I 2 95 ] 



above dcfcribed manner (Sett. xxii. et fiq,) it is 

 eafily feen whether it is quickly diflblved, becaufe 

 in that cafe an efFervefcence ariie.% which lads till 

 the whole is diflblved •, or whether this is flowly 

 done, in which cafe few and imall bubbles only 

 rife from the matter : Likewife, it it cannot be 

 diflblved at all, becaufe then it is obferved only to 

 turn round in the flux without the leaft bubble, 

 and the edges .look as fharp as tliey were kefoce. 



SECT. XXVI. 



In order further to illuflrate what has been faid 

 abouc thefe experiments, I will mention lb me 

 inftances out of the Mineralogy, concerning the 

 effects of borax upon the mineral bodies, viz. 



i. The calcareous fubftances, and all thofe 

 Hones which contain any thing of lime in their 

 cornpofition, diflblve readily and with efFervefcence 

 in the borax : This efFervefcence is the more vio- 

 lent, the greater the portion of lime contained in 

 the ftone. This reafon, however, is not the only 

 one in the gypfum, becaufe both the co&itituents 

 of this do readily mix with the borax, and there- 

 fore a greater efFervefcence anfes in melting gyp- 

 fum with the borax, than lime .alone. 



2. The Silicese do not diflblve, unlcfs fome few, 

 which contain a quantity of iron. 



3. The Argiflacea^, when pure, are not acted 

 Upon by the borax •, but when they are mixed with 

 fome heterogeneous bodies, they are diflblved, 

 though very flowly ; fuch is for inftance the Stone 

 Marrow, the Common Clay, tec. 



4. The Granateas, Zeolites, and Trapp, diflblve 

 but flowly. 



5. The Fluores, Afceuinre, and Micacea?, dif- 

 iolve for the mod part very eafllv, and fo forth. 



U 4 ' S E C T. 



