THE MANUFACTURE OF CERTAIN NEW METALLIC ALLOYS
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by Alexander Melville Clark at the Office
of the Commissioners of Patents on the 18th March 1878. A communi-
cation from abroad by Thomas Meiffren and Co., of Marseilles, France.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Mid-
dlesex, Patent Agent. "THE MANUFACTURE OF CERTAIN NEW METALLIC ALLOYS."
[A communication from abroad by Thomas Meiffren and Co., of Marseilles,
France.]
This Invention relates to the production of new metallic alloys suitable as sub-
stitutes for gold and silver in the manufacture of jewellery, and for other similar
purposes.
To make an alloy having the appearance and color of gold I place in a crucible
copper as pure as possible, platinum, and tungstic acid in the proportions below
stated, and when the metals are completely melted I stir and granulate them by
running them into water containing 500 grammes of slaked lime and 500 grammes
of carbonate of potash for every cubic meter of water. This mixture dissolved in
water has the property of rendering the alloy still purer.
I then collect the
granulated metal, dry it, and after having remelted in a crucible I add a certain
quantity of fine gold in the proportion herein-after specified.
An alloy is thus produced, which, when run into ingots, presents the appearance
of red gold of the standard 750/1000, and to which may be applied the name of
aphthite," or unalterable.
"
I may change the color of the alloy by varying the proportions of the different
metals. As flux I use boric acid, nitrate of soda, and chloride of sodium previously
melted together in equal proportions. The proportion of flux to be employed is
25 grammes per kilogramme of the alloy.
The following are the proportions I employ, by preference, for producing an alloy
of red gold color:

page_text: "
Aluminium
Copper-
"
"
The iron and tungsten are melted together, and then granulated, as in the case of
the previous alloy, except that in this instance the water into which the mixture is
run contains one kilogramme of slaked lime and one kilogramme of carbonate of
potash per cubic metre.
The nickel, copper, and aluminium are also melted together and granulated by
running into water containing the same proportion of lime and potash.
Care should be taken during the melting to cover the metals contained in the two
crucibles with a flux composed of one part of boric acid to one part of nitrate of
potash or nitre.
In the crucible containing the aluminium and copper I place a lump of sodium of
about two grammes in weight when treating five kilogrammes of the three metals
(nickel, copper, and aluminium) together to prevent oxidation of the aluminium,
and I also add charcoal to prevent oxidation of the copper. Before granulating the
metal in each crucible it should be well stirred with a fire-clay stirrer.
The granulated metals are dried, ns in the former case, then melted together in
the same crucible in the proportions above indicated, and well stirred, after which
the alloy is run into ingots.
The alloy thus obtained, to which may be given the name of "sideraphthite" (or
unchangeable iron) presents the same white appearance as platinum or silver, and is
not more expensive than German silver.
These improved metallic alloys are capable of resisting the action of sulphuretted
hydrogen, are unattacked by vegetable acids, and but slightly attacked by mineral
acids; they are also perfectly ductile and malleable.