ZOOLOGY AND BOTANV, MICROSCOPV, ETC. 119 



0. Rnff * applies the above experimental results and other recently 

 ascertained facts to the extension of the equilibrium diagram. The 

 compound FcoC exists, as well as FegC ; it dissociates rapidly at 2220^0. 

 Both carbides are endothermic compounds above 700" C. Observations 

 of the boiling points of iron and iron-carbon alloys permit the inclusion 

 of the gaseous phasi; in a portion of the diagram. The equilibrium 

 concentration of Fe^O is always less than its saturation concentration. 

 Graphite is the only solid phase which is stable in contact with the 

 liquid phase. Solidification may take place according to the stable 

 system or the metastable system. 



Iron-carbon Alloys. — H. Hanemann has determined the limit of 

 solubility of carbon in molten iron in the temperature range l;-550^- 

 1880^ C. A very pure iron-carbon alloy, completely covered with 

 carbon, was heated in a carbon crucible at the required temperature, and 

 rapidly cooled by casting in a narrow metal mould. The percentage of 

 carbon in the plate obtained was determined, and its structure investi- 

 gated. Other methods of cooling yielded specimens containing some 

 graphite. The alloy obtained by heating to 1880° C. contained 6 • 18 p.c. 

 carbon, and thus approached the composition of cementite. The micro- 

 scopical evidence indicated that when graphite was present it had 

 separated directly from the melt, and thus pointed to the existence of 

 two systems of equilibrium, the stable iron-graphite system and the 

 labile iron-cementite system. 



Iron-chromium Alloys. J — P. Monnartz has investigated 21 alloys 

 of iron and chromium, containing 3*8 to 1)8 "2 p.c. chromium and free 

 from carbon, prepared by the Goldschmidt reaction. Cooling curves 

 were taken ; a compound Gr^Fe is indicated. The resistance of the 

 various alloys to the action of acids was very fully studied. Some 

 observations on the mechanical properties of the alloys are included. 



Arndt, K. — Influence of Nature of Surface on the Rusting of Iron. 



Metallurgie, viii. (1911) pp. 353-8 (24 figs.). 



Baykoff, a. — Equilibrium Diagram of Ii-on-carbon Alloys. 



Journ. d. liuss. Md. Ges., 1910, pp. 314-55. 

 Brown, W. — Mechanical Stress and Magnetization of Nickel. 



Proc. Hoy. Dublin Sue, xii. (1910) pp. 500-18 (6 figs.) 



xiii. (1911) pp. 28-48 (6 figs.) 

 Haines, W. B. — Effect of Temperature upon the Ductility of Zinc. 



[The ductility of i-'ommercial zinc-wire was found to rise to a maximum at 

 90° (J., to fall to a minimum at 108° C, and to rise with further increase 

 of temperature to 200'^ C. The peculiarities in the neighbourhood of 

 100° C. may be due to the presence of 0'52 p.c. lead. 



Proc. Roy. Soc, Series A, Ixxxv. (1911) pp. 52G-32 (4 figs.). 



KoBAYASHi, M.— Alloys of Tellurium and Zinc. 



[The existence of the compound TeZn, melting at 1238-5° C, was demon- 

 strated by a thermal and microscopical investigation of the system.] 



Mem. Coll. Sci. and Eng. Imp. Univ. Kyoto, iii. (1911) pp. 217-21. 



* Metallurgie, viii. (1911) pp. 456-64, 497-508 (2 figs.), 

 t Stahl und Eisen, xxxi. (1911) pp. 333-6 (17 figs.). 

 X Metallurgie, viii. (1911) pp 161-76, 193-201 (9 figs.). 



