58 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



satisfactory substitute for, the method by electroplating, 

 which lias lately come so generally into use. 



The value of nickel plating is, of course, well understood, 

 and it is now very much used wherever polished iron or brass 

 is liable to corrode, as is particularly the case in the vicinity 

 of salt water. In large -yachts, where expense is no consid- 

 eration, all the metal work, as also the machinery of sea-going 

 steamers, is often treated in this way ; a notable instance of 

 which may be seen in the yacht Resolute, a splendid vessel 

 lately built for Mr. A. S. Hatch, of New York. 



The details of Professor Stolba's process are too compli- 

 cated for our pages ; but we may say, in general terms, that 

 it depends upon the action of salts of nickel in tlie presence 

 of chloride of zinc and of the metal to be coated. The sub- 

 stances required are : first, a suitable vessel for conducting 

 the operation, which may be of porcelain or metal ; second, a 

 suitable salt of nickel, which may be either chloride, sulphate, 

 or the sulphate of nickel and potassa ; third, a solution of chlo- 

 ride of zinc ; fourth, clippings of sheet zinc or zinc wire and 

 powdered zinc ; fifth, pure hydrochloric acid. Cobaltizing, 

 as Professor Stolba terms it, is conducted in very much the 

 same way a salt of cobalt being used in place of the salt 

 of nickel. 14 C, CCL, 145. 



ELECTROPLATING METAL WITH NICKEL OR COBALT. 



A process devised by Mr. ISPagel, of Hamburg, for coating 

 iron, steel, and other oxidizable metals with an electro de- 

 posit of nickel or cobalt consists in taking 400 parts, by 

 weight, of pure sulphate of the protoxide of nickel by crys- 

 tallization, and 200 parts, by weight, of pure ammonia, so as 

 to form a double salt, which is then dissolved in G000 parts 

 of distilled water, and 1200 parts of ammoniacal solution, of 

 the specific gravity of 0.909, added. The electro deposit is 

 effected by an ordinary galvanic current, using a platinum 

 positive pole, the solution being heated to about 100 Fahr- 

 enheit. The strength of the galvanic current is regulated 

 according to the number of objects to be coated. For coat- 

 ing with cobalt, 138 parts, by weight, of pure sulphate of co- 

 balt are combined with 69 parts of pure ammonia, to form a 

 double salt, which is then dissolved in 1000 parts of distilled 

 water, and 120 parts of ammoniacal solution, of the same spe- 



