FATS. CARBOHYDRATES. 13 



rous animals and giving it a reddish yellow color, while 

 biliverdin predominates in the bile of Herbivora which is 

 green. 



Non-Nitrogenous Organic Compounds. These may 

 be conveniently grouped as hydrocarbons or fatty bodies; 

 carbohydrates or amyloids ; and certain non-azotized acids. 



Pats. The fats all contain carbon, hydrogen and oxygen, 

 the oxygen being present in small proportion as compared 

 with the hydrogen. Three fats occur in the body in large 

 quantities, viz. : palmatin (C6iH 9 ' 6 6 ), stearin (C57H U o0 6 ), 

 and olein (C 5 7Hio40 6 ). The two former when pure are 

 solid at the temperature of the Body, but in it are mixed 

 with olein (which is liquid) in such proportions as to be 

 kept fluid. The total quantity of fat in the Body is sub- 

 ject to great variations, but its average quantity in a man. 

 weighing 75 kilograms (105 pounds) is about 2.75 kilo- 

 grams (6 pounds). 



Each of these fats when heated with a caustic alkali, in 

 the presence of water, breaks up into a fatty acid (stearic, 

 palmitic, or oleic as the case may be) and glycerine. The 

 fatty acid unites with the alkali present to form a soap. 



Carbohydrates. These also contain carbon, hydrogen 

 and oxygen, but there is one atom of oxygen present for 

 every two of hydrogen in the molecule of each of thehi. 

 Chemically they arc related to starch; The more impor- 

 tant of them found in the Body are the following: 



Glycogen (C G H 10 05)' found in large quantities in the 

 liver, where it seems to be a reserve of material answering 

 to the starch stored up by many plants. It exists in smaller 

 quantities in the muscles. 



Glucose, or grape sugar (C 6 H ia O), which exists in the 

 liver in small quantities ; also in the blood and lymph. 

 It is largely derived from glycogen which is very readily 

 converted into it. 



Inosit, or muscle sugar (C 6 IIi 2 6 + 2H 2 0), found in 

 muscles, liver, spleen, kidneys, etc. 



Lactose, or sugar of milk (C, a H 3a Ou + H 2 0), found in 

 considerable quantity in milk. 



Organic Non-Nitrogenous Acids. Of these the most 



