HO SUMMARY OF CURRENT RESEARCHES RELATING TO 



peated, using a-brass (70-30) in zinc, instead of copper in zinc. 

 After fifty-sis hours' annealing, at a temperature not exceeding 450° C, 

 a layer of/j was found to have been formed between and sharply divided 

 From the a and y. Further repetitions of the experiment, using anneal- 

 ing temperatures from 400 C upwards, gave a layer of (3 in every case. 

 The failure to obtain any evidence of the breaking down of ft 

 into a and y, and the clear proofs that stable (3 (or /3j) may be formed 

 from Clipper and zinc or from other phases, at temperatures well below 

 the critical point at 460° C, demonstrate that the 460 0. change is not 

 a eutectoid point, but is a polymorphic change occurring in the /3-phase, 

 and that /3 1 is a stable phase below 460° C. 



Bismuth-cadmium Alloys.* — G. J. Petrenko and A. S. Fedorow 

 find that bismuth and cadmium form a simple entectiferous series of 

 alloys, the solid solubility of bismuth in cadmium, and of cadmium in 

 bismuth, being very slight, probably less than - 1 p.c. The microscopic 

 examination of the alloys at each end of the series may give misleading 

 results, owing to the effects of segregation. The eutectic segregates to 

 the upper part of the ingot in the bismuth-rich alloys, and to the lower 

 part in the cadmium-rich alloys ; in each case regions free from eutectic 

 may be found, consisting of homogeneous crystals, which may be mis- 

 taken for homogeneous solid solutions. 



Bismuth-arsenic Alloys.t — W. Heike describes the microstructure 

 of alloys containing 5 to SO p.c. arsenic. Bismuth and arsenic are 

 mutually miscible in the liquid state. Arsenic separates primarily on 

 cooling, and approximately pure bismuth crystallizes last. The sections 

 were etched with dilute copper-ammonium-chloride solution, which 

 coloured the bismuth a reddish brown, the arsenic remaining bright. 



Manganese-carbon, Nickel-carbon, Iron-carbon, and Cobalt-carbon 

 Systems. £— O. Ruff, W. Bormann, and P. Keilig have studied the 

 equilibrium diagrams of these binary systems at temperatures up to 

 2700° C , and incidentally describe the structure of some of the alloys 

 obtained. The cobalt-carbon alloys, containing up to 11 '5 p.c. carbon, 

 showed graphite lamella} embedded in cobalt. The cobalt-carbide, stable 

 at high temperatures, decomposed into cobalt and graphite on cooling. 



Malleable Castings. § - W. H. Hatfield discusses the modifications 

 in structure brought about by the annealing process in the manufacture 

 of malleable cast iron, and describes the microstructure of foundry cast 

 iron, Swedish white iron, and malleable cast iron made by the Reamur 

 and by the black-heart processes. 



Reduced Metals in Crystallized Form.|| — J. II. Bowman describes 

 a method of reducing metals in crystallized form on gla«s slips as per- 



* Int. Zeitschr. Metallog., vi. (1914) pp. 212-16 (1 fig.). 



t Int. Zeitschr. Metallog., vi. (1914) pp. 209-11 (3 figs.). 



X Zeitschr. Anorg. Ghern., lxxxviii. (1914) pp. 365-423 (13 figs.). 



§ Foundry Trade Journal, xvii. (1915) pp. 248-52 (7 figs.). 



|| Journ. Amer. Chem. Soc, xxxvii. (1915) pp. 1468-71 (6 figs.). 



