of 0 XFO %S^'S Ht%E. )^ 
they ard more or lels free, they have proportionable trdnlparencj^ 
and fofti hardnefs too ; as the beft of gems, the Diamante evinces. 
And if he (liall ask what Salts are the apteft to perform this feat 
of petrification^ though the difficulty of the qlieftion iliight well 
excufe me, yet Fie venture thus far to give him an anfwer, Thaf 
I have frequently feen at Whitflahle in Kerit') how their Coperas of 
Vitriol is made out of ftones that 'tis more then probable were 
firft made out of that : to the Spirit of which Vitriol if you add 
Oyl of Tartar^ they prefently turn into a fixM and fomwhat hard 
fubftance, not much inferior or unlike to fome incruflations ; 
which feems to conclude, that from thefe two, allfuch Y\Vt con- 
cretions are probably made 5 and that could we but admit that 
Ocean of Tartar^ which Tlato'^ placed in the center of the Earth, 
and thought the origin of all om Springs^ thcbufinefs of petrifi^ 
cations were fufficiently clear. To which I alfo add in the be- 
half of Vitriol^ what's matter of faft, and prevails with me much. 
That where-ever I find ftrong Vitriol Waters, the petrifying ones 
arefeldom far off; which as far as I have obferved, I believe 
may be reduced to thefe three kinds that prefently follow. 
I. Such as purely of thcmfelvesare/f/ri^e^/, the v^ry body 
of water htmgtmntd. into ftone as it drops fromthd 
rocks, which we therefore commonly call Ldpides fill- 
latitios^ and fliall accordingly treat of them in the 
Chapter of Stones^ thefe not ftriftly coming under f e/ri- 
fications^ where bcfide the water and faxeou6 odour ^ there 
is always required a fubjeft to work on of a diftinft 
ffecies from either of the two ; as in 
i^. Such as petrifie by incruftation^-&nA ate only fuperficial, of 
3. Suchzs petrifie per minima^ ot totumper totum ; of both 
which I fliall inftantly treat, but of the laft more at 
large in the following Chapter. 
26, Incruftations^ are petrifications made by fuch waters as let 
fall their ftony particles, which becaufe either of their own big- 
nefs, orclofenefs ofthe/omand texture of the Body on which 
they fall, are fixt only to the fuperficial par ts^ as it were, by ag^ 
gregation^ and do not enter the folid body ; of which I have met 
with feveral in Oxford-Jhire^ and particularly at Sommerton^ as 
was above-mentioned, where the grafs, being one of the fluvia- 
< Anton. Galataut de fiMmlnuni gemrib.u . 
E . • tilia^ 
