254 SUMMARY OF CURRENT RESEARCHES RELATING TO 



ternary solid solutions, binary solid solutions of CugSn or CugP in copper, 

 the compound CugP, and the eutectic of CugP and a solid solution. 



Aluminium Brasses.* — M. Levi-Malvano and M, Marantonio have 

 studied a number of alloys containing 58-70 p.c. copper, 1-4 p.c. 

 aluminium, the remainder being zinc, by thermal and microscopical 

 methods. The alio , s lie within the ternary system Cu-Zn-CugAl. In 

 the binary system CugAl-Zn the liquidus curve falls from the melting- 

 point of CugAl, 1020° C, to that of zinc, and consists of four branches ; 

 the solid phases are all solid solutions. The ternary system Cu-Zn-CugAl 

 contains a number of solid solutions. 



Silver-zinc-lead System. f — R. Kremann and F. Hofmeierhave made 

 a thermal and microscopical investigation of this ternary system. Onlv 

 one of the binary systems contains compounds. These compounds, 

 Ag2Zn:,, AggZug, AgZn, and AggZug, together with the three pure metals, 

 may be regarded as components of the five ternary systems into which 

 the complete system may be divided. The system Pb-Zn-Ag^Zn^ was 

 more fully studied, since it lias a practical application in Parkes' de- 

 silverizing process, in which the crystals separating on cooMng are solid 

 solutions of AggZn^ and zinc. The ternary eutectic contains about 

 97 "5 p.c. lead and melts at 305° C. Measurements of the E.M.F. given 

 by the alloys against zinc in a solution of zinc-sulphate, show that lead 

 does not form solid solutions with zinc and silver. 



Zinc-lead-tin System. |—M. Levi-Malvano and 0. Ceccarelli have 

 examined, thermally and microscopically, more than ninety alloys, and 

 give an equilibrium diagram of the ternary system. There are two 

 liquid phases of limited miscibility. The ternary eutectic contains 

 71 p.c. tin, 24 p.c. lead, 5 p.c. zinc, and melts at 177° C. Needle shaped 

 zinc crystals can be easily detected microscopically even when present in 

 small quantity. The hardness of the alloys was measured. 



Formation of Metallic Solid Solutions by Diffusion in the Solid 

 State. §—G. Bruni and D. Meneghini have obtained binary solid solu- 

 tions by heating by means of an electric current, wires consisting of one 

 pure metal coated electrolytically with another metal. In each case the 

 highest temperature reached was below the melting point of either metal. 

 The pairs of metals were nickel-copper, gold-copper and gold-silver. 

 The formation of the solid solution was indicated by the great increase 

 in electrical resistance. 



Porosity of Iron.||— J. A. N. Friend concludes that the surface of 

 iron is slightly porous, from experiments carried out upon Kahlbaum's 

 pure iron foil. Cleaned pieces were immersed in sodium hydrate 

 solution, were then thoroughly washed, and allowed to stand in distilled 



* Gaz. Chim. Ital., xli. (1911) 2, pp. 282-97, through Journ. Soc. Chem. Ind., 

 XXX. (1911) p. 1390. 



t Monatsh. Chem., xxxii. (1911) pp. 563-95, 597-608, through Journ. Soc. 

 Ohem. Ind., xxx. (1911) p. 1120. 



t Gaz. Chim. Ital., xli. (1911) 2, pp. 269-82, 314-18, through Journ. Soc. 

 Chem. Ind., xxx. (1911) p. 1391. 



§ Int. Journ. Metallography, ii. (1911) pp. 26-35 (4 figs.). Atti R. Accad. 

 Lincei, xx. (1911) pp. 927-31. See also this Journal, 1911, p. 712. 



II Journ. Chem. Soc, ci. (1912) pp. 50-56 (2.figs ). 



