Dissolving fine silver.—Nitric acid, two parts; water, one part.Dissolving silver alloys.—Nitric acid, one part; water, two parts.Dissolving copper.—Nitric acid, one part; water, four parts.Dissolving soft solder.—Perchloride of iron, one part; water, four parts.Dissolving silver solder.—Nitric acid one part; water four parts.Dissolving sealing-wax.—Place for a time in a solution of spirits of wine.
Dissolving fine silver.—Nitric acid, two parts; water, one part.
Dissolving silver alloys.—Nitric acid, one part; water, two parts.
Dissolving copper.—Nitric acid, one part; water, four parts.
Dissolving soft solder.—Perchloride of iron, one part; water, four parts.
Dissolving silver solder.—Nitric acid one part; water four parts.
Dissolving sealing-wax.—Place for a time in a solution of spirits of wine.
Resist Varnish.
Dissolve resin, or copal, in essence of turpentine, or boiled linseed oil; to give it different shades of colour, add red lead, chrome yellow, or Prussian blue.
Plate Powder.
Whitening, two parts, white oxide of tin, one part, calcined hartshorn, one part. Reduce to a powder and well mix together; apply as usual.
Electro-plating Soft Solder.
Take nitric acid, 1 oz.; water, 2 oz.; copper about 1 oz. in small flat pieces; when the copperhas all dissolved and effervescence has ceased, the solution is ready for use. To apply it, take up a few drops by means of a camel-hair pencil and apply it to the desired part, then touch it with a bright piece of steel, and there will be instantaneously a film of copper deposited. If the copper has not spread all over the desired part, the process should be repeated, when deposition in the plating bath will take place with perfect success.
Another Recipe.
Take sulphate of copper (that which accumulates in the whitening mixture), one ounce; water, six ounces. Reduce the sulphate of copper to a fine powder and dissolve it in the water. Treat according to the directions given in the previous one. A good mixture for effecting the same result may be made by dissolving verdigris in vinegar.
Testing Silver Wares.
Take nitric acid, six ounces; water, two ounces; bichromate of potash, one ounce. Reduce the salt of potash to a powder and well mix it with the acid and water. The solution is used cold, and should be placed in a stoppered glass bottle, the stopper having a long dropper extending into the mixture, which acts as the agent for conveying the liquid from the bottle to the article to be tested. Thesurface of the article should be perfectly clean, and to make certain what kind of metallic substance you are testing, it is advisable to rub a file over some obscure part of the surface and to apply the liquid to that part. The test liquid should be used, by means of the glass stopper, to the filed part, and immediately removed by a sponge damped with cold water. If the article consists of pure silver, there will appear a clean blood-red mark, which is less deep and lively in proportion to the quality of the metal. Upon platinum the test liquid has no action whatever; on German silver at first a brown mark appears, but this is removed by the sponge and cold water; on Britannia metal a black mark is produced; and on all the various metals an entirely different result takes place to that on silver; therefore the test is a simple one, and may be advantageously employed for the detection of any fraud in relation to the precious metal.
Another Test.
Water, 2 oz.; sulphuric acid, 2 drs.; chromate of potash, 4 dwts. This mixture is applied in the same way as before and produces a purple colour of various depths, according to the quality of the silver. No other metallic element exhibits the same colour with this preparation.
Perchloride of Iron.
Take spirits of salts, 8 oz.; crocus powder (jeweller’s polishing material), 1 oz.; well mix them together and keep in solution. In preparing the mixture for the dissolution of soft solder, &c., take 1 oz. of it, and add to it 4 ozs. of boiling water.
Aluminium Alloy.
Copper, 18 dwts; aluminium, 2 dwts.
New Alloy.
Zinc, 19 dwts; soft iron, 1 dwt. This alloy is said by the inventor to be remarkable for its whiteness and tenacity.
Removing Gold from Silver Wares.
Sometimes the process of annealing and boiling-out fails to effect the removal of the gold from articles which have been thickly gilt, in which case the work should be submitted to the action of the following chemical preparation:—Sulphuric acid, 6 ozs.; muriatic acid, 1 oz.; nitric acid, ½ oz. This mixture should be heated in a black-lead crucible or earthen vessel, and the work immersed until the dissolution of the gold takes place, carefully watching it during the progress of the operation. The gold may also be removed by using a strong solutionof oil of vitriol, to which has been added a fair proportion of common salt.
Silver Plating Fluid.
Nitrate of silver, 1 oz.; cyanide of potassium, 2 ozs.; water, 12 ozs. Put the cyanide and the nitrate of silver into the water; shake them well together until they become thoroughly dissolved, then let the mixture stand till it becomes thoroughly clear. It is then ready for use. If preferred, a little prepared chalk may be used as an additional ingredient.
Plate-cleaning Powder.
Take of the finest rouge, and prepared chalk, equal parts, well mix and use dry by means of soft leather.
Solder for Aluminium.
Spelter, 18 dwts.; aluminium, 1 dwt. 6 grs.; copper, 18 grs. To be employed for soldering thepurewhite metal, and not the so-called aluminum bronze, that being commonly soldered with bath-metal solder.
CHAPTER XV.
Foreign Silver Standards—Pre-War.
Table showing the various standards of the silver work manufactured in the principal countries previous to the European War, 1914-1918:—
In France, all articles manufactured as silver are subject toGovernment controland pay duty, but this is very slight compared with the English duty, amounting only to onefrancperhectogramme, which is equal to about threepence per ounce. This is exclusive of the charge for testing and marking; the state of the articles sent for this purpose with regard to the state of manufacture is, moreover, very different from the custom in this country. Here they are sent in their rough or half-manufactured state, and this seems better suited to the particular processes through which they have to pass; whereas in France they may be tested and marked in their whole or finished state; and, if thought requisite, this operation may be performed while the goods are on their way to their final destination, by calling at the Control Office for that purpose.
The Continental silversmiths, especially the French workmen, exhibit much ingenuity, original thought, and refined taste, in the execution of their work; and the natural capacity for design which they possess enables them to produce articles of a very high order and artistic character. The construction of some of their productions is exceedingly ornamental and decorative, and in some instances this is even carried to excess, as may be seen from some very elaborate articles which they manufacture.
To them belongs the credit of being producers of the most artistic and best decorative work in the whole world. They set thefashionsand work them out with a will to be only found in a people so enthusiastic as the French. Their jewellery is very elegant, light, and showy; some of which is prepared so thin as regards material, that it has to be supported underneath by a wax composition, which, however, gives increased strength to all articles so manipulated. With regard to articles ofvertu, the French workmen certainly far excel those of any other country: they are more original, and bring into play greater ingenuity in the various processes which they employ in their manufactures. Still with all this ingenuity and skill, their works of art in this department are notdurable, being verytinselfied; in wear their shape and form soon undergo a change, and eventually they soon get destroyed. In this branch of art the French workman might learn something to his advantage from the English style of work, which is the most durable of any nation in the world. French silver plate and jewellery of the best manufacture partake of the first standard; all other kinds are of the lowest standard.
In Germany all silver manufactures are placed underImperativecontrol, and lower standards than those given in the table, under their respective heads, cannot be worked. The German style is similar to that of the French, but the former manufacture an unusually large quantity of filigree articles, very light in construction, tasteful, and cheap; and the possession of these advantages enables them to export to England and other countries their wares at a cheap rate. They are commonly sold by weight, and not so much per article; in many cases the charge does not exceed 12s.6d.per ounce. In filigree work the Germans cannot equal the taste and variety displayed in Indian workmanship. In India the natives have definite designs, but the Germans are too fond of a variety of colours in their wares, which do not always harmonize with their particular kind of work.
In Austria silver manufactures are commonly ornamented by enamel, niello, &c., which gives them a very pleasing appearance. They are usually light and showy, and something after the style of French work. The laws affecting the Austrian silver workers are the same as those of Germany.
The English style of work is strong and solid; and is undoubtedly superior to that of all Continental manufacturers as regards substantial workmanship, careful manipulation, and durability. It is, moreover, capable of a higher finish, and possesses more evenness of surface, together with a combination of strength, that admirably suits it for articles and utensils for daily use, and which causes it to be preferred before that of any other nation; and while France, Germany, and other countries may exhibit greater ingenuity, to England belongs the credit of producing the bestfinishedand the mostdurablework of any nation in the world.
INDEX.