IO2 



ELEMENTARY PHYSIOLOGY 



fluid secreted in a given time, but after careful experiments 

 and observations it has been estimated that from ten to twenty 

 pints of this fluid are poured into the stomach every twenty-four 

 hours. 



The gastric fluid is a clear and colourless liquid, having a 

 slightly saltish and acid taste. It possesses the power of coagu- 

 lating or curdling albumen, and has antiseptic properties, that is, 



Fig. loo. The Stomach and the Duodenum, laid open to show the 

 Mucous Membrane. 



i, oesophagus ; 2, mucous membrane of the stomach ; 3, pylorus ; 4, duodenum ; 5, the 

 ducts which convey the bile from the liver ; 6, gall-bladder ; 7, common duct ; 8, the 

 pancreatic duct. 



the power of preventing putrefaction. It is on account of this 

 latter property that ' high game ' may be eaten with impunity. 



The composition of the gastric juice is shown in the following 

 table : 



Water 



/Pepsin ....... 



I Common salt ...... 



o , j J Hydrochloric acid 'muriatic acid) 



s 1 Potassium chloride ..... 



Calcium chloride ..... 



Phosphates of calcium, magnesium, and iron 



994 '4 

 3-2 



I'S 



2 



5 

 i 

 i 



Pepsin is the active principle of the gastric fluid. It is a 

 nitrogenous substance which has the power, in the presence of an 

 acid, of dissolving nitrogenous foods. Pepsin may be obtained 



