202 AGRICULTURAL CHEMISTRY 



taining such a large amount of carbon and small amount 

 of oxygen, fat, when either burned or oxidized as food, 

 produces 2.25 times more heat than the same weight of 

 starch or sugar. One gram of fat yields 9.2 calories, and 

 i pound, 4225 calories. The fact that so much more 

 heat is produced from the oxidation of fat is apparent 

 when the products of oxidation of starch and fat are 

 compared. 



Stearin. 

 C 5 7H 110 6 + 163 O = 57C0 2 + 55H 2 



890 2508 990 



i pound of fat produces 2.8 pounds 

 CO 2 + i.i pounds of water. 



Starch. 



C 6 H 10 5 + 120 = 6C0 2 + 5 H 2 



162 264 90 



i pound of starch produces [.6 



pounds CO 2 + -5 6 pound H 2 O. 



890 parts, by weight, of fat produce, when burned, 2508 

 parts, by weight, of carbon dioxid and 990 parts 

 of water. 162 parts, by weight, of starch produce 

 264 parts, by weight, of carbon dioxid and 90 parts of 

 water. One pound of fat yields 2.8 pounds of carbon 

 dioxid and i.i pounds of water, while one of starch yields 

 i. 6 of carbon dioxid and 0.56 of water. Fat produces 

 approximately 2.25 times more heat than starch. 



271. Amount of Fat in Plants and Foods. The 



amount of fat in various plant substances ranges from a 

 few hundredths of a per cent, in tubers to 35 per cent, 

 and more in flaxseed. Of ordinary grains, oats and corn 

 are the richest in fat and contain from 3.5 to 5 per cent., 

 while wheat and rye have about 2 per cent. each. In 

 hay, the amount of pure fat is less than 2 per cent., and 



