This amalgam is excellently adapted for the production of impressions of various objects of nature, direct impressions of leaves, and other delicate parts of plants having been made with its aid which, in point of sharpness, are equal to the best plaster casts and have a very pleasing appearance. The amalgam has a silver-white color and a fine gloss. It is perfectly constant to atmospheric influences. This amalgam has also been used with good success for the making of small statuettes and busts, which are hollow and can be readily gilt or bronzed by electro-deposition. The production of small statues is successfully carried out by making a hollow gypsum mold of the articles to be cast and heating the mold evenly to about 140° F. A corresponding quantity of the molten amalgam is then poured in and the mold moved rapidly to and fro, so that the alloy is thrown against the sides all over. The shaking should be continued until it is certain that the amalgam has solidified. When the mold has cooled off it is taken apart and the seams removed by means of a sharp knife. If the operation is carried on correctly, a chasing of the cast mass becomes unnecessary, since the alloy fills out the finest depressions of the mold with the greatest sharpness.
II.—Bismuth, 5.5 parts; lead, 3; tin, 1.5.
III. Alloy d’Homburg.—Bismuth, {66} 3 parts; lead, 3; tin, 3. This alloy is fusible at 251° F., and is of a silvery white. It is employed for reproductions of medals.
IV. Alloy Valentine Rose.—Bismuth, 4 to 6 parts; lead, 2 parts; tin, 2 to 3 parts. This alloy fuses at 212° to 250° F.
V. Alloy Rose père.—Bismuth, 2 parts; lead, 2; tin, 2. This alloy fuses at 199° F.
The remainder are plastic alloys for reproducing cuts, medals, coins, etc.:
VI.—Bismuth, 4 parts; lead, 2 parts; tin, 1 part.
VII.—Bismuth, 3 parts; lead, 3 parts; tin, 2 parts.
VIII.—Bismuth, 4 parts; lead, 2 parts; tin, 2 parts.
IX.—Bismuth, 5 parts; lead, 2 parts; tin, 3 parts.
X.—Bismuth, 2 parts; lead, 2 parts; tin, 2 parts.
In the form of minute globules the mercury immediately separates itself from the solution and clings to the bronze object, which thereupon presents the appearance of being plated with silver. After it has been well rinsed in clean water, the amalgam may be evenly and without difficulty applied with the scratch brush.
This quick-water (in reality a solution of mercurous nitrate), is made in the simplest manner by taking 10 parts of mercury and pouring over it 11 parts of nitric acid of a specific gravity equal to 1.33; now let it stand until every part of the mercury is dissolved; then, while stirring vigorously, add 540 parts of water. This solution must be kept in closed flasks or bottles to prevent impurities, such as dust, etc., from falling into it.
The preparatory work on the object to be gilded consists mainly in cleansing it from every trace of oxidation. First, it must be well annealed by placing it in a bed of glowing coal, care being exercised that the heating be uniform. When cooled, this piece is plunged into a highly diluted sulphuric-acid bath in order to dissolve in a measure the oxide. Next it is dipped in a 36° nitric-acid bath, of a specific gravity equal to 1.33, and brushed off with a long brush; it is now dipped into nitric acid into which a little lampblack and table salt have been thrown. It is now ready for washing in clean water and drying in unsoiled sawdust. It is of the greatest importance that the surface to be gilded should appear of a pale yellow tint all over. If it be too smooth the gold will not take hold easily, and if it be too dull it will require too much gold to cover it.
| Gold | Silver | Copper | Steel | Cadmium | |
|---|---|---|---|---|---|
| I. | 2.6 | 1.0 | — | — | — |
| II. | 75.0 | 16.6 | — | — | 8.4 |
| III. | 74.6 | 11.4 | 9.7 | — | 4.3 |
| IV. | 75.0 | 12.6 | — | — | 12.5 |
| V. | 1.0 | 2.0 | — | — | — |
| VI. | 4.0 | 3.0 | 1.0 | — | — |
| VII. | 14.7 | 7.0 | 6.0 | — | — |
| VIII. | 14.7 | 9.0 | 4.0 | — | — |
| IX. | 3.0 | 1.0 | 1.0 | — | — |
| X. | 10.0 | 1.0 | 4.0 | — | — |
| XI. | 1.0 | — | 1.0 | — | — |
| XII. | 1.0 | — | 2.0 | — | — |
| XIII. | 30.0 | 3.0 | — | 2.0 | — |
| XIV. | 4.0 | — | — | 1.0 | — |
| XV. | 29.0 | 11.0 | — | — | — |
| XVI. | 1.3 | — | — | 1.0 | — |
Nos. I, II, III, and IV are green gold; No. V is pale yellow; Nos. VI, VII, and VIII bright yellow; Nos. IX and X pale red; Nos. XI and XII bright red; Nos. XIII, XIV, and XV gray; while No. XVI exhibits a bluish tint. The finished gold ware, before being put upon the market, is subjected to a special treatment, consisting either in the simple pickling or in the so-called coloring, which operation is conducted especially with alloys of low degree of fineness, the object being to give the layers a superficial layer of pure gold.
The presence of silver considerably modifies the color of gold, and the jeweler makes use of this property to obtain alloys of various shades. The following proportions are to be observed, viz.: {67}
| Color of Gold |
Gold per 1,000 |
Silver per 1,000 |
Copper per 1,000 | |
|---|---|---|---|---|
| I. | Green | 750 | 250 | — |
| II. | Dead leaves | 700 | 300 | — |
| III. | Sea green | 600 | 400 | — |
| IV. | Pink | 750 | 200 | 50 |
| V. | English yellow | 750 | 125 | 125 |
| VI. | English white | 750 | 150 | 100 |
| VII. | Whiter | 750 | 170 | 80 |
| VIII. | Less white | 750 | 190 | 60 |
| IX. | Red | 750 | — | 250 |
Other colored gold alloys are the following:
X. Blue.—Fine gold, 75; iron, 25.
XI. Dark Gray.—Fine gold, 94; iron, 6.
XII. Pale Gray.—Fine gold, 191; iron, 9.
XIII. Cassel Yellow.—Fine gold, 75; fine silver, 12 1/2; rose copper, 12 1/2.
The above figures are understood to be by weight.
The gold solders, known in France under the names of soudures au quart (13 1/2 carat), au tiers (12 carat), and au deux (9 carat), are composed of 3, 2, or 1 part of gold respectively, with 1 part of an alloy consisting of two-thirds silver and one-third copper. Gold also forms with aluminum a series of alloys of greatly varying coloration, the most curious of them, composed of 22 parts of aluminum for 88 parts of gold, possessing a pretty purple shade. But all these alloys, of a highly crystalline base, are very brittle and cannot be worked, for which reason their handsome colorings have not yet been capable of being utilized.
| ozs. | dwts. | grs. | |
|---|---|---|---|
| Fine gold | 0 | 18 | 8 |
| Fine silver | 0 | 1 | 6 |
| Fine copper | 0 | 0 | 10 |
No borax must be used in the melting of this alloy, it being of a more fusible nature than the ordinary alloy, and will not take so high a heat in enameling.
II. Red Enamel.—The enamel which forms this color being of a higher fusing point, if proper care be not taken, the gold will melt first, and the work become ruined. In the preparation of red enamel, the coloring matter is usually an oxide of gold, and this so raises the temperature at which it melts that, in order to prevent any mishap, the gold to be enameled on should be what is called a 22-carat red, that is, it should contain a preponderance of copper in the alloying mixture so as to raise the fusing point of the gold. The formula is:
| ozs. | dwts. | grs. | |
|---|---|---|---|
| Fine gold | 0 | 18 | 8 |
| Fine silver | 0 | 0 | 10 |
| Fine copper | 0 | 1 | 6 |
The following is a list of the principal classes of leaf recognized and ordinarily prepared by beaters with the proportion of alloy they contain:
| Gold grs. |
Silver grs. |
Copper grs. | ||
|---|---|---|---|---|
| I. | Red gold | 456–460 | — | 20–24 |
| II. | Pale red | 464 | — | 16 |
| III. | Extra deep | 456 | 12 | 12 |
| IV. | Deep | 444 | 24 | 12 |
| V. | Citron | 440 | 30 | 10 |
| VI. | Yellow | 408 | 72 | — |
| VII. | Pale yellow | 384 | 96 | — |
| VIII. | Lemon | 360 | 120 | — |
| IX. | Green or pale | 312 | 168 | — |
| X. | White | 240 | 240 | — |
II.—Gold, 84 parts; copper, 16 parts.
III.—Gold, 75 parts; copper, 25 parts.
I.—One hundred parts, by weight, of copper of the purest quality; 14 of zinc or tin; 6 of magnesia; 3/6 of sal ammoniac, limestone, and cream of tartar. The copper is first melted, then the magnesia, sal ammoniac, limestone, and cream of tartar in powder are added separately and gradually. The whole mass is kept stirred for a half hour, the zinc or tin being dropped in piece by piece, the {68} stirring being kept up till they melt. Finally the crucible is covered and the mass is kept in fusion 35 minutes and, the same being removed, the metal is poured into molds, and is then ready for use. The alloy thus made is said to be fine-grained, malleable, takes a high polish, and does not easily oxidize.
II.—An invention, patented in Germany, covers a metallic alloy, to take the place of gold, which, even if exposed for some time to the action of ammoniacal and acid vapors, does not oxidize or lose its gold color. It can be rolled and worked like gold and has the appearance of genuine gold without containing the slightest admixture of that metal. The alloy consists of copper and antimony in the approximate ratio of 100 to 6, and is produced by adding to molten copper, as soon as it has reached a certain degree of heat, the said percentage of antimony. When the antimony has likewise melted and entered into intimate union with the copper, some charcoal ashes, magnesium, and lime spar are added to the mass when the latter is still in the crucible.
III. Aluminum Gold.—This alloy, called Nuremberg gold, is used for making cheap gold ware, and is excellent for this purpose, as its color is exactly that of pure gold, and does not change in the air. Articles made of Nuremberg gold need no gilding, and retain their color under the hardest usage; even the fracture of this alloy shows the pure gold color. The composition is usually 90 parts of copper, 2.5 of gold, and 7.5 of aluminum.
IV.—Imitation gold, capable of being worked and drawn into wire, consists of 950 parts copper, 45 aluminum, and 2 to 5 of silver.
V.—Chrysochalk is similar in composition to Mannheim gold:
| I | II | |
|---|---|---|
| Copper | 90.5 | 58.68 |
| Zinc | 7.9 | 40.22 |
| Lead | 1.6 | 1.90 |
In color it resembles gold, but quickly loses its beauty if exposed to the air, on account of the oxidation of the copper. It can, however, be kept bright for a long time by a coating of colorless varnish, which excludes the air and prevents oxidation. Chrysochalk is used for most of the ordinary imitations of gold. Cheap watch chains and jewelry are manufactured from it, and it is widely used by the manufacturers of imitation bronze ornaments.
| I | II | |
|---|---|---|
| Copper | 83.7 | 89.8 |
| Zinc | 9.3 | 9.9 |
| Tin | 7.0 | 0.6 |
It has a fine yellow color, and was formerly much used in making buttons and pressed articles resembling gold. Later alloys, however, surpass it in color, and it has fallen somewhat into disuse. One variety of Mannheim gold, so called, contains 1.40 parts of brass (composition 3 Cu2 1 Zn) to 10 of copper and 0.1 of zinc.
| I | II | III | |
|---|---|---|---|
| Copper | 90 | 80.5 | 86.21 |
| Zinc | 10 | 14.5 | 31.52 |
| Tin | — | — | 0.48 |
| Iron | — | — | 0.24 |
A special receipt for oreïde is the following:
IV.—Melt 100 parts of copper and add, with constant stirring, 6 parts of magnesia, 3.6 of sal ammoniac, 1.8 of lime, and 9 of crude tartar. Stir again {69} thoroughly, and add 17 parts of granulated zinc, and after mixing it with the copper by vigorous stirring keep the alloy liquid for one hour. Then carefully remove the scum and pour off the alloy.
| Copper | 88.8 | 93.6 |
| Zinc | 11.2 | 6.4 |
| Or | ||
| Copper | 2.1 | 1.28 |
| Zinc | — | 0.7 |
| Brass | 1.0 | 0.7 |
| Copper | Zinc | Tin | Iron | Gold | |
|---|---|---|---|---|---|
| I. | 89.9 | 9.3 | — | — | 1.3 |
| II. | 90.8 | 8.3 | — | — | 0.9 |
| III. | 90.0 | 8.9 | — | — | 0.9 |
| IV. | 90.7 88.2 |
89.0 11.4 |
— | — | 0.5 |
| V. | 87.5 83.1 |
12.4 17.0 |
— | — | 0.3 |
| VI. | 93.5 84.5 |
6.6 15.8 |
— | — | 0.05 |
| VII. | 86.0 | 12.0 | 1.1 | 0.3 | — |
Shadke consists of copper with from 1 to 10 per cent of gold. Articles made from this alloy are laid in a pickle of blue vitriol, alum, and verdigris, until they acquire a bluish-black color.
Gui-shi-bu-ichi is an alloy of copper containing 30 to 50 per cent of silver. It possesses a peculiar gray shade.
Mokume consists of several compositions. Thus, about 30 gold foils (genuine) are welded together with shadke, copper, silver, and gui-shi-bu-ichi and pierced. The pierced holes are, after firmly hammering together the plates, filled up with the above-named pickle.
The finest Japanese brass consists of 10 parts copper and 8 parts zinc, and is called siachu. The bell metal kara kane is composed of copper 10 parts, tin 10 parts, iron 0.5 part, and zinc 1.5 parts. The copper is first fused, then the remaining metals are added in rotation.
The composition of this alloy varies considerably, but from the adjoined figures an average may be found, which will represent, approximately, the normal composition:
| Copper | 50 to 66 parts |
| Zinc | 19 to 31 parts |
| Nickel | 13 to 18 parts |
The properties of the different kinds, such as their color, ductility, fusibility, {70} etc., vary with the proportions of the single metals. For making spoons, forks, cups, candlesticks, etc., the most suitable proportions are 50 parts of copper, 25 of zinc, and 25 of nickel. This metal has a beautiful blue-white color, and does not tarnish easily.
German silver is sometimes so brittle that a spoon, if allowed to fall upon the floor, will break; this, of course, indicates faulty composition. But the following table will show how the character of the alloy changes with the varying percentage of the metals composing it:
| Copper | Zinc | Nickel | Quality | |
|---|---|---|---|---|
| I. | 8 | 3.5 | 4 | Finest quality. |
| II. | 8 | 3.5 | 6 | Beautiful, but refractory. |
| III. | 8 | 6.5 | 3 | Ordinary, readily fusible. |
| IV. | 52 | 26.0 | 22 | First quality. |
| V. | 59 | 30.0 | 11 | Second quality. |
| VI. | 63 | 31.0 | 6 | Third quality. |
The following analyses give further particulars in regard to different kinds of German silver:
| For sheet | Copper | Zinc | Nickel | Lead | Iron |
|---|---|---|---|---|---|
| (French) | 50.0 | 31.3 | 18.7 | — | — |
| (French) | 50.0 | 30.0 | 20.0 | — | — |
| (French) | 58.3 | 25.0 | 16.7 | — | — |
| Vienna | 50.0 | 25.0 | 25.0 | — | — |
| Vienna | 55.6 | 22.0 | 22.0 | — | — |
| Vienna | 60.0 | 20.0 | 20.0 | — | — |
| Berlin | 54.0 | 28.0 | 18.0 | — | — |
| Berlin | 55.5 | 29.1 | 17.5 | — | — |
| English | 63.34 | 17.01 | 19.13 | — | — |
| English | 62.40 | 22.15 | 15.05 | — | — |
| English | 62.63 | 26.05 | 10.85 | — | — |
| English | 57.40 | 25. | 13.0 | — | 3.0 |
| Chinese | 26.3 | 36.8 | 36.8 | — | — |
| Chinese | 43.8 | 40.6 | 15.6 | — | — |
| Chinese | 45.7 | 36.9 | 17.9 | — | — |
| Chinese | 40.4 | 25.4 | 31.6 | — | 2.6 |
| Castings | 48.5 | 24.3 | 24.3 | 2.9 | — |
| Castings | 54.5 | 21.8 | 21.8 | 1.9 | — |
| Castings | 58.3 | 19.4 | 19.4 | 2.9 | — |
| Castings | 57.8 | 27.1 | 14.3 | 0.8 | — |
| Castings | 57. | 20.0 | 20.0 | 3.0 | — |
In some kinds of German silver are found varying quantities of iron, manganese, tin, and very frequently lead, added for the purpose of changing the properties of the alloy or cheapening the cost of production. But all these metals have a detrimental rather than a beneficial effect upon the general character of the alloy, and especially lessen its power of resistance to the action of dilute acids, one of its most valuable properties. Lead makes it more fusible; tin acts somewhat as in bronze, making it denser and more resonant, and enabling it to take a higher polish. With iron or manganese the alloy is whiter, but it becomes at the same time more refractory and its tendency toward brittleness is increased.
There are many formulas for alloys which claim to be substitutes for German silver; but no one of them has yet become an article of general commerce. It will be sufficient to note these materials briefly, giving the composition of the most important.
| I | II | III | IV | |
|---|---|---|---|---|
| Copper | 25.0 | 45.0 | 69.0 | 47.0 |
| Nickel | 24.0 | 32.5 | 10.0 | 30.9 |
| Antimony | 50.0 | — | — | — |
| Bismuth | 1.0 | 1.0 | 1.0 | 0.1 |
| Tin | — | 16.0 | 15.0 | 1.0 |
| Zinc | — | 21.5 | 20.0 | 21.0 |
| Aluminum | — | — | 1.0 | — |
I is hard and very lustrous, suitable for lamp reflectors and axle bearings; II is hard, resonant, and not affected by sea water, for parts of ships, pipes, telegraph wires, and piano strings; III and IV are for cups, spoons, etc.
| Copper | 52 to 50 parts |
| Nickel | 17 to 15 parts |
| Zinc | 5 to 10 parts |
| Manganese | 1 to 5 parts |
| Copper, with 15 per cent phosphorus. | 3 to 5 parts |
Readily cast for objects of art.
| Iron | 66 parts |
| Nickel | 23 parts |
| Tungsten | 4 parts |
| Copper | 5 parts |
| Copper | 55.78 parts |
| Zinc | 23.198 parts |
| Nickel | 13.406 parts |
| Tin | 4.035 parts |
| Lead | 3.544 parts |
Silver white, almost ductile, suited for artistic purposes. {71}
| Copper | 70.0 parts |
| Nickel | 20.0 parts |
| Zinc | 5.5 parts |
| Cadmium | 4.5 parts |
Resembles silver; worked like German silver.
I.—Copper, 62 parts; tin, 33 parts; lead, 5 parts.
II.—Copper, 80; antimony, 11; lead, 9.
III.—Copper, 10; tin, 10; antimony, 10; lead, 40.
IV.—Copper, 30; tin, 50; silver, 2; arsenic, 1.
V.—Copper, 66; tin, 33.
VI.—Copper, 64; tin, 26.
VII.—Steel, 90; nickel, 10.
VIII.—Platinum, 60; copper, 40.
IX.—Platinum, 45; steel, 55.
X.—Platinum, 55; iron, 45.
XI.—Platinum, 15; steel, 85.
XII.—Platinum, 20; copper, 79; arsenic, 1.
XIII.—Platinum, 62; iron, 28; gold, 10.
XIV.—Gold, 48; zinc, 52.
XV.—Steel, 50; rhodium, 50.
XVI.—Platinum, 12; iridium, 88.
XVII.—Copper, 89.5; tin, 8.5; zinc, 2.
The following alloys, principally lead, are used for various purposes:
II.—Lead, 86 parts; antimony, 14 parts.
III.—Lead, 87 parts; antimony, 12 parts; copper, 1 part.
IV.—Lead, 81 parts; antimony, 14 parts; tin, 5 parts.
V.—Lead, 73 parts; antimony, 17 parts; zinc, 10 parts.
VI.—Tin, 53 parts; lead, 43 parts; antimony, 4 parts.
Hard lead is made of lead, 84 parts; antimony, 16 parts.