322 [Assembly 
plaster, or rather, it was declared to be true plaster, and sold as such. 
It was a gross imposition and fraud upon those who purchased it : for 
it was distinctly pronounced entirely unfit for the purposes of agricul- 
ture, and as being a stone, different in composition from gypsum. 
The Rensselaerite, in colour, varies from nearly a pure white to jet 
black; passing through the several shades of grey, yellowish and 
smoky grey to black. It is soft, and on the surface may be scratched 
by the nail ; the interior is harder. The structure is generally com- 
pact, though sometimes, coarsely fibrous or columnar ; fibres or co- 
lumns diverging from a centre. It is the rock frequently employed 
for inkstands. The white and finely compact variety is a beautiful 
substance when polished ; when cut thin it is translucent and closely 
resembles porcelain. The black variety, also, when polished, is hand- 
some and worthy of a place in a cabinet. This rock is generally associ- 
ated with the primary limestone and serpentine. It hardens by heat 
like the common soapstone for which it had been mistaken, but may 
be employed for the same purposes. It may be easily distinguished 
from it by its hardness ; soapstone or steatite is uniformly soft through- 
out its mass ; whereas, Rensselaerite, though it may be soft on the 
outside, yet, is much harder than steatite on a recent fracture. 
Lying unconformably upon the primary is the Potsdam sandstone. 
It is therefore next in the series. It is a firmer rock, more crystalline 
and less porous than the same rock in St. Lawrence, and especially 
that belonging to Potsdam. It is particularly well characterized on the 
road leading from Carthage to Antwerp. In many places it is broken 
up and fractured ; it everywhere exhibits an abraded surface. The ab- 
rasions furnish many instances in which the rock is worn through ; or 
ground away down to the primary rocks beneath. We have evidence 
of this in the masses of the conglomerate, which is the lower layer, 
still adhering in small masses to the primary, or which are only a few 
feet in diameter; their hardness enabling them to resist the abrading 
action. An instance may be seen near the Oxbow, on the road leading 
to the Pulpit rock ; a remarkable pot hole which has already been 
mentioned. 
This rock furnishes hi no place the vestige of any metalliferous pro- 
duct, except what occurs at its junction Avith the primary ; or it is not 
itself in any portion of the Second Geological District a bearer of the 
metals. It furnishes, however, a valuable building material ; and when 
porous and uncrystalline it is an excellent stone for resisting heat. 
