189 
Natural History.— Mineralogy. 
Silica, - - s 
- 
- 
51.00 
Lime, 
- 
- 
46.00 
Alumina and Oxide of Iron, 
•- 
- 
1.33 
Water, - - - 
- 
1.00 
Magnesia, a trace* 
99.33 
It is therefore a bisilicate of lime, and its mineralogical formula 
is Cfl S 2 — Amer . Journ. vol. v. p. 114. 
III. NATURAL HISTORY. 
MINERALOGY. 
SO. Analysis of Green Pyroxene . — This mineral accompanies 
the preceding, and was analysed by the same chemist. Specific 
gravity 3.377. 
Silica, 
- 
50.33 
Protoxide of Iron, 
- 
20.40 
Lime, 
- 
19.33 
Magnesia, 
- 
6.83 
Alumina, 
. 
1.53 
Water, 
Protoxide of Manganese a trace, 
0.67 
99.0 
Id. p. 116. 
21. Analysis of Colophonite . — This mineral accompanies the 
preceding, and was analysed by the same chemist. Specific 
gravity 3.896. 
Silica, 
38.00 
Lime, 
. 
29.00 
Protoxide of Iron, 
- 
25.20 
Alumina, 
- 
6.00 
Water, 
- 
0.33 
98.53 
Id. p. 118. 
22. Honourable Mr Knox on the Newry Pitchstone . — The 
pitchstone of Newry in Ireland, described by the Honourable 
G. Knox, in the volume of the Transactions of the Royal So- 
ciety just published, occurs in veins in granite, and, in mine- 
ralogical relations, agrees with the pitchstones of the Island 
of Arran, in the Firth of Clyde. Mr Knox states the fol- 
