526 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Up to about ] p.c. carbon a solid solution only is formed ; microscopic 

 examination indicates that the limit of solid solubility lies at about 

 0*9 p.c. carbon. When more carbon is present a eutectic containing 

 between 2 and 2 "5 p.c. carbon, and melting at 1307° to 1318 0., is 

 formed. Alloys containing 2 to 2 • 5 p.c. carbon appear to consist, 

 microscopically, wholly of eutectic, while a suggestion of primary crystals 

 of the carbon-bearing phase may be observed in the alloy with 2 ■ (! p.c. 

 carbon. No difference in micro-constitution between alloys slowly 

 cooled and those water-quenched from the molten state could be detected. 



Lead Bronzes.* — F. Giolitti and M. Marantonio have studied the 

 ternary system copper-tin-lead, in the range to 20 p.c. lead, to 

 25 p.c. tin. No compounds are formed in the binary system copper- 

 lead, the components are incompletely miscible in the liquid, and im- 

 miscible in the solid state, and the eutectic temperature is practically 

 the melting-point of lead. In the ternary alloys the tin exists either as 

 Cu 4 Sn or Cu 3 Sn. The hardness of the alloys was investigated. 



Magnetic Properties of Manganese, Vanadium, and Chromium.t 

 P. Weiss and K. Onnes have found that at the freezing point of hydrogen 

 (14° absolute) the magnetic properties of manganese, vanadium, and 

 chromium are still very feeble. These metals therefore neither become 

 ferro-magnetic nor obey Curie's law of paramagnetism. The magnetic 

 properties of a crystal of ferrous sulphate became enormously stronger 

 at low temperatures. Ferro-magnetic manganese was obtained when 

 very pure reduced manganese in the form of powder was melted in a 

 current of hydrogen. 



Magnetic Properties of Iron and Alloys.j — 0. F. Burgess and 

 J. Aston have determined the magnetic and electrical properties of seven 

 iron-silicon alloys, prepared from electrolytic iron, and containing 0'23 

 to 4* 65 p.c. silicon, as forged, annealed at 075° C, annealed at 1000° C, 

 and quenched from 900° 0. The addition of silicon does not appear to 

 bring about the same improvement in magnetic properties in electrolytic 

 iron as in commercial mild steels. Electrical resistance increases with 

 increase of silicon content ; the resistance of the 4 '65 p.c. Si alloy is five 

 times that of electrolytic iron. 



The same authors § have made similar tests on electrolytic and other 

 samples of iron, of varying degrees of purity, and also on a number of 

 samples of commercial iron and steel. 



Phosphides of Iron. || — N. Konstantinow has taken cooling curves 

 of thirty alloys, containing 0*5 to 21 '0 p.c. phosphorus, and gives an 

 equilibrium diagram, differing in some respects from Saklatwalla's, based 

 on the thermal results and on the microstructure of the alloys. Some of 



* Gaz. Chim. Ital., xl. (1910) pp. 51-77, through Journ. Chem. Soc, xcviii. 

 {1910) pp. 504-5. f Comptes Rendus, cl. (1910) pp. 687-9 (1 fig.). 



X Met. and Chem. Engineering, viii. (1910) pp. 131-3 (6 figs.). 

 § Tom. cit., pp. 191-4 (G figs.). 

 || Zeitschr. Anorg. Chem., lxvi. (1910) pp. 209-28 (10 figs.). 



