THE JUICES POURED OUT UPON THE FOOD. 63 



Potassium sulphocyanate is present to the extent of about 

 3 parts in 10,000.! 



Human submaxillary saliva may be obtained in a way 

 similar to that described above for obtaining parotid saliva, 

 namely, insertion of a fine cannula into WHARTON'S duct. 

 When the sublingual gland does not open into the mouth by 

 a separate duct, but discharges its secretion into WHARTON'S 

 duct, the two secretions can be separated by pushing the 

 cannula far enough along the common duct to pass beyond 

 the opening from the sublingual gland. 2 The secretion ob-' 

 tained in this way is clear and watery and of a specific 

 gravity somewhat lower than that of the parotid. It is 

 variously stated to be from 1.0026 to 1.0250, and is subject to 

 considerable variation under physiological conditions. The 

 amount of solids contained in the submaxillary saliva is 

 between 4 and 5 parts in 1000, against 6 to 15 parts found 

 in parotid saliva. The character of the solid constituents 

 is much the same as in the parotid saliva, except sulpho- 

 cyanate, the presence of which is questioned by some authors. 

 Sulphocyanate is certainly present in less amount in the 

 submaxillary secretion than in the parotid. This amount as 

 well as the quantity of submaxillary saliva secreted in any 

 unit of time varies greatly under physiological conditions. 

 Roughly speaking, the total amount secreted in twenty- 

 four hours is three times as great as that secreted by 

 the parotid (OHL,). 3 The reaction is generally stated to 

 be alkaline, more probably, however, it is neutral. The 

 starch-splitting activity of the submaxillary saliva is very 

 :reat. 



OHL seems to be the only investigator who ever obtained 

 luman sublingual saliva in sufficient amount to determine 

 :hat it contains amylase, sulphocyanate, and mucin. 



1 VIERORDT: Tabellen, Jena, 1888, p. 30. 



2 See MOORE: Text-book of Physiology, edited by SCHAEFER, Edin- 

 irgh, 1898, 1, p. 342. 



3 VIERORDT: Tabellen, Jena, 1888, p. 130. 



