ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 789 



scopical results are too lengthy for reproduction. The data obtained 

 permitted the identification of some impurities in samples of zinc 

 examined. 



Bearing-metals and Stamped Alloys.* — By a process somewhat 

 resembling that described by Friedrich,f W. Guertler has made bearing- 

 metals consisting of grains of a hard metal imbedded in a plastic 

 matrix. An intimate mixture of iron and lead in fine powder was heated 

 to 250° to 300° C. and stamped in moulds. The properties of the pro- 

 duct appeared to be satisfactory. 



Copper-aluminium-manganese Alloys. J — W. Rosenhain and F. C. 

 A. H. Lantsberry have made a lengthy investigation of a number of 

 alloys belonging to this ternary system. The alloys studied fall into two 

 classes : (1) heavy alloys, containing to 11 p.c. aluminium, to 10 p.c. 

 manganese, rest copper ; (2) light alloys, containing copper and man- 

 ganese, not more than 4 p.c. of either, rest aluminium. Mechanical tests, 

 static, impact, and alternating-stress, were carried out on the alloys in 

 different states — sand-castings, chill-castings, bars, as rolled, annealed, or 

 quenched, etc. Cooling curves were taken, and the alloys were micro- 

 scopically examined. The complexity of the ternary system renders the 

 determination of its equilibrium diagram a matter of great difficulty, and 

 a complete explanation of the results obtained in the limited regions of 

 the diagram which include the alloys investigated is not attempted. The 

 constitution of the heavy ternary alloys closely resembles that of the 

 copper-aluminium alloys ; in no case does manganese give rise to the 

 formation of a third phase, so that all the alloys consist of either a single 

 solid solution (the a body) or of two phases, in each of which manganese 

 exists in a solid solution. The compound Cu 3 Al appears to be capable of 

 dissolving manganese, and there is no evidence of the formation of a 

 ternary compound. In the light alloys, three distinct phases are found : 

 (1) a solid solution, which is aluminium containing some copper but 

 practically no manganese ; (2) the compound CuAl 2 ; (3) the compound 

 Al 3 Mn. A ternary eutectic of these three phases, freezing at 522°C, is 

 probably present in most of the light alloys. No thermal changes were 

 found below the point of final solidification of the aluminium-rich alloys. 

 Corrosion tests were made on the alloys, and in some cases magnetic 

 properties were studied. 



Action of Hydrogen and Nitrogen on Temper-carbon in Iron.§ 

 It has been stated by Forquignon and by Charpy that temper-carbon in 

 iron is volatilized, as hydrocarbons when heated in hydrogen, as cyanogen 

 when heated in nitrogen. This has been disputed by Wiist and Geiger. 

 F. Wtist and E. Sudhoff have now carried out a fresh series of experi- 

 ments, samples of cast iron, containing about 1 ' 5 p.c. temper-carbon and 

 about 1 • 1 p.c. combined carbon, being heated, at temperatures 880° to 

 1080° C, in carefully purified hydrogen and nitrogen. No loss of total 

 carbon occurred in either case, but while the carbon condition was un- 



* Metallurgie, vii. (1910) pp. 264-8. f See this Journal, 1910, p. 530. 



t Proc. Inst. Mech. Eng. (1910) i. pp. 119-339 (141 figs.). (Ninth report to 

 Alloys Eesearch Committee.) 



§ Metallurgie, vii. (1910) pp. 261-4 (4 figs.). 



