» of Crystals:in:Geodes. 
Even the two new fluids,* recently discovered as Dr. - 
Brewster, i in the cavities of minerals, immiscible as they 
are, and possessed of such remarkable physical , Properties, 
existing in such minute quantities, as to” 
e are not deceived) only by the aid of powerful mi- 
. f 
discovery should lead to the conclusion, that these 
and possibly others meth in minerals, in gery. £0: 
erable quantities. 
_ These reflections were suggested by an accidental ob- 
servation, recently made by Mr. Bennet F. Northrop of 
the senior class in Yale Coline He was occupied in 
breaking. the ballast stones, thrown ashore from a vessel, 
which arrived at this port from New-Orlcans, oh 
Supposed the stones were obtained. They w hiefly 
pebbles, consisting of hornstone, flint, cholcedaeeiaaam 
quartz. Many of them contained cavities lined with crys- 
oy of hyaline quartz. Some of the cavities were occn- 
y half an iol filled ial: rat ‘fluid, re ine very 
the appearance of water, in which magnesia is sus- 
pended. Not expecting such a circumstance, he unfortu- 
eels et the greater part of the mies and before the 
ould be secured, it was ex haled (it being a 
ay) by a rapid seapor leaving a w hite 
le 8 lining the cavity, a staining the sur- 
8 produced y the fracture. While this rapid evapora 
id, jae oiled eye of ‘the observer, occupying not. only 
j of the cavity, but also of the surfaces of the fracture. 
t ascertain- 
oO be silex. They muti ‘effervesced por. di a 
1d when rubbed between " spemgeani : 
of it with great ea zi 
1; ae scrate 
bine asa ile does 
ee Philos, Jour., Vol. ee. 94. 
