ti 6 ASYSTEMOF 
SECT. CVIII. 
The Eighth Order. 
Zeolites. 
This is defcribed in its indurated ftate, in the 
Tranfaflions of the Academy of Sciences at 
Stockholm, for the year 1756, and there me- 
thod ifed as a ftone ftii 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 Heel, but does not ftrike 
fire with it. 
2. It melts ealily 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 (fal fod^ J, than by the borax 
and microcofmic fait. 
4. It does not ferment with this lafl; fait, as 
the lime does ; nor with the borax, as thofe 
of the gypfeous kind. 
5. It difiblves very fiowly, 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 ElTay, there has been dif- 
covered more varieties of the zeolites, particularly at Adelfors's 
gold-mines in Smoland in Sweden, of which fome forts do 
not melt by themfelves in the fire, but difiblve readily in the 
acid of nitre, and are turned by it into a firm jelly. E. 
6. In 
