156 



Dr. Alder Wright and Mr. C. Thompson. [Feb. 12, 



II. " On Certain Ternary Alloys. Part III. Alloys of Bismuth, 

 Zinc, and Tin, and of Bismuth, Zinc, and Silver." By 

 R. ALDER WRIGHT, D.Sc., F.R.S., Lecturer on Chemist 

 and Physics in St. Mary's Hospital Medical School, and 

 C. THOMPSON, F.I.C., F.C.S. Received January 24, 1891. 



The general methods adopted in carrying oat the experiments 

 detailed below were identical with those described in Part II,* the 

 weighed metals being fused together under cyanide of potassium, 

 well intermixed by continued vigorous stirring, and poured into red- 

 hot narrow clay test-tubes, which were then inserted inside thin iron 

 protecting tubes, closed at the lower end, and immersed in a bath of 

 molten lead, maintained at as nearly as possible a constant tempera. 

 ture by means of a series of Bunsen flames playing into the inter 

 space between the cylindrical iron vessel containing the lead and an 

 outer concentric clay jacket. Fluctuations of temperature, to a 

 greater or lesser extent, being unavoidable during long periods of 

 heating, notwithstanding all care, some of the figures ultimately 

 deduced were less concordant than those obtained in the experime 

 previously described, the mode of separation of a given mass int 

 two different alloys being apparently more affected by temperate 

 variations with mixtures containing bismuth than with correspond- 

 ing mixtures containing lead instead of bismuth. 



Our first experiments were made with the object of determinii 

 the mutual solubilties of bismuth and zinc at different temperatni 

 Matthiessen and v. Bose found (' Roy. Soc. Proc.,' vol. 11, p. 430) tl: 

 melted bismuth could dissolve zinc, forming an alloy containing 12'93 

 to 16'30 per cent, of zinc (excluding two determinations of 8'65 

 and 8'80 per cent, respectively, presumably erroneous from some 

 undetected source of error) ; and that zinc could dissolve bismuth, 

 forming an alloy containing 2*38 to 2*48 per cent, of bismuth ; no 

 record of temperature was made in these observations further than 

 that the molten metals were ultimately poured into "a porous cell 

 which had been previously heated to redness in a large crucible fil 

 with sand." 



We obtained the following figures, approximately equal weights 

 bismuth and zinc being melted together and well stirred up, the 

 mixtures being then poured into red-hot narrow clay test-tubes, and 

 heated in the lead-bath for periods of eight hours and upwards. 



* ' Roy. Soc. Soc.,' voL 48, p. 25 ; Part I, ibid., yol. 46. x>. 461. 



