108 THE CANADIAN NATURALIST. [March 



a glass tube with twenty times its weight of pure oxyd of lead, and 

 then heated before the blow-pipe until complete fusion and the disap- 

 pearance of all froth. The loss in weight corresponds to the car- 

 bonic acid formed from the graphite, with the oxygen of the lith- 

 arge. The pulverized graphite, may also be fused with pure 

 nitrate of potash in a platinum crucible, and the carbonate formed 

 determined in the usual manner. — {Glutl. Acad, of Vienna.) 



T. S. H. 



On Phosphorus in Iron. — The importance of manganese as 

 an element in iron ores has long been known, and the experiments of 

 Caron have shown that the addition of manganesian minerals to the 

 charge of the blast furnace has, for eflPect, to reduce notably the 

 amounts of sulphur and of silicon which pass into the pig metal. 

 At the same time, however, it does not, in any way, diminish 

 the proportion of phosphorus. This element generally exists 

 in the ores as a phosphate of Hme, or in combination with alumina 

 or oxyd of iron. These latter are generally decomposed by the 

 addition of lime, which in its turn requires silica to give a liquid 

 slag. The reaction of silica and carbon, at "a heat of fusion, on 

 phosphate of lime, sets free the phosphorus, which unites directly 

 with the metallic iron ; so that, while the slag is free from phospho- 

 rus, the pig metal contains it in quantities often so large as to be 

 very prejudicial. 



A solution of the problem of the treatment of phosphuretted 

 ores would seem to require some flux capable of dissolving or ren- 

 dering fusible the phosphate of lime without liberating its phos- 

 phorus. Such a power is possessed by fluor-spar ; and the experi- 

 ments of Caron show that while a mixture of phosphate of iron, 

 lime and siUca, fused in a charcoal-lined crucible, gave a button of 

 brittle metal highly charged with phosphorus, a mixture of phos- 

 phate of iron, lime and fluor-spar, fused under similar conditions, 

 was somewhat malleable, and contained only one -third as much 

 phosphorus as the first assay. In operating in this way on natural 

 and less phosphated ores, it was found that the substitution of 

 fluor-spar for silica always produced a notable diminution in the 

 amount of phosphorus in the metal ; but the improvement became 

 less marked with ores holding small amount of phosphorus. Fluor- 

 spar has also the eff'ect of dissolving alumina in the furnace. 



It is questionable how far this process could be applied in the 

 metallurgy of iron, inasmuch as few ores are free from silica. 



