{ Children under 14 309
Extractions. { Adults 641
{ Under Nitrous Oxide and Ether 29
Gold Stoppings 45
White Foil ditto 37
Plastic ditto 127
Miscellaneous cases 129
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Total 1,317
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HENRY BROWNE-MASON,
_Hon. Sec._
White Nickel Bronze.
The pure white tint of nickel, its inoxidisability, and, therefore, the
ease with which it is kept clean, have caused it to come into general
use for metal fittings, especially those of vessels and carriages, as
well as for the bright parts of engines and machines. But, on account of
the relatively high price hitherto obtained by nickel, it has been
employed chiefly in the state of electro-deposit.
Nickel-plating is effected by two processes, one hot and the other cold.
In the former a solution of sulphate of nickel is used in an enamel
cast-iron trough. This is the more rapid method, but its results are not
so satisfactory as in the cold process. The latter is effected with a
bath of double sulphate of nickel and ammonia, the articles to be
nickelised being suspended by a platinum wire attached to the positive
pole of the battery, while a plate of pure nickel, to restore the metal
to the bath, is put in connection with the negative pole. The
nickelisation thus produced, though it requires a longer time than the
other process is finer and more durable.
There are, however, several objections to nickel-plating. The process is
injurious to the workmen engaged in it. The thin coating of nickel is
liable to peel off, and in the case of parts exposed to wear, or even
with cleanings, in course of time, the nickel becomes so worn off at the
edges as to expose the base metal beneath. Besides, nickelisation does
not entirely prevent the oxidisation of steel and iron.
A French Company, La Société Française Anonyme de Nickel, briefly
referred to in connection with the Applied Science Exhibition, Paris,
are endeavouring to supersede the nickelisation of brass and copper by
the use of solid nickel bronze, which is thus obtained. The ore,
_garnierite_, extensive deposits of which exist in New Caledonia, the
French penal settlement, is worked by Messrs. John Higginson and Co., of
Noumea, the _concessionaires_. It is by them subjected to a roasting on
preliminary fusion, which forms a regulus, containing from 60 to 70 per
cent. of metallic nickel. This substance is shipped to the works of the
company at Septemes, near Marseilles, where it is smelted into ingots
and granule, containing 99½ per cent, of pure nickel, and ¼ per cent, of
utilisable metallic substances. The extent of the mineral deposits in
New Caledonia, the reduction in the cost of freight owing to the
concentration of metal through the preliminary fusion, and the economy
effected by the new methods of reduction devised by M. Jules Garnier,
enable the company to sell the pure metal at about one-half the price it
obtained three years ago.
For a long time past, efforts have been made to work nickel, but without
success, until the present year, because it was found too brittle; now,
however, pure nickel has been rolled and forged; cups, knives, and other
articles have been formed of it. As a rule, the pure nickel is formed by
the founder with various proportions of copper, zinc, and tin, according
to circumstance, to form nickel bronze; but at least 20 per cent. of
nickel is required to secure inoxidisability, and to give the desired
tint. All articles that are now made of brass or copper nickelised may
be produced in solid white nickel bronze, by the same processes, and
with the same plant, and at practically the same cost; they are also 20
per cent. stronger, so that in many cases they may be made so much
lighter. The great strength and the property of non-oxidisation render
this alloy eminently suitable for mathematical and musical instruments.
A small quantity of nickel added to steel increases its hardness, and
renders it inoxidisable, while edge-tools made of the alloy stand better
than those of ordinary steel. A nickel bell metal is also found to give
good results. The Paris Exhibition of 1878 proved the action of a
totally new system of metallurgy in connection with this beautiful
metal, and that of 1879 showed its practical introduction into most
branches of manufacturing industry.—_Journal of the Society of Arts._