E. W. Root on Wilsonite. 47 
€ union of the two images from the two surfaces of the glass 
plate, will be quite undisturbed. It will be apparent that the 
glass slip a 6 may be turned aside, so as not to interfere with the 
use of the instrument asa monocular. I think, however, no 
one who has enjoyed the luxury of binocular vision, so com- 
plete as this is, will be disposed to return to the old form, for 
even with the common glass I have used, I can percieve no de- 
triment to the definition, and but a trifling loss of light. 
Art. VIII.—On Wilsonite from St. Lawrence County, N. Y.; 
by E. W. Boor, 
Unprr the name of Wilsonite, Dr. Sterry Hunt has de- 
scribed, in the Geological Survey of Canada, 1863, a mineral 
from Bathurst, 0. W., which is principally a hydrated silicate 
of alumina and potassa. A short time since I found in the 
cabinet of Prof. Root of Hamilton College, several specimens 
of a mineral from St. Lawrence county, N. Y., resembling in 
appearance the pink scapolite from Bolton, Mass., but easily 
distinguished therefrom, by a much inferior grade of hardness. 
This mineral in its physical properties, action before the blow- 
pipe, and behavior with acids, resembles precisely the wilsonite 
of Hunt. It occurs in peach-blossom red, prismatic masses, 
 ategere. two parallel cleavages at right angles to one another. 
ts hardness is about 3°5. Its specific gravity 2°77-2°78. Its 
luster is vitreous, and in thin fragments it is translucent. Be- 
fore the blowpipe it fuses readily with intumescence to a white 
enamel. Concentrated acids decompose it, the silica separating 
in a pulverulent from, A qualitative analysis gave the same 
components as those of the Canada mineral, silica, alumina, 
lime, magnesia, potassa, soda, and water, with a trace of man- 
ganese. It also contained, quite intimately associated with it, 
some 15 per cent of carbonate of lime. 
_ After removing the carbonate of lime with dilute hydro- 
chloric acid, the mineral gave as the result of a quantitative 
analysis— | 
Sid; 
50; igh. GO KD 
4746 3051 3°63. «S««0'5S OTB 243 G9 = 9943 
