent of liver, blood, and urine in small 

 quantities, in health, and is an indication of the disease 

 diabetes mellitus when found in larger amounts. 



