( 735 ) 
Italy Cryftals (whieh are a fore of Spars) are produc'd in clear 
evenings by a coagulation of Dew falJing on Nitrous fteauis. 
We have feme of the like rife on Mtfjdip-hills^ our Miners find- 
ing fometimes in roads,vi^here the earth is bare, triangular Crye 
ftals about two inches in length,and an inchover^noc with lharp 
angles, like the Triangular glafs, but wirh round andbluntan- 
gles,and carried up round at the ends like a Coco nut, none of 
. thefe being ever found in digging : I have feen of the fame fore 
which were taken up in Glocejier fiire. So again its commonly 
feen in Grocto*s,that fleams, coagulating waters iffuing from the 
joynts of theclifts, produce Spars of all colours. As to their 
third way of generation, to wit from Earths and Clay s,becaufe 
I do not remember to have met in any Author with afatisfaao- 
ry account thereof, I fball briefly relate to you what I have oh- 
ferv'd herein. 
There are on Mendif-hills^ and generally where Mines are^ 
fubterraneous Vaults or Grotto's, whereof which are pret- 
ty deep, andadmitnotair roofreely,and have other conditions 
requir d, are faid by our Miners to be quick,baving often oar ia 
them, and ftill lively coloured Ear ths, with fome moifture and 
lively Spars : Others, admitting air two or three ways, and ha- 
ving in them black and moift rocks, and dry and rotten llielly 
Srones,dark Earths, barren Sands,and the like, being faid to be 
dead. I have often fearch'd both , and in feme of the formerj 
particularly in one of them, which is 3 5 fathom deep by a per- 
pendicular Line (though the oblique defcent of it makes it a- 
bove 50 fathoms to thofe that go into ir,jIdifcover'd this pro- 
cefs of nature in the formation of SparrThcreare in the bottom 
of this Grotto fome beds of Clay,and others of a Liver-colour'd 
earth, which I take to be as good a Bi?/easany now in ufe 5 it is 
infipid to the tafte,buc fmelis w€ll,erpecially when dry'd 5 for, 
asit liesjitismoiftand like parte, made (b partly by thediftil- 
ling waters,and partly by a fteam incumbent on the place raifed 
from thofe waters by the Mineral ferments. This Earth and Clay 
there flioots up every wherein fpircs in all proportions in 
height, from the firft buddings out of it, till it comes almoft as 
high as a mans finger ; the biggeft of them beirig in thicknefs a- 
bout an inch diameter : Thefe fpires are all rul'd up with irre- 
gular ridges and furro wSjand fome fooner, fome later begin on 
the top to be congealed into Spar^and forgathering a cruft down- 
5 D ward 
