CHAPTER XI.

Imitation Silver Alloys.

The undermentioned white alloys have their various uses in the industrial and mechanical arts, some being employed as common silver, whilst others are manufactured as near as possible in imitation of it, and used as a substitute, for many purposes. In melting the alloys in which nickel and several other compounds enter into combination, unless very great care be exercised, it is a difficult matter to maintain the true and definite proportion of each metal of which the alloy proper is composed, owing to the loss of the more fusible metals by volatilization, if allowed to remain too long in the furnace. The best method of preparing the compound for the crucible, is to mix the copper and nickel together. The latter is produced from the pure oxide of nickel; therefore it is taken in this form and placed in the crucible with the copper at the commencement of the operation. When these ingredients are well melted, and incorporated by stirring, add the zinc or other fusible metal required to make up the compound, previously heating it thoroughly over the mouth of the _crucible_, to prevent the chilling of the already molten metal which it contains. When silver forms a component part in any of these alloys it should be added at the beginning of the process along with those of a high degree of fusibility, and reduced under the protection of a suitable flux; charcoal being the best for the purpose. This flux also tends to preserve the fusible metals, upon their addition to the melted compound in the pot, from too suddenly flying away in the shape of fumes. The best zinc of commerce should be employed in these alloys, which is sold under the name of spelter.

Common silver alloy alloy--

oz. dwts. grs. Fine silver 1 0 0 Shot copper 0 17 0 Nickel 0 13 0 ------------- 2 10 0 =============

Another--

oz. dwts. grs. Fine silver 1 0 0 Shot copper 1 0 0 Nickel 0 15 0 ------------- 2 15 0 =============

Common silver alloy--

oz. dwts. grs. Fine silver 1 0 0 Shot copper 1 3 0 Nickel 0 17 0 ------------- 3 0 0 =============

Another--

oz. dwts. grs. Fine silver 1 0 0 Shot copper 1 6 0 Nickel 0 19 0 ------------- 3 5 0 =============

Another--

oz. dwts. grs. Fine silver 1 0 0 Shot copper 1 9 0 Nickel 1 1 0 ------------- 3 10 0 =============

Another--

oz. dwts. grs. Fine silver 1 0 0 Shot copper 1 12 0 Nickel 1 3 0 ------------- 3 15 0 =============

Common silver alloy--

oz. dwts. grs. Fine silver 1 0 0 Shot copper 1 15 0 Nickel 1 5 0 ------------- 4 0 0 =============

Another--

oz. dwts. grs. Fine silver 1 0 0 Shot copper 2 2 12 Nickel 1 7 12 ------------- 4 10 0 =============

Another--

oz. dwts. grs. Fine silver 1 0 0 Shot copper 3 10 0 Nickel 1 10 0 ------------- 5 0 0 =============

Another--

oz. dwts. grs. Fine silver 1 0 0 Shot copper 0 16 0 Nickel 0 10 12 Spelter 0 3 12 -------------- 2 10 0 ==============

Common silver alloy--

oz. dwts. grs. Fine silver 1 0 0 Shot copper 0 19 0 Nickel 0 12 0 Spelter 0 4 0 ------------ 2 15 0 ============

Another--

oz. dwts. grs. Fine silver 1 0 0 Shot copper 1 2 0 Nickel 0 15 0 Spelter 0 3 0 ------------ 3 0 0 ============

Chinese silver--

oz. dwts. grs. Shot copper 1 0 0 Spelter 0 6 0 Nickel 0 4 0 Cobalt 0 3 18 Silver 0 0 18 ------------ 1 14 12 ============

Imitation silver--

oz. dwts. grs. Shot copper 1 0 0 Nickel 0 6 12 Spelter 0 4 18 ------------ 1 11 6 ============

Imitation silver--

oz. dwts. grs. Shot copper 1 0 0 Spelter 0 12 0 Nickel 0 8 0 ----------- 2 0 0 ===========

Another--

oz. dwts. grs. Shot copper 1 0 0 Spelter 0 8 0 Nickel 0 4 0 ----------- 1 12 0 ===========

Another--

oz. dwts. grs. Shot copper 1 0 0 Spelter 0 10 0 Nickel 0 10 0 ----------- 2 0 0 ===========

Another--

oz. dwts. grs. Shot copper 1 0 0 Nickel 0 8 8 Spelter 0 6 16 ----------- 1 15 0 ===========

White alloy--

oz. dwts. grs. Shot copper 1 0 0 Tin 0 10 6 Brass 0 2 12 Arsenic 0 0 18 ------------- 1 13 12 =============

Clark's patent alloy--

oz. dwts. grs. Shot copper 1 0 0 Nickel 0 3 18 Spelter 0 1 22 Tin 0 0 12 Cobalt 0 0 12 ------------- 1 6 16 =============

White alloy--

oz. dwts. grs. Shot copper 1 0 0 Tin 0 10 0 Arsenic 0 1 0 ------------- 1 11 0 =============

Alloy with platinum--

oz. dwts. grs. Fine silver 1 0 0 Platinum 0 5 0 ------------- 1 5 0 =============

Alloy with palladium--

oz. dwts. grs. Fine silver 1 0 0 Palladium 0 5 0 ------------- 1 5 0 =============

The platinum and palladium of which the last two alloys are composed, although very difficult to use in combination with any other metal, readily unite in any proportions with silver; and it has been found that such alloys are not so easily tarnished as the ordinary ones, or even as fine silver itself. These various alloys serve to effect the several purposes for which they are employed in manufactures; wires prepared from any of them will supply the place of silver, as brooch tongs, stems for pins, catches and joints, &c. for articles of common quality and cheap workmanship. They are also employed for preparing the ground for "electro-plate," for which they are very serviceable. When, however, these alloys are employed by the regular silversmith, care should be taken not to get the scraps of metal in any way mixed with those of the better material, otherwise difficulties will soon begin to present themselves, which will materially interfere with the regular and proper working of the best silver alloys; and in fact, with all qualities that have originally been prepared free from nickel. Those prepared from nickel are much more infusible than those made without it; consequently, if a piece of the nickel alloy, either by accident or design, gets intermixed with the other quality, in a subsequent melting, it will be found to float upon the surface of the molten metal for some considerable time, and thus retard the process. Alloys prepared in imitation of silver are harder and much more difficult to work than those of the true metal; therefore it can easily be imagined what alteration the latter undergo upon the addition of some of the former compounds. The hardness and toughness which these alloys possess admirably adapt them for such purposes as we have described.