MAI!TUAL OF CATTLE-FKEDING, 43 



The eomposltkvi o£ dry starcli is tlie same as tliat of 

 cellulose, viz. : 



Carbon 44.44 



Hydrogen 0. 17 



Oxygen 49.39 



100,00 



In tlie aii*-dry state it contains 12 to 20 per cent, of 

 •water. 



Dextrine seldom lias been found in plants, at least in 

 any considerable quantity, and is eliiefly interesting in tliis 

 connection on accoimt of its relations to stareli and sugar. 



It is prepared commercially in large quantities, imder 

 tbe name of British gum, by the action of dry heat on 

 starch. It is formed in the same way from starch during 

 the baking of bread, and is an important ingredient of 

 food prepared by cooking materials containing starch. It 

 appears to be entirely digestible. 



The Sugars. — There are four principal kinds of sugar, 

 viz. : cane~suga)\ obtained from the juice of the sugar-cane, 

 the sugar-beet, sugai -maple, and other plants, and forming 

 the ordinary sugar of commerce; miU'-sugar, occurring in 

 the milk of mammalia ; and grape-sugar and frmt-stigar, 

 usually occurring together in the juices of plants and sweet 

 fruits and in honey. Grape-sugar is also known as glucose 

 and dextrose, and fruit-sugar as levulose. 



These sugars have the following composition : 





Carbon. 

 Per cent. 



Hydroaren. 

 Per cent. 



Oxygen. 

 Per cent. 



Cane-sugar ) 



Milk sugar S 



Grape-sugar \ 



Fruifc sugar ) 



42.11 

 40 00 



6 43 

 6.67 



51.46 

 63.38 



