ELECTRO-METALLURGY 221 



pound to the gallon of hot water ; five gallons is to be applied to the porous cell which 

 contains the amalgamated zinc pole, three inches broad, seven inches deep, and seven 

 inches long ; but touching within one-half of an inch all around from the cell. The 

 copper-wire is connected to hold suspended the articles, such as faucets, pistols, or 

 other ware to be plated with nickel ; the operation goes on at once and deposits the 

 metallic nickel from its solutions in the space of three or four hours." It must be ac- 

 knowledged that the details here given are not of the clearest kind, and some portions 

 of the apparatus appear to have been forgotten. Mr. Beardslee, whom Dr. Feucht- 

 wanger says is the veteran nickel-plater of the States, gave the latter valuable infor- 

 mation. Mr. Beardslee finds the best results to be given by the chloride of nickel 

 and a certain quantity of ammonia. He uses the chromium negative plate battery in 

 two cells. The amount of battery-power required for a given amount of work should 

 be in zinc surface equal to the surfaces to be coated at one time. The surface of a 

 nickel anode should never be less than the surface to be coated. " The anode surface 

 for a nickel solution may be much greater than the surface to be coated ; and more 

 and better work will be the result." A nickel solution of 40 gallons requires 10 

 anodes of 6 x 12 in. and so in proportion to the greater or less quantity of gallons. 

 The nickel anodes are connected to the chromium or carbon plates of the battery (Mr. 

 Beardslee prefers chromium) ; the articles to be coated with the zincs. In the small 

 way Mr. Beardslee employs in one gallon of the nickel solution a nickel anode of 

 4x6 in., with two one-gallon cells of the chromium negative plate battery ; and he 

 states that the chloride solution works better when it exhibits an acid reaction. 

 Possibly, however, Stolba's method is the simplest of all, and is easily applicable. To 

 some chloride of zinc add double the quantity of water, boil and add hydrochloric acid 

 slowly till the precipitate is re-dissolved. A very little zinc powder is added, and in 

 a few minutes the vessel is coated with zinc wherever the liquid touches it. The 

 nickel salt (either the chloride or sulphate) is then added in sufficient quantity to turn 

 the liquid of a greenish tint. The articles are then introduced with some cuttings of 

 zinc; the whole being boiled for about 15 minutes, when the coating will be found 

 complete. It is scarcely necessary to say that whatever process is employed, the 

 surfaces to be coated must be perfectly clean, which is best secured by dipping in acid ; 

 and when they are plated they must be washed with hot water and polished with 

 cloth buffs and crocus, rouge, or other polishing powder. By means of the thin 

 coating of nickel, articles of iron and steel are prevented from rusting, while those of 

 brass, copper, lead, or zinc, are preserved from tarnish ; nickel-plating, too, has the 

 advantage over silver-plating that it lasts four times as long and costs about one- 

 fourth, while it is less liable to lose its polish.' 



Electro-deposition of nickel has been effected from several of the salts of nickel in 

 solution ; but, until recently, the process has not been worked commercially. The 

 Plating Company working Brookes' patent have been eminently successful by the 

 following processes : which we copy from their Specification of Patents : 



* The solutions from which nickel has been heretofore most successfully deposited 

 are the chloride of nickel, the cyanide of nickel and potassium, the double sulphate of 

 nickel and ammonia, and the double chloride of nickel and ammonium. The inventor 

 of the recently-patented process believes the chloride is the best, but the deposits 

 obtained from it are very far from what is required for the general purposes to which 

 the electro-deposition of this metal may be applied. As this solution is ordinarily 

 prepared, it is a good conductor of electricity as compared with most liquids, and the 

 nickel is deposited from it freely, but in a spongy, brittle condition, and more or less 

 mixed with the peroxide of nickel, which gives it a brownish appearance. The deposit 

 has also a great tendency to accumulate on the edges of the plate on which it is made 

 in nodules or warty protuberances. Therefore, although the deposits maybe obtained 

 of considerable thickness, they are practically useless for electrotyping or electro-plating. 

 Moreover, a portion of the electricity is expended in forming a sub-chloride of nickel, 

 which falls to the bottom of the vessel as an insoluble precipitate. In consequence of 

 this, the solution is soon exhausted, both of nickel and chlorine, and the process of 

 deposition stops. Even when the solution is formed in the best-known manner, by 

 subliming a pure nickel-chloride, the deposited metal, though free from the oxide, and 

 therefore white, is deposited in the brittle, warty condition, accompanied with the 

 precipitation of sub-chloride. The double cyanide of nickel and potassium is a poor 

 conductor of electricity, and requires high battery-power. With a low battery-power 

 very little metal can be deposited, and that little is accompanied with the deposition 

 of peroxide of nickel to such an extent as to be black or nearly black. With a high 

 battery-power a film of white nickel may be obtained, but not thick enough to satisfy 

 the ordinary requirements of electro-plating. 



' Neither of these solutions gives for any great length of time the full equivalent of 

 metal for the electricity employed ; and, so far as the patentee has been able to 



