TRANSACTIONS OF SECTION ]',. 585 



S. The Reduction of some Metallic Chlorides by Calcium Carbide. 

 By Major W. E. Edwards, R.A., Captain C. H. Liveing, R.A., and 

 Professor W. R. Hodgkinson, Ph.D., F.I.C., F.R.S.E. 



Many metallic oxides are reduced to the metal when hetated with calcium 

 carbide. It is, however, an inconvenient reducing agent for oxides on account of 

 its infusibility. 



It occurred to us that it might be useful in the case of some metals, as 

 cerium, chromium, manganese, and others, the oxides of which are not easily or 

 not practically reducible by carbon in ordinary furnaces, if it would act upon the 

 chlorides or fluorides of these metals. 



The iirst experiments were made with cerium chloride simply because we 

 were trying to obtain some alloys of that metal. 



Cerium oxide is easily converted into chloride by heating with an excess of 

 ammonium chloride. On heating a mixture of this chloride with finely powdered 

 carbide there was a decided reaction in so far that calcium chloride was formed 

 and an infusible black granular substance which appeared to be a compound or 

 mixture of cerium and carbon with some unchanged carbide. 



A mixture of cerium chloride, calcium carbide, and copper in filings gave in 

 the first experiment an alloy of copper and ceriuui containing about U per cent, 

 of the latter metal. This alloy is very tough, but not appreciably harder than 

 commercial copper. 



We have since obtained alloys considerably richer in cerium, and we are 

 examining the properties of some alloys of this metal and also of didymium with 

 copper. 



Manganese chloride is equally, if not more easily, reduced by carbide, and we 

 find it a comparatively easy method of formation of manganese-copper alloys. 



Iron and nickel are not quite so convenient to employ with carbide, as much 

 carbon is taken up. 



TUESDAY, SEPI'EMIIER 16. 

 The following Papers and Reports were read : — 



1. Colloids of Zirconium, covipared ^cith those of other Metals of the 

 Fourth Grou}}. By Dr. J. H. Gladstone, F.R.S., and Walter 



HiBBERT, "F.l.C. 



On continuing the experiments on colloids, which were described in their 

 papers at Dover and Glasgow, the authors found that zirconium gave a colloid 

 of well-marked properties, resembling those of silicon, tin, titanium, and thorium. 

 The tetrachloride of zirconium is a volatile pungent body which, reacting with 

 ■water, forms hydrochloric acid, and various oxychlorides or hydroxides. The 

 gummy mass so obtained, when dried, gave beautifully regular forms of fissures 

 and spirals. The gummy solution, when heated, formed a gel which, when 

 exposed to the air, gradually lost water. Successive diff'usates from this gel gave 

 various crystalline forms on evaporation. The first dift'usate was particularly 

 rich in dagger-shaped crystals with rounded edges, which proved to be oxy- 

 chlorides. In later diff'usates this compound was gi adually replaced by crystals 

 of other forms, similar to what had been previously observed among the colloids 

 of tin and titanium, and which appeared to be free from chlorine. These crystals 

 were extremely labile, and exhibited forms always more or less curved in theiv 

 outlines. The solutions of these colloids of zirconium, tin, and titanium slowly 

 formed crusts or skins which were insoluble in water, and which slowly shrank, 

 often cracking in irregular patterns. It is a curious circumstance that the solu- 

 tion of zirconium colloid very readily produces spongy growths, similar in appear-i 

 ance to those that have previously been observed in solutions of siUcou. All 



