ti6 A SYSTEM OF 



SECT. CVIIL 



The Eighth Order. 



Zeolites. 



This is defcribed in its indurated ftate, in the 

 Tranfactions of the Academy of Sciences at 

 Stockholm, for the year 1756, and there me- 

 thodifed as a itone/7/ generis^ in regard to the 

 following qualities. 



1. It is a little harder than the fluors, and the 

 calcareous kind : it receives however fcrat- 

 ches from the fteel, but does not flrike 

 fire with it. 



2. It melts eaiily by itfelf in the fire, with a 

 like ebullition as borax does, into a white 

 frothy flag, which not without great dif- 

 ficulty can be brought to a folidity and 

 tranfparency. 



3. It is eafier difibived in the fire by the 

 mineral alcali (falfoda)^ than by the borax 

 and microcolon ic fait. 



4. It does not ferment with this laft fait, as 

 the lime does ; nor with the borax, as thofe 

 of the gypfeous kind. 



5. It diiTolves very (lowly, and without any 

 effervefcence, in acids, as in oil of vitriol 

 and fpirit of nitre. If concentrated oil of 

 vitriol is poured on pounded zeolites, a 

 heat arifes, and the powder unites into a 

 mafs *. 



* Since the publication of this EiTay, there has been dif- 

 covered more varieties of the zeolites, particularly at AdeJfors's 

 gold-mines in Smoland in Sweden, of which fome forts do 

 not melt by themfelves in the fire, but diflblve readily in the 

 acid of nitre, and are turned by it into a firm jelly. E. 



6. In 



