TECHNOLOGY. 599 



about 10 per cent, of nickel. It is completely free from all 

 traces of sulphur, arsenic, iron, and copper; and if cobalt is 

 found with it, it is in very minute quantities. Over 20,000 

 tons of this ore, it is said, have been shipped to France and 

 England from New Caledonia ; and the production of nickel 

 therefrom, on account of its freedom from the above-named 

 troublesome elements, and from the lead, bismuth, and anti- 

 mony which are found in the German nickel ores, is effected 

 with comparatively little difficulty and cheaply. The price 

 of nickel, in consequence, has fallen to three or four shillings, 

 from the twelve to sixteen shillings which was the old mar- 

 ket figure for nickel. These new ores appear, therefore, to 

 have done for nickel what the Australian tin deposits have 

 done for the last-named metal, at least for the time, in reduc- 

 ing its price to considerably less than one half its long-estab- 

 lished value. Considering the wide range of uses to which 

 nickel is applied, and for which it is known to be adapted, 

 the discovery of new sources which appear to promise a sup- 

 ply large enough to permanently reduce its price, and to pro- 

 portionately extend its applications in the useful arts, is a 

 subject for congratulation. Professor Silliman, however, is 

 careful to add that " we are by no means sure, as yet, that 

 the Caledonian deposits are as permanent as the hopeful own- 

 ers have represented." The same gentleman notices from 

 the Exhibition that very decided advances have been made 

 in England in working the platinum metals. He notices like- 

 wise the production by an English house of an excellent alloy 

 for subsidiary coin, consisting of aluminum ninety-eight and 

 nickel two parts. It is silver-white, hard as silver, unoxidiz- 

 able, and extremely light. 



PLATING METALS BY GALVANIC MEANS. 



A process for platinum -plating has been devised by 

 Boettger, which is claimed to yield a coating of fine color, 

 great tenacity, and durability, qualities in which all previous 

 processes were deficient. The improvement referred to de- 

 pends upon the fact.Avhich Boettger has observed, that the 

 neutral citrate of soda will dissolve very readily large quan- 

 tities of the platin-ammonium chloride, which is the plating 

 solution commonly used, and with which the difficulty has 

 been met that, owing to its difficult solubility in water, only a 



