122 Chronicles of Science. [Jan., 



Metallurgy. 



At the meeting of the Academie des Sciences of Paris, on the 7th 

 November, M. Pelouze, in the name of M. Leguer, presented a note 

 relative to the effects of Wolfram upon Charcoal Iron. It would 

 appear from this note that the addition of but a very small quantity 

 of either wolfram or tungsten increased the tenacity of the iron, and 

 its resistance to fracture. 



M. Margueritte, who has devoted considerable attention to the 

 manufacture of steel by cementation, has combated the views of 

 M. Caron, who inclines to the idea that combinations of carbon with 

 nitrogen (cyanides) were necessary to the production of steel ; 

 that, in fact, steel could not be made unless nitrogen, in some state of 

 combination, was present. His words are — "Toutes les fois qu'on 

 cemente le fer industriellement on le met constamment en contact 

 avec du cyanhydrate d'ammoniaque gazeux ou des cyanures volatils. 

 Dans la pratique les cyanures seuls cementent." This view has been 

 entertained by several English metallurgists. The results of a very 

 extensive series of experiments, under almost all the desired condi- 

 tions, are thus expressed by M. Margueritte : — " I maintain, then, my 

 conclusions, which are absolutely contrary to those of Mr. Saunderson 

 and M. Caron. Mr. Saunderson has pretended that pure carbon will 

 not convert iron into steel ; and M. Caron has said — ' Cyanures 

 (cyanides) are the only agents of cementation.' I believe I have 

 proved that pure carbon (the diamond), and also the oxide of carbon, 

 can transform iron into steel ; and that they should be counted 

 amongst the most active and abundant elements in the processes of 

 cementation. "J To this M. Caron has replied by enumerating some 

 new experiments, which lead him to the conclusion, that " Ces agents 

 de carburation sont insignifiants dans la pratique, et s'ils meritent 

 d'etre comptes c'est parmi les moins actifs et les moins utiles de la 

 cementation industrielle." * So the discussion rests at present, 

 although M. Margueritte replied to M. Caron at a more recent meet- 

 ing of the Academy. 



A patent has been secured for a new process, by which the sur- 

 faces of iron castings may be hardened. When a piece is filed up, or 

 finished, it is brought to a cherry-red heat, and then immersed till 

 quite cold in a solution composed of 1*080 grammes (of 15£ grains 

 each) of sulphuric acid, and 65 grammes of nitric acid to 10 litres 

 (about nine quarts) of water. The patentee informs us that the iron 

 suffers no distortion, and that the stratum hardened is sufficient for 

 all ordinary purposes. 



In a previous page we have noticed Dr. Crace Calvert's process of 

 treating gold ores. Mr. Beelback, of Newark, U.S., has patented an 

 improved process for separating silver and gold, from lead. He melts 

 the lead containing these metals in a furnace with an inclined hearth, 

 then draws it off into a kettle in which is a proper quantity of zinc to 

 take up the silver and gold. After being well stirred together, this 

 mixture is run into pigs or masses of a suitable size for re-melting. 

 * ' L'Institiit,' No. 1603. f ' L'Institut,' No. 1606. 



