M. TECHNOLOGY. 537 



tion and non-abrasion of the journals, with the firm resist- 

 ance to pressure and stability of form of bearings of hard 

 metals. The test of practice alone can decide the value of 

 these claims, though they seem very plausible. 3 A, October 

 24, 1874. 



A NEW SILVER-LIKE ALLOY. 



A new and inoxidizable alloy, resembling silver, has lately 

 been patented by Le Marquand, of Paris, and has the follow- 

 ing composition per kilogramme : 



Pure Copper 750 grammes. 



Nickel *. .. 140 " 



Black oxide of Cobalt 20 " 



Tin in drops 18 " 



Zinc 72 " 



These different ingredients are to be melted together in a 

 crucible. 9 B, May 6, 208. 



PLATING WITH ALUMINIUM. 



The following process for covering metal surfaces with 

 aluminium is recommended by J. A. Jeancou : Dissolve any 

 desired quantity of a salt of aluminium, such as sulphate, 

 chloride, nitrate, cyanide, etc., in distilled water, and concen- 

 trate the solution to 20 Beaume (at 50 Fahr.) in a vessel 

 suitable for holding the article to be plated. The battery 

 to be used should either be four pairs of Smee's or three of 

 Bunsen's, with the elements connected for intensity, and a 

 plate of aluminium attached to the positive pole. The solu- 

 tion should be slightly acidulated with its appropriate acid, 

 heated to 140 Fahr., and kept at that temperature during 

 the operation. 



MANUFACTURE OF STEARIC ACID. 



In order to facilitate the removal of the oleic acid in the 

 manufacture of stearic acid, Deisz suggests the addition of 

 20 per cent, of bisulphide of carbon to the mass before press- 

 ing, since but one pressing in the cold will then be required 

 to remove the oleic acid thus diluted, and the bisulphide can 

 easily be removed by distillation. The process is, however, 

 considered objectionable by Professor Heeren, on account of 

 the unavoidable loss of bisulphide, as well as the injurious 



Z 2 



