( 4 ) 



Kxpl'icatioti of the caufe of this change — 

 Sulphates of Ihne^ var'ioifly coloured^ and 

 adhering to the decompofed lavas — Iroji^ 

 oxydated^ and modifcd in various manners y 

 the caife of the dijferent colours of the 

 decompofed lavas ^ andfulphates of lime — 

 Difcovery of fever al amorphous and cryf- 

 tallifed zeolites ?iear the ftoves — J^Uy 

 'which they form ivith mineral acids — 

 ILmit bright fafoes ivhen on the point of 

 meltings and fwell confiderahly on their 

 aEiual fufion — 'Terms of co7nparifon be 

 tween thefe %eoUtts and thofe of other 

 countries — Their produSiion not by the dry 

 but the humid ivay — Though the zeolites 

 of fever al volcanized countries are probably 



formed within the fea^ this does not feem 

 to be the origin of thofe of Lipari — ///- 



fiances of zeolites produced in frefJj water 

 — Springs of hot water "which fupply the 

 baths of Lipari — Another prodigious accu - 

 mulation of decompofed lavas ^ and fid- 



phures of lime^ on the fouthern fide of the 

 if and — Perhaps there is no volcanizedcomi- 

 try in Europe where the fulphur eons fnnes 



iffuing 



