358 



PHYSIOLOGICAL CHEMISTRY. 



a drop of glacial acetic acid to enter from the side and warm 

 gently : abundant crops of hseniin crystals are seen under the 

 microscope. 



3. Add a drop of the fluid to some tincture of guaiacum in a 

 test-tube and float on surface ethereal solution of hydrogen 

 dioxide: a blue ring forms at junction of the ethereal solution 

 and the guaiacum. (Blood is, however, not the only substance 

 showing this reaction.) 



4. The spectroscope shows bands characteristic of haemo- 

 globin. 



Chyle is a white, creamy liquid, of a strongly alkaline reac- 

 tion, having in common with blood the property of coagulating 

 (upon leaving the organism) into white fibrin and turbid serum. 

 The composition of chyle differs according to the state of 

 digestion ; it contains : 



During fasting. 



96.8 percent. 

 0.09 

 2.30 

 0.04 

 0.28 

 0.49 



Lymph is a clear, colorless, or slightly yellow liquid, of a 

 faint alkaline reaction ; in composition it closely resembles 

 chyle but differs from it in containing smaller quantities of 

 fibrin and fatty matters. 



Saliva is secreted by several glands situated in the mouth, and 

 represents in its mixed condition a viscid, generally slightly 

 alkaline liquid of a specific gravity 1.008. It contains of 



Water, 

 Ptyalin, 

 Mucin, 

 Fatty matters, 



Salts, 



99.49 per cent. 

 0.12 " 

 0.13 

 0.11 " 

 0.15 " 



Ptyalin, the active principle of saliva, is a ferment which has 

 the power of converting starch into glucose; its composition is 

 doubtful. Among the various salts of saliva is found potassium 



