Trans. N. V. Ae, Sct. 136 Mar. 13, 
cavities are chiefly water and carbon di-oxide, with a small proportion 
of nitrogen. 
I noticed some curious phenomena in a single fragment, which had 
by some means escaped destruction by freezing. 
This specimen had several small cavities, arranged nearly parallel 
to each other. At temperatures below 70° a small bubble could be 
plainly seen to move in each cavity, as the position of the specimen was 
changed. It was further noticed that the cavities contained two 
liquids, in one of which the bubble was wholly confined in its move- 
ments. This was seen to be the central and more transp?rent fluid. 
If this specimen was slightly heated (the mere heat of the hand was 
found sufficient), the bubbles would grow gradually less until they 
disappeared entirely, and the fluids would unite. 
On cooling, a critical temperature would be reached, when all the 
cavities would be filled with numberless minute bubbles, which, rushing 
together, would in a few seconds form to its full size the bubbie origin- 
ally noticed. {found that this experiment could be repeated indefinitely, 
without any diminution of its interesting phenomena or risk of damage 
to the specimen. 
To Alexander county, North Carolina, and to many of the surround- 
ing counties, we can hereafter look to produce fluid-bearing quartz 
crystals second in interest to those of no other region in the world. 
[Mr. HIDDEN’S communication was illustrated with a very striking 
series of inclusion crystals, and of the fragments split off by the frost 
from the large crystals, as described. The pieces were in the form of 
large flakes or plates, parallel to the faces of the rhombohedron, and 
were Clouded and filled with elongated or rod-shaped cavities, in im- 
mense numbers and of conspicuous size. | 
March 13, 1882. 
SECTION OF CHEMISTRY. 
The President, Dr. J. S. NEWBERRY, in the Chair. 
Thirty persons present. 
Prof. D. S. Martin, in behalf of Mr. Kunz, exhibited a series 
of crystals of Diopside, from the town of DeKalb, St. Lawrence Co., 
N. Y. This variety of pyroxene has never before been discovered, it 
is believed, in this country, though long known from the two locali- 
ties of Ala and Traversella, in Piedmont. Its occurrence here is 
therefore, a matter of much interest; and the beauty and transpa- 
