CHAP. I.] QUANTITATIVE ANALYSES OF MIXED SALIVA. 21 



The saliva to be tested is "diluted with five times its volume of 

 water, acidulated with sulphuric acid, and then treated with a solu- 

 tion of the reagent. An intense yellow colour is produced. Griess 

 has by this colorimetric method estimated the nitrous acid to amount 

 to between 1 and 10 milligrammes per litre of saliva. 



The gases The gases of mixed saliva have not been investi- 



of mixed sa*- gated, and from the nature of the fluid they doubtless 

 liva - will vary considerably. We may however conclude that 



they will not sensibly differ in composition from those which may be 

 obtained from the submaxillary saliva. 



Results of Quantitative Analyses of Mixed Human Saliva. 



The following analyses exhibit the results obtained by Frerichs, 

 Jacubowitsch, and Herter 1 : 



(l) (2) (3) 



Frerichs. Jacubowitsch. Herter. 



Water in 1000 pts 99410 99516 994'698 



Solids 5-90 4-84 5'302 



Soluble organic matters ... T42 T34 3'27l 



Epithelium 213 T62 ? 



Potassium Sulpho-cyanate 010 0'06 ? 



Inorganic Salts 219 T82 1-031. 



The following are the results of analyses of the ash of Saliva. 



Jacubowitsch. Enderlin. 

 In 1000 parts of Saliva. 



' (1) (2) Human Saliva. 



Man. Dog. In 100 parts of the Ash. 



Total Salts T82 6'79 Soluble Salts 92'367 



Phosphoric Acid 0'51) n . 89 Insoluble 5'509 



Sodium 0-43J 



Lime 0'03) ftl - \ Alkaline Chlorides ... 61'930 



Magnesia O'OlJ Sodium Phosphates ... 28122 



Alkaline Chlorides... 0'84 5'82 I Sulphate 2*315 



2. PAROTID SALIVA. 

 Introductory Observations. 



The Parotid gland, as has already been stated, is the type of a 

 so-called serous salivary gland, that is, of a gland whose secretory 

 cells are comparatively rich in proteid matters, and which secretes 

 a watery liquid, destitute, or nearly so, of mucin, and containing a 

 trace of a soluble albuminous substance in solution. 



The secretion of parotid saliva is unquestionably related in a 

 peculiarly close manner to the mechanical movements of mastication, 

 as is proved by many facts. In animals with parotid fistulae, the 

 secretion will be observed to flow whenever the muscles of mastica- 

 tion come into action, and the quantity secreted is closely related to 

 1 Hoppe-Seyler, Physiologisclie Cliemie, p. 188. 



