430 Scientific Intelligence. 
9. Artificial Aventurine ; by MM. Fremy and Cremanpat, (L’Insti- 
tut, No. 624.)—The process for making aventurine has been hitherto a 
secret with the glass establishments at Venice. It has been known that 
the peculiarities of it are due to disseminated erystals of copper. M. 
Fremy, after various experiments, has found that it may be imitated by 
mixing with glass, and heating for some hours, a portion of protoxyd 
of copper and protoxyd of iron. Reaction deoxydizes the copper and 
leaves it in delicate crystalline points; while the iron becomes a per- 
oxyd, and but-slightly tinges the glass with yellow. The specimens thus 
far obtained have a slight opacity, which makes them inferior to the 
Venice aventurine, although similar in other respects. , 
10. Specular Iron artificially produced, (L’Institut, No. 634, Feb. 
1846, p. 72.)—The theory for the formation of crystals of specular 
iron in the fissures of volcanic rocks through the agency of chlorine, 
proposed and explained by Mitscherlich, has been lately confirmed by 
a singular phenomenon at the salt mines of Wieliczka. The support 
ing wood-work through these vast mines was some time since consumed 
by fire, and the iron tubes suffered more or less. After the fire, some 
specimens of saliferous clay were obtained from the parts which had 
_ been exposed to the heat, which were traversed with fissures covered 
with implanted crystals of specular iron. ' : 
11. Bromide and Chloride of Silver in ancient coins, (L’Institut, 
No. 634, Feb. 1846, p. 72.)—M. Bruel of Hanover states, as the re- 
sult of some analyses by him of ancient coins, that they contained 
bromide and chloride of silver. These substances were found to oc- 
cur in the greatest quantity in Greek and Saxon coins of the thir- 
teenth century, but they were detected also in Roman coins. M. 
Bruel suggests that these ingredients may not have existed in the original 
coin, but were received from without while buried. Soe 
Il. MinsraLocy AND GEOLOGY. 
1. On certain Pseudomorphous Crystals of Quartz; by R. W. Fox, 
(Jameson’s Jour. Jan. 1846, p. 115.)—Crystals of quartz are stated by 
Mr. Fox to have been found at the Consolidated mines, in a copper 
vein, which contained regular octahedral pseudomorphous crystals of 
quartz, and others which enclosed a considerable quantity of liquid. 
In two of them, common salt was detected, though but slightly saline to 
the taste. The liquid of others was acrid and contained sulphuric acid, 
iron, muriatic acid, and lime. 
any of these pseudomorphs were more than an inch in diameter, 
and were partly or entirely filled with crystalline quartz; while others 
were empty, or contained more or less numerous fragments of disinte- 
grated fluor. Nearly a hundred such fragments were taken from one of 
