71138) 
^5. You offer fome thing that may pertain tothis purpofe in 
yourTra<Stof N. 4P- p. ^82. concerning th§ Generation of 
Chriftal. And I think,I could fliew, by a train or lift of proofs, 
a ftrong probability,that,as Heat vitrifies,fo Durable Frofts^ with 
fomcConcomitants of like naturc^by fomc alternative oppofitions 
of Heate^or perhaps by coincidence of cxtreams>do Chryftallize, 
or more firmly Petrify the moifture or fweat of Rocks and 
Qiiarries, The petrifying fpirit crifpeth by an acuter angle in- 
to afirmer fQlidityjthan canbc performed by any Frofts to us 
known. And the Marcafite is formed by a conftipatijn 
ftronger than that which petrifyeth y and fometimcs where Mar- 
cafices are generated ^ there are found alfo fome parcels of very 
purcfirm, and ponderous Copper, which required a ftrongcr 
Compreffion^jas by an acuter Ac^le, for the Generation of the 
Copper, then for the Generation of the Marcafite is neceffa- 
ry. 
6, And that Frofts alfo alter the Nature of Liquors, we had 
now fome experience in this fnowy feafon : For we faw the water 
of diflblved ^now perform a quick cure, in taking out the 
fire^when the flefli was burnt by a warming pan of Brafsj which 
Metal commonly makes the burning more difficult to be cured ; 
Which did put me in mind , to examine the figures of the ^now, 
which now fell in this extreame Froft, I expefted, that wc 
might fee through the fmall particles, at leaft as through 
Lice,Fleas,CheefeMiiites5&c. by fame kind of tranfparcnce 5 
but I was deceived: My affiftants could make nothing of it , 
either by an ordinary or extraordinary Microfcope. I was in- 
vited to the Inquiry by your N. 3p. p. 774. reporting, that 
in Gerwanj yMzrcb 1666 fir about that time > Snow fell there, 
having the ftiape of Pillars ,fome TetragonaUand fome Hexa- 
gonal^with a neat Bafis, and a larger head, as in Columns.Per- 
haps a more skilful fearch by the beft Microfcopes may di^- 
cover,eitherinwhat fliape the Rorid particles are, when they 
are frozen into 5now, or into what figures or Angles the par- 
ticles of the 5no w are comprcffed by Frofts. If the Clouds were 
continued an intire body of wa(er,they could not quite hinder 
the fight of the 5un and 5tars> for a good depth of Clearwa- 
ter will not hi»dcr it: but the particles, being divided in the 
Clouds 
