16 SALIVA. 



(/) The chlorides of sodium and potassium. 



(g) Phosphates, in very small quantities. 



(h) A trace of alkaline sulphates. 



The following statements may suffice in reference to the 

 quantitative relations of the constituents of the parotid secretion : 

 in the parotid saliva of man, Mitscherlich found from 1*468 to 

 1-632$, and Van Setten 1'62 of solid constituents; in that of a 

 dog, Jacubowitsch found only 0'47^ 5 while Gmelin found 2'58# ; 

 in that of the horse Magendie found an average of 1*1 jj ; while, as 

 the mean of six experiments with different specimens of saliva, I 

 determined the solid constituents at 0'708. 



In the human secretion, Mitscherlich found nearly 0'525 of 

 ptyalin associated with an alkali ; in that of the horse, I found on 

 an average 0'140-g- of pure ptyalin (after the extraction of the 

 mineral substances contained in it). 



The alkaline ptyalin obtained from the water-extract and from 

 the spirit-extract insoluble in alcohol, constituted 23'332 of the 

 solid constituents of the saliva of the horse, and yielded 5*675 of 

 ash, which consisted almost entirely of alkaline carbonates and lime. 



The alcohol- extract of the secretion amounted in man, according 

 to Mitscherlich, to about 0'1# ; in that of the horse, I found it 

 amount to 0'0988 . 



The alcohol-extract of the saliva of the horse amounted, ac- 

 cording to the mean of my experiments, to 13*936 of the solid 

 residue, and yielded 3*812# of ash, consisting chiefly of alkaline 

 chlorides. 



No quantitative determination of the sulphocyanide of potas- 

 sium contained in the parotid saliva has yet been attempted. 



In the parotid saliva of the horse, I found 0'0403 of a com- 

 pound of a. fatty acid and potash. 



The ether-extract amounted to 5 *703& of the solid residue, and 

 contained 1'102 parts of potash (as determined by bichloride of 

 platinum from the ash). 



The insoluble matter removed by filtration, and consisting of 

 epithelium with salts, amounted, according to Mitscherlich, to 

 0*005, while I found it as high as 0'124 in the saliva of the horse. 



The insoluble portion of the saliva of the horse consisted, for 

 the most part, of carbonate of lime ; after its abstraction, and that 

 of the ash generally, the insoluble organic matter was very minute; 

 the solid residue contained 17*550^ of insoluble matters, in which 

 were 13'453 parts of ash; hence the epithelium amounted to only 

 only 4'097 of the whole solid residue. 



