120 SUMMARY OF CUBEENT RESEARCHES RELATING TO 



compound ;/■. The equilibrium diagram is accordingly shown in the 

 three dimensional system. If iron and molybdenum could be mixed at 

 1800° C. so quickly that the compound x had not time to form, two 

 series of mixed crystals only would be formed. The compound x and 

 iron do not form mixed crystals. Alloys prepared by the alumino- 

 thermic process, and thus heated to a much higher temperature, contain 

 distinctly more of the compound x. The structure of alloys prepared in 

 either way is not altered by heating to 1200° C. and quenching, showing 

 that the differences are not due to reactions occurring in the solid state. 

 It appears that the amount of the compound present slowly increases as 

 the temperature rises. A similar case is that of aluminium and antimony. 



Copper-bismuth Alloys. — K. Jeriomin* gives the equilibrium 

 diagram, differing considerably from Gautier's. No compound is formed. 

 If mixed crystals exist, their concentration is very low — less than ■ 5 p.c. 

 copper in bismuth, or bismuth in copper. The eutectic contains not 

 more than 0*5 p.c. copper. 



A. Portevin f has also determined the equilibrium diagram, and states 

 that neither compounds nor solid solutions are formed. The eutectic 

 contains very little copper. Crystals of copper are found in the alloy 

 with • 3 p.c. copper. 



Zinc-cadmium Alloys.^ — G. Hindrichs gives the equilibrium 

 diagram, showing no compounds or solid solutions. The eutectic com- 

 position and temperature are £2*6 p.c. cadmium and 270° C. The 

 thermal results were confirmed by microscopic examination. 



Antimony-lead Alloys. § — W. Gontermann has re-determined the 

 equilibrium diagram, because of some discrepancies and omissions in 

 previous determinations. No compounds or mixed crystals are formed. 

 A peculiarity was noted in the cooling curves of the alloys from which 

 antimony first crystallises. The eutectic point is apparently double, 

 two halts occurring at temperatures about 5° C. apart. After showing 

 that this cannot be due to the formation of a compound or to changes 

 occurring in the solid state, the author suggests the explanation that 

 the double halt is due to the difference in solubility of large and small 

 crystals of antimony. 



Special Cast Irons. || — By adding nickel in increasing amounts to 

 (1) white iron, (2) grey iron, L. Guillet prepared a series of nickel cast 

 irons. Microscopic examination showed that nickel favours the forma- 

 tion of graphite. Similar tests were made with manganese. The author 

 arrives at the general conclusion that those elements which enter into 

 solution in iron (nickel, aluminium, silicon) . promote the formation of 

 graphite, while the elements which form a double carbide with cementite 

 (manganese, chromium) tend to prevent graphite formation. 



* Zeitschr. Anorg. Chexn., lv. (1907) pp. 412-14 (1 fig.). 

 t Rev. de Metallurgie, iv. (1907) pp. 1077-80 (4 figs.). 

 % Zeitschr. Anorg. Chern, lv. (1907) pp. 415-18 (1 fig). 

 § Tom. cit., pp. 419-25 (2 figs.). 

 || Comptes Kendus, cxlv. (1907) pp. 552-3. 



