Mineralogy and Geology. 139 
cisely what is now taking place at Steamboat springs, where the 
formation of a vein is in progress, and from which currents of boil- 
ing water are often poured forth, whilst at other times the fissures 
give off currents of steam and heated gases only. 
_g- The silica and other substances forming the cementing mate- 
tial of the ancient auriferous river-beds have probably been slowly 
deposited at a low temperature. af : 
€ connection existing between the decomposition of granite 
by the agency of boiling springs, the existence of alkaline plains, 
and the formation of lakes containing various salts of soda and 
potash, is too obvious to require comment. 
» Gold ¢ ; , New a 
on the auriferous quartz veins of Rhinebeck, have recently been 
Se 
S 
Po) 
3 
SS 
$ 
om 
: 
S 
8 
S 
a 
schist in the direction of the cleavage. The quartz is cellular, and 
Town, with oxyd of iron arising fro 
acteristic feature of the whole Appalachian range, and the pres- 
ence of gold here, supplies the link heretofore wanting, 10 the ¢ 
Of the ppalachian gold fields; for there can be no doubt that 
this is a part of the grand belt, taking its rise on the St. Lawrence 
Tiver an scattering its auriferous treasure for thirteen hundred 
nage, along the southeastern border of North America, terminating 
