| oz. | dwts. | grs. | |
| Fine silver | 0 | 15 | 0 |
| Copper | 0 | 5 | 0 |
| 1 | 0 | 0 |
Silver goods manufactured according to these standards in Germany, which have recently become law, may be alloyed only with copper, and any foreign substance is not allowed to enter into their composition. The remedy permitted in the actual fineness of the silver must not be under three thousandths of the standard specified. The goods to be stamped with the number of thousandths and the name of the manufacturer of them, and the correctness to be certified by the firm named. Experts are appointed by the Government to test this correctness, and if the provisions of the law have been justly observed a government guarantee mark is applied to them.
Silver Solders: their Uses and Applications.
[A] See observations on Depreciation of Cost Price of Silver in Preface to Fourth Edition (pp. vii, viii), and the new Table of Cost Prices of Alloys in this Chapter, following the Preface (p. x).
Soldering as applied to silversmith’s work is an art which requires great care and practice to perform it neatly and properly. It consists in uniting the various pieces of an article together at their junctions, edges, or surfaces, by fusing an alloy specially prepared for the purpose, and which is more fusible than the metal to be soldered. The solder should in every way be well suited to the particular metal to which it is to be applied, and should possess a powerful chemical affinity to it; if this be not the case, strong, clean, and invisible connections cannot be effected, whilst the progress of the work would be considerably retarded. This is partly the cause of inferior manufactures, and not, as frequently supposed, the want of skill in the workman.
The best connections are made when the metal and solder agree as nearly as possible in uniformity, that is, as regards fusibility, hardness, and malleability. Experience has proved, more especially in the case of plain and strong work (or work that has to bear a strain in the course of manufacture), that the soldering is more perfect and more tenacious as the point of fusion of the two metals approaches each other; the solder having a greater tendency to form a more perfect alloy with the metal to which it is applied than under any other conditions. The silver or other metal to be operated upon by soldering being partly of a porous nature, the greater the heat required in the fusion of the solder the more closely are the atoms of the two metals brought into direct relationship; thus greater solidity is given to the parts united, and which are then capable of forming the maximum of resistance. It is thus obvious that tin should not be employed in forming solders possessing the characteristics we have just described, for being a very fusible metal it greatly increases the fusibility of its alloys; but when very easy solder is required, and this is sometimes the case, especially when zinc has been employed in the preparation of the silver alloy, its addition is a great advantage when it comes to be applied to the work in hand. Solders made with tin are not so malleable and tenacious as those prepared without it, as it imparts a brittleness not usually to be found in those regularly employed by silversmiths; for this reason it is advisable to file it into dust, and apply it in that state to the articles in course of manufacture.
The best solders we have found to be those mixed with a little zinc. These may be laminated, rolled or filed into dust; if the latter, it should be finely done, and this is better for every purpose. Too much zinc, however, should not be added under any conditions, as it has a tendency to eat itself away during wear, thus rendering the articles partly useless either for ornamental or domestic purposes earlier than might be anticipated. Solders thus prepared also act with some disadvantage to the workman using them, for they possess the property of evaporating or eating away during the process of soldering, leaving behind scarcely anything to indicate their presence; consequently the workman has to keep on repeating the process until the connection is made perfect, which is always done at the expense of a quantity of solder as well as loss to the workman as regards time.