M. von Hauer on Fusible Alloys. 44<7 



of niobium, it was heated with magnesium. The reduction 

 takes place easily, provided the temperature at which oxide of 

 niobium is reduced is not exceeded. The magnesium and the 

 platinum boat in which the reduction took place were covered 

 with apparently regular lustrous crystals, which were not altered 

 by water, and when heated in the air were changed into hypo- 

 niobic acid. Crystals of the same kind were obtained when 

 hyponiobate of potash was heated with sodium. Probably this 

 body stands to niobium in the same relation as Peligot's uranyle 

 to uranium. 



Von Hauer has made a communication* on the easily fusible 

 alloys produced by the addition of a little cadmium to the easily 

 fusible mixture of tin, lead, and bismuth. As the alloys described 

 by Wood approached very near to mixtures in equivalent pro- 

 portions, v. Hauer fused substances together in definite pro- 

 portions and determined their fusing-point and density. The 

 specific gravity and the combining-proportion of the metals taken 

 were — 



spec. grav. 8- 5 72 equiv. 56 



Cd, 

 Sn 

 Pb 

 Bi 



The results of his 

 Table :— 



Formula. 



Cd Sn Pb Bi 



Cd Sn 2 Pb 2 Bi 2 

 Cd 3 Sn 4 Pb 4 Bi 4 



7-625 



11-350 



9-708 



58 

 103-7 

 210 



experiments are given in the following 



Specific gravity. 



Found. 



9-765 

 9-784 

 9-725 

 9-685 



Calcu- 

 lated. 

 9-624 

 9-698 

 9-666 

 9-652 



Difference. 



+ 0-141 



+ 0-086 

 + 0-059 

 + 0033 



Fusing- 

 point. 



68-5 C. 

 68-5 „ 

 67-5 „ 

 66-5 „ 



In all these cases there is a contraction, but it seems that the 

 smallest contraction accompanies the lowest melting-point. All 

 these alloys are pasty below their proper melting-points, and 

 only solidify a few degrees lower. The melting-point of an 

 alloy of 3 parts by weight of Cd, 4 Sn, 8 Pb, and 15 Bi, the 

 author found to be 70°, and not, as Lipovvitz had observed, 60°. 

 He found the melting-point of an alloy of 2 parts by weight of 

 Cd, 3 Sn, 11 Pb, and 16 of Bi to be 76°-5. 



If 8 to 10 per cent, of cadmium are added to Rose's fusible 

 metal, its melting-point sinks to 75°. If, in the same alloy, lead 



* Journal fur praJctische Chemie, vol. xciv. p. 436. Zeitschrift fur 

 Chemie, vol. i. p. 475. 



