Formation of Crystals in Geodes. 285 
matter had concreted into well characterized ‘mammillary 
ce 
“Although we have to regret, that the fluid escaped ex- 
amination, we submit the following conclusions as rhe 
from the facts which have been stated. 
this may be presumed tohate auapderiel in the course “ee 
a long time. 
3dly. Where the crystallization has been rapid, the 
a have been more opaque and dull, and also se 
re slender 4 
‘athly. Under different circumstances, probably where. 
the evaporation was more rapid, the silex has assumed the 
appearance of a dried precipitate mixed, in some cases, 
mith imperfect crystals, 
Sthly. It is at present quite impossible to say what fluid 
laine the solvent, or what imparts to it its extraordinary 
powers, nor is it easy to say, what is become of the fluid, 
in the cavities which | are dry and lined with the spongy 
silicious deposit, or with crystals more or less Sate rae or 
with chalcedony. 
~ In enquiring for parallel cases, we are not able to rect 
tmore than two. We do not consider as parallel the 
of transparent water, or possibly other fluids, occa- 
sionally found in rock crystals, or other stones, nor do we 
tthe microscopic fluids of Dr. Brewster as of this 
is possible that they may prove to be so, but cir- 
ices do not at present appear to justify this conclu- 
“OF the two facts, just now alluded to, one is derived from 
the oral statement of Eli Whitney, Esq. of this city, and 
-is found in the writings of Count Bournon, — 
Mr. Whitney states, that being in Georgia, in the year 
1806, he was i informed of the following facts, and 
as by which they were est blished. OnBriercreek, 
nich passes through haven, and empties 
hree leading from Savan- 
to Augusta, the people were occupied in excava- 
ting a rabeway for A mill; the mill dam was built 
