but that there are ftill produced every 
Day ; laftly, that ’tis a thing above 
the power of Man, to difcover a produ¬ 
ction of Glafs without the 
violence of Fite,provided he 
will but let upon an accurate Fke. 
Analyfis of fuch Stones j in 
whofe Cavities the beft Chryftals are 
formed. For 'tis certain, that as Chry^ 
fl:al is concreted in a fluid, fo the lame 
may be refolved into a fluid, if fo be you 
know to imitate the true Diflblvent of 
Nature. Nor is it any matter,that (brae 
Fluid Bodies, when once the refolving 
Fluid or theirMenftruum is thence drawn 
forth,cannot any more be refolved by the 
fame or by the like Kefolventj for that 
happens in Bodies, out of which all the 
Menftruum is refolved by the force of 
Fire i but Chryftal and all Angular Bo¬ 
dies, which do concrete in the midft of 
a rcfolventFluid or Menjiruum, do never 
become fo pure, but that fome Particles 
of the Menjiruum remain betwixt the 
parts of the Angular Body : whence de¬ 
pends the principal cau fe,*that Ghryftal 
The Cauj'e of the difference between Chiyftal nnd Clafsji 
MefraSl'm and $tkr Offratms, 
differs 
