170 REPOET OF NATIONAL MUSEUM, 1890. 



the so-called neutral fats, in varying proportions in dif- 

 ferent parts. 



The fats are formed in the body partly from the fatty matter of the 

 food, and partly from the carbohydrates (sugar and starch) and the 

 protein of the food. 



The fats are composed of glycerine combined with a fat-acid from 

 which the fat takes its name, as stearic acid, palmitic acid, oleic acid. 



Composition of Neutral Fats. 



Carbon, 76.5 per cent. 



Oxygen, 12.0 " " 



Hydrogen, 11.5 " " 



(3) Daily income and expenditure of the body. 



OXYGEN OF DAILY INCOME. 

 30.2 OUNCES. 



The total quantity of this gas, 30.2 ounces, is 159 gal- 

 lons. The quantity shown is only one-hundredth of 

 that amount, or 0.3 of an ounce. This oxygen is ob- 

 tained from the air, one-fifth of which is oxygen. 



The oxygen is taken into the lungs and brought in contact with the blood, 

 by which a portion is dissolved and distributed through the body. It is thus 

 brought in contact with the digested food and with the tissues in various parts 

 of the body, and combines with the carbon and hydrogen, forming carbonic 

 acid and water, thus generating heat and muscular energy. 



CARBONIC ACID OF DAILY EXPENDITURE. 



38.8 OUNCES. 



Nearly all the carbon consumed by the body, except 

 the small quantity that passes into urea, combines with 

 oxygen and forms carbonic acid, which is thrown off. 

 The total quantity of this gas, 39 ounces, is about 150 

 gallons. The quantity shown is only one-hundredth of 

 that amount, 0.39 of an ounce. 



Composition of Carbonic Acid Gas. 



In 100 parts. In 38.8 ounces. 

 Carbon, 27.3 10.G 



Oxygen, 72.7 28.2 



