Mineralogy and Geology. 119 
alone fails. The respiration of the miners is a little impeded, but 
work is possible when this limit is not exceeded, provided the tem- 
perature is low. Air collected at Huelgoet, in an unoccupied shaft, 
showed a diminution of 10 per cent. in the amount of oxygen, without 
a replacement of the same by carbonic acid, which circumstance he 
attributes to the influence of decomposing pyrites. ‘i 
34. Bezoardic acid.—This acid according to W6utER, is identical 
with the ellagic acid of Braconnot. 
35. Litharge, (L’Institut, No. 605, p. 276.)—M. F. Lesianc has de- 
termined that oxygen will dissolve in litharge in fusion, in the same 
manner as in silver, without forming a superoxyd ; also that nitrogen 
probably dissolves in a feeble proportion in the same manner. He con- 
cludes also that litharge and red lead differ only physically in structure, 
color and density, but not in composition. 
Il. MineRALOGY AND GEOLOGY. 
86. Cancrinite, Nepheline, and Zircon, from Litchfield, Maine ; by 
Dr. C. T. Jackson, (from the report in the Proceedings of the Geol. 
Assoc., for 1845.)—The Cancrinite was found by Mr. Stacy, in boul- 
ders in granite, associated with Zircon and Nepheline. The masses are 
an inch or more in diameter, with some indications of a rhombohedral 
cleavage. They are translucent, with a deep azure blue color. Hard- 
ness—6 ; specific gravity—=2°420—2-462. The mineral gelatinizes in 
acids quickly. Before the blowpipe it loses its color, becoming trans- 
parent below a red heat; and at a red heat it melts to a colorless glass. 
The Nepheline occurs occasionally in six-sided prisms of a lemon or 
sulphur yellow color, with a vitreous lustre inclining to resinous ; also 
in masses with a somewhat oily lustre and a greenish yellow color, 
(variety Elwolite.) The crystals have the specific gravity 2°42, and 
the Eleolite variety, 2.442. The hardness is 5 to 5:5. 
The following are the analyses of these minerals, by Dr. Jackson : 
Nephel 
; ncrinite. 
Silica, . : ie 35°400 j ‘ j 34°77 
Alumina, < : 31-750 ‘ m : 28-000" 
a OUTST Oe 
Sulphuric acid, - .. 6.460 
Oxydof Manganese, 4.307 Oy Oar 4 87700 
Magnesia, . .- WOR: on ne ee 
Lime, ~~. : “ 1°856 ; . SS ey, (oo 
Water, . . ‘ 08757 : 2 
In the analysis of the Cancrinite, if the sulphuric acid’be regarde: 
as sulphur, it will amount only to 2°592 per cent., and indicates a loss 
of 3°752 per cent. Dr. Jackson states ‘that itis probable that a portion 
of the sulphur must be in a state of sulphuric acid, while another por- 
