(i8x) 
brought to him, or which he could colleft. The great 
variety of Shells found either in the neighbouring Hills, 
or brought to him from Malta^ led him into adKpute 
with fome Firtuofi of his acquaintance, concerning their 
Original : Some aflerting that they were formed at firft 
by a piaftical power in the Earth; he on the contrary 
being of Opinion, that they were real Shells thrown by 
an Inundation, at one time or other, upon the Earth ; 
The proving of which Aflcrtion is the fubjeft matter of 
this Treatife. 
After a great deal of prefacing fpent in Verbofe Ci- 
vilities, after the manner of Modern Italian Writers, he 
begins to enquire into the generation of Minerals and 
Metals, which he believes to be generated by a penetra- 
ting Juyce or Vapour arifing out of the Bowels of the 
Eirth, which alters and turns all manner of Earths into 
k feif. So that if in Alum works ( for example ) af- 
ter they are exhaufted, Sand, or Gravel, or Dirt be 
thrown into the Pits from whence the Alum was dug, 
by the penetrative and alterative quality of the Alumi- 
nous Vapour, they will by degrees be changed into fuch . 
a fubflance as had before been dug out of the felf-fame 
place. He fays he has found Clods of Earth and Gravel 
which have been fo put in, which as they have been 
more or lefs diftant from the fountain of Allum, from 
whence thefe Vapours did exhale, were more or lefs im- 
pregnated with Alum : Nay he pretends that by break- 
ing feveral of thefe Clods whilft they were thus digeft- 
ing, he has difcovered theftepsby which Nature works 
in the whole procefs of this Maturation. 
The Foffil Salt in the Mountains of Ragalmuu in Si- 
tih is in his Opinion made after the fame manner; for 
after the Peafants have wrought a Pit, if they jfill it up 
again with the loofe Earth which they find hard by, in . 
a (hort time it will be fb conde nfed and purified, that 
%f: brightnefs it will not be diftinguiihable from that 
whijch:. 
