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POPULAR SCIENCE REVIEW. 
MINERALOGY. 
Presence of Chabasite in Granite. — The existence of this mineral in 
granite rocks has been pointed out, in a communication from Herr Ulrich, 
to the Natural and Physical Society of Bonn. The chabasite was dis- 
covered in certain cavities of the rocks in which the author had formerly 
discovered calc spar. The discovery is of considerable interest, inasmuch 
as this mineral was never before found in granite. Simultaneously with 
the above discovery, we have to record the discovery of this mineral by 
Rose in the granitic deposits of Connecticut. 
Vanadium in Pig Iron. — In the samples of pig iron from various parts 
of Wiltshire, this mineral has been detected by Mr. Edward Riley. In 
making his analyses of certain specimens, the residue from the silica was 
regarded as titanic acid ; but it was very soon found that this supposition 
was erroneous, for the so-called titanic acid was in reality Vanadium. 
The most effective process for its extraction is the following : — The borings 
are placed in dilute hydrochloric acid, and after the pig is nearly all dis- 
solved, strong acid is added, and the solution is boiled. The chloride of 
iron is then filtered off from the graphite and silica, and the filter is well 
washed from chloride of iron, and treated with a dilute solution of potash 
to dissolve the silica ; the potash is then thoroughly washed out, the filter 
is treated with hydrochloric acid, washed to remove acid, dried, and 
ignited. The residue left is a semi-fused mass, apparently consisting of a 
mixture of a fusible and infusible oxide, which stains a porcelain crucible 
yellow, and adheres strongly to it ; some portions of the mass being of a 
purply blue colour, similar to the bloom on a plum. That this residue is 
vanadium, is proved by the reaction of its solution with various com- 
pounds, and more especially with ferro-cyanide of potassium. — See 
Journal of the Chemical Society , January, 1864. 
Characters of Carphosidcrite. — The characters of this rare mineral have 
been given by M. Pisani, in a memoir presented to the French Academy. 
Carpliosiderite (which was first foun din Greenland, by Herr Breithaupt) 
consists of a sub-sulphate of hydrated peroxide of iron. Mineralogist 
readers, no doubt, remember that when this substance was analysed by 
Harkort, it was stated to have been a phosphate. In its natural condition 
carpliosiderite presents itself in uniform masses of a straw yellow hue, it 
has a 
hardness = 4 
density =* 2’728 
When heated it gives off sulphurous acid, and becomes red. It is insoluble 
in water, but soluble (leaving a residue) in hydrochloric acid ; the solution 
is yellow, and contains iron in large proportion. This mineral contains a 
mixture of gypsum perceptible to the naked eye, and which may be 
washed out with water. The following is the result of an analysis : — 
