54 DENTAL TARTAR. QUANTITATIVE ANALYSIS OF SALIVA. [BOOK II. 



It is said that the composition of the tartar of the incisor teeth 

 differs from that of the molar teeth, the latter containing much 

 larger quantities of phosphate of iron and more silica. 



The tartar is as stated above in great part produced by the 

 precipitation of the salts of the saliva ; in part however it is produced, 

 doubtless, by the precipitation of lime and iron salts of the food 

 through the agency of the alkaline phosphates contained in the 

 saliva. 



The following are analyses exhibiting the composition of Tartar 

 (Vergnes 1 ). 



Phosphate of calcium 

 Carbonate 

 Phosphate of iron 

 Silica 



Alkaline salts 

 Organic matter 



Tartar of the 

 Incisor Teeth. 



63-88 



8-48 

 272 

 0-21 



24-69 



62-56 



812 

 0-82 

 0-21 

 014 



27-98 



SECT. 6. DIRECTIONS FOR THE QUANTITATIVE ANALYSIS OF 



SALIVA. 



Collection. When it^ is thought desirable to examine saliva of 



man, care should be taken to collect it an hour or two 

 after a meal, and the precaution should be taken to have the mouth 

 thoroughly rinsed out with water. 



Since the discovery of the powerful sialagogue action of jaborandi 

 and its active principle pilocarpin, a subcutaneous injection of the 

 latter would usually be employed in obtaining saliva from the human 

 subject for analysis. Within ten minutes after such an injection 

 salivation occurs so as to admit of considerable quantities being 

 collected. 



Proceed as directed in Vol. I. p. 26. 



Determina- 

 tion of reac- 

 tion. 



Detennina- This should be effected by means of the bottle (see 

 tion of specific y ol L p . 174). 

 gravity. 



tion of water, Proceed exactly as indicated in the case of blood ; 

 total solids using, however, 20 c.c. of saliva, 

 and salts. 



1 Vergnes, Du tartre dentaire, Paris, 1869, 8vo., quoted by Gautier, Chimie physio- 

 logique, Vol. n. p. 281. 



