CIRCULATION OF DIGESTED FOOD 49 



Composition of Urine of Sheep.' 



Per cent. 



Water 86.48 



Organic matter 7.96 



Inorganic matter 5.56 



The organic matter contained : 



Urea 2.21 



Hippuric acid 3.24 



Ammonia .02 



Other organic substances 2.07 



Carbonic acid .42 



Total 7.96 



The inorganic matter contained : 



Chlorine 1.05 



Potassium chloride 1.84 



Potassium 2.08 



Lime 07 



Magnesia .20 



Phosphoric acid .01 



Sulphuric acid .24 



Silica .07 



Total 5.56 



There is a considerable portion of nitrogenous matter in the 

 urine which is present in the urea and hippuric acid. It must 

 be understood that the composition of the urine is not always 

 constant and it varies with the diet. 



The liver stores up an animal starch (carbohydrate) called 

 glycogen. This is absorbed from the intestine as sugar and 

 changed to starch. It is gradually passed out to the blood as 

 sugar when required. The liver regulates the amount of sugar 

 which should pass into the blood, so much and no more is ad- 

 mitted, the amount varying from' 0.05 to 1.5 per cent. 



The Skin gives off water and other substances by means of 

 the sweat glands. Sweat exists in two forms: viz., the in- 

 visible vapor which is always rising from the surface of the skin, 

 and distinguished as the "insensible perspiration," and the vis- 

 ible material, which is termed "sweat." The insensible per- 



1 Tereg. 



