20Q Elements of Mineralogy, 



SPECIES XX. 

 Salt of Sylvius 



Requires about 3 times its weight of water 

 to diflblve it; its fpecific gravity is 1,836; 

 diffolved in nitrous acid it makes aqua regia ; 

 it forms a cloud in the nitrous folution of 

 filver ; fixed alkali precipitate nothing from 

 its folution, nor does a mixture of marine 

 felentine, but the acid of tartar caufes a pre- 

 cipitate. 



loo parts of it contain about 30 of real 

 acid, 63 of vegetable alkali, and y of water. 



It is found in fome boggs in Picardy, and 

 fome mineral waters in Normandy* Monnet 

 Hydrolog. 263* 



SPECIES XXI. 

 Common Salt 



Requires about 2,5 its weight of water to 

 diflblve it in the temperature of 60 ; its fpe- 

 cific gravity is 2,12; the acid of tartar pre- 

 cipitates nothing from it ; in other refpefts it 

 agrees with the above. 



100 parts of it contain 33 real acid, 50 

 of mineral alkali, and 1 7 of water. 



