376 
POPULAR SCIENCE REVIEW. 
METALLURGY, MINERALOGY, AND MINING. 
The Dissociation of Gases in Metallurgical Furnaces. — The Comptes 
Rendus for April contains a note by M. L. Cailletet on this subject. In this 
the French savant records some curious experiments, which show that at 
very high temperatures compound gases become separated into their elements, 
and that at such temperature^ these gases have no distinct action on each 
other. He heated metal in a fire of coal and wood-charcoal to such a tem- 
perature that platinum was easily fusible in it. The experiment was con- 
ducted in a porcelain tube, from which the gases were afterwards collected. 
The analyses of these by M. Peligot gave the following results : — 
Oxygen 15 ’24 
Hydrogen 1*80 
Carbonic oxide 2T0 
Carbonic acid 3*0 
Nitrogen 77*86 
100 
These results proved that oxygen has no action upon hydrogen, carbon, or 
carbonic oxide, in the midst of a combustible mass which is maintained at a 
temperature higher than that of the fusing-point of platinum. — Vide Comptes 
Rendus , April 16. 
New Sources of Indium. — The metal indium has, according to a communi- 
cation of Herr Schrotter to the Vienna Academy, been found by Herr Dr. 
Kachler in the zinc-blende of Schonfeld, near Schlaggenwald, where this 
metal occurs, associated with tin ore and other metals, in a bed of steatite, in 
such large proportions that a few grammes of this mineral yield a very 
appreciable quantity of indium. The blende is roasted and then dissolved 
in sulphuric acid ; on treating this solution with metallic zinc, the indium 
and some traces of other metals are precipitated, from which it is afterwards 
separated. 
A lloclase. — A new (?) mineral, to which M. Tschermak has given this 
name, has been found at Oravieza, in the Banat. It is composed of sulphur, 
bismuth, cobalt, and arsenic, in the proportions indicated by the formula 
Co 6 As 5 S 9 , in which it is supposed that one-fourth of arsenic may be replaced 
by an equal quantity of bismuth. It forms rhombohedric crystals of a 
copperish-grey colour, found in calcite, and accompanied with acicular 
arsenical pyrites. Breithaupt has confounded alloclase with glaucodote. — 
Vide The Reader. 
Coal-cutting Machines. — These apparatus, on the utility of which so much 
doubt was entertained on their first appearance, at last begin to be employed. 
One has at last found its way from Leeds, and is now used in the Ne- 
therton Colliery at Northumberland, and is said to be most successful in 
its operation. The motive power is derived from water under pressure, 
natural or artificial. The mode of cutting the coal or shale is novel. It is 
