124 



DIGESTION. 



Fig. 24. 



specific gravity of 1005. When first discharged, it is frothy and 

 opaline, holding in suspension minute, whitish flocculi. On being 

 allowed to stand for some hours in a cylindrical glass vessel, an 

 opaque, whitish deposit collects at the bottom, while the supernatant 

 fluid becomes clear. The deposit, when examined by the micro- 

 scope (Fig. 24), is seen to 

 consist of abundant epithe- 

 lium scales from the internal 

 surface of the mouth, de- 

 tached by mechanical irrita- 

 tion, minute, roundish, gra- 

 nular, nucleated cells, appa- 

 rently epithelium from the 

 mucous follicles, a certain 

 amount of granular matter, 

 and a few oil-globules. The 

 supernatant fluid has a faint 

 bluish tinge, and becomes 

 slightly opalescent by boil- 



BCCCAL AND GLANDULAR EPITHELIUM, with g, and by the addition of 

 Granular Matter and Oil-globules; deposited as sedi- nitric acid. Alcohol in 6X- 

 roent from human saliva. n ... 



cess causes the precipitation 



of abundant whitish flocculi. According to Bidder and Schmidt, 1 

 the composition of saliva is as follows : 



COMPOSITION OF SALIVA. 



Water 



Organic matter ......... 



Sulpho-cyanide of potassium 



Phosphates of soda, lime, and magnesia ..... 



Chlorides of sodium and potassium . . 



Mixture of epithelium 



1000.00 



The organic substance present in the saliva has been occasionally 

 known by the name of pty aline. It is coagulable by alcohol, but 

 not by a boiling temperature. A very little albumen is also pre- 

 sent, mingled with the ptyaline, and produces the opalescence 

 which appears in the saliva when raised to a boiling temperature. 

 The sulpho-cyanogen may be detected by a solution of chloride of 

 iron, which produces the characteristic red color of sulpho-cyanide 



1 Verdauungsssefte und Stoffwechsel. Leipzig, 1852. 



