northern
provinces of Spain south of the Cantabrian range, which borders on the
Bay of Biscay. Most of the streams in this region mentioned by him
appear to head in the Cantabrian range or in the westward continuation
of the Pyrennees and in that range itself. Mr. Earl also calls
attention to the fact that platinum is present in places in Granada,
east of the Province of Malaga, the scene of the most recent
discoveries.
TASMANIA.
There
is little to say concerning the Tasmanian platinum mines in addition to
the report in Mineral Resources for 1914. It is reported, however,1
that Tasmanian osmiridium, which formerly went to Germany, is now being
refined in the United States, and it is believed that most of the
future output will be refined here.
USES OF PLATINUM.
The
jewelry industry and dentistry apparently consume about equal
quantities of platinum and represent the largest proportion of platinum
used in the United States. There is a considerable consumption in the
manufacture of chemical utensils, including anodes used in the
production of caustic alkali, and of particular importance during the
last two years is the consumption by makers of sulphuric acid.
The
jewelry industry, always more or less influenced by the dictates of
fashion, uses large quantities of platinum and probably has felt the
present stringency more than the industries which put platinum to a
real and necessary use. Platinum makes excellent settings for gems, but
it is believed that this use is not essential and that, so far as
public opinion can be influenced, pressure should be brought to bear to
stop this waste of a metal that is essential in many industries. True,
platinum in jewelry can be recovered, but once in private ownership it
is practically lost to the industry. Platinum is more difficult to work
than gold or some of the white alloys of gold and platinum or of
platinum and palladium, which are also less expensive. It would seem
that some of the more common metals, such as tungsten, molybdenum, or
the chromium-cobalt alloy, stellite, might well be used for jewelry in
place of platinum. These have a silvery-white color, not quite so white
as platinum, and though they do not work as easily as the noble metal
they have possibilities which should be appreciated.
The
manufacturers of platinum for use in dentistry have realized the
importance of finding substitutes for the expensive metal, and the
results of an investigation conducted for the National Dental
Association recently made public2 may be summarized as follows:
The
substitute for platinum must satisfy the following conditions: Its
melting point must be at least well above 1,200° C; it must not be
affected by those chemical compounds formed in its application, nor
should it oxidize at a soldering temperature; it must possess
sufficient strength to resist stresses tending to change its form
while in
1 Commerce Reports, Suppl. 60, p. 8, July 12,1915.
2 Fahrenwald,
F. A., A development of practical substitutes for platinum and its
alloys, with special reference to alloys of tungsten and molybdenum:
Am. Inst. Min. Eng. Bull. 109, pp. 103-149, January, 1916.
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