6.
The visibility of gold is worth nil for Nos. I, 5 and 8, are rich in
gold. It has recently been stated that assayers are of no use. We are told we
must be able to see and judge by the eye as to whether a quartz reef
will pay and that it is a poor tale to have it tested. However such
statements are not worth much. If we see the gold and know that it
extends in the quartz, we then know without assay that it will pay and
its extraction may be at once begun with.
Assaying
of fair samples is very necessary. There is not sufficient
sight-evidence of many varieties of quartz to warrant gold being there
in paying quantity. Even the rough amalgamation process, so commonly
used by the miner is unreliable where the gold occurs with pyrites. Nor
can the amalgamation process be successfully used for its extraction
in such cases, e.g., three samples of auriferous pyrites were operated upon not long ago.
(a) From Siberia which contained 100 grams to the ton.
(i) „ Venezuela „ 300 „
(c) „ California „ 150 „
The
first yielded all its gold by amalgamation. The two others, both in the
raw state and after roasting, yielded only insignificant quantities.
From further experiments, it was inferred that the presence of
antimony and arsenic prevent amalgamation.
The
tailings of old mines are now being re-worked by the "Chlorine process"
or by the still better method devised by Mr. W. A. Dixon. See
"Directions for extracting gold, silver, and other metals from pyrites.
Proceedings of the Royal Society, vol. 20."
Ceylon quartz is rather too glassy in appearance, and from many localities is destitute of metal of
any kind, or having caverns either empty or filled with earthy matter.
The pyrites are of too brassy a nature. However, we have quartz
partaking of the character of Nos. 6 and 16 in Hewaheta and Ramboda. A
somewhat similar quartz to 10 and 15 occurs in Balangoda and the
district around.
In
the Nawalapitiya district, we have a quartz partaking of the nature of
II, 12, 13, but no metal is visible. The mineral galena, mispickel and
blende have not been recorded up to the present time as occurring in
this island.
[The above specimens can be seen at the De Soysa Museum.—Ed.]
THE MINERAL RESOURCES OF INDIA, AND THEIR DEVELOPMENT. - By Prok. V. Ball, M.A., F.G.S., Lute of the Geological Survey ef India
I
am not unmindful of the difficulty of the task which I have undertaken,
namely, to endeavour to convey to you, within the limits of a short
paper, a just conception of a very large subject which has manifold
aspects. The more attention and the more time I have devoted to it, the
more impressed have I been with the inapplicability to it of ordinary
generalisations. Indeed, it may be said that any compressed statement
of the facts must of necessity be untrue. It would be convenient, no
doubt, to be able to characterise in a few words the values of the
mineral productions of India, respectively; but what would or might be
true of one part of the country would not be so of others. General
statements have often been published, the effect of which has been,
that a supposed rule has been applied unjustly to particular cases.
Few
have attempted, hitherto, to bring together the information widely
scattered in many publications, in regard to any single mineral
production which is found in India ; and thus the opinions sometimes
expressed as to the value of the diamonds, the coal, the gold, the
copper, or any of the other numerous products, are likely to have been
tinged with the speaker's own particular local experience. You may
often meet with one class of writers or speakers who refer to India as
abounding, or being exceptionally rich, ia valuable
