ZOOLOGY AND BOTANY, MICROSCOPY, ETC. L27 



on heating and cooling were determined by measuring the permeability 

 at different temperatures. The smooth and continuous freezing-point 

 curve shows a minimum at 70 p.c. nickel, at which concentration the 

 magnetic transformation temperature curve shows a maximum. These 

 facts point to the existence of FeNi 2 , but measurements of electrical con- 

 ductivity have afforded no indication of the existence of this compound. 

 Alloys containing less than 29 p.c. nickel are irreversible, those with 

 more nickel are reversible. 



Iron-nickel-copper Alloys.*— C. F. Burgess and J. Aston summarize 

 the results of their previous investigations on the mechanical properties 

 of the binary alloys of electrolytic iron with nickel and with copper, and 

 describe a similar investigation of a series of ternary alloys. Monel 

 metal is an alloy of nickel and copper obtained directly from the ore ; 

 the nickel content is about three times the copper content. The ternary 

 alloys were prepared by melting electrolytic iron with Monel metal, the 

 successive members of the series containing proportions of Monel metal 

 increasing by steps of 2 p.c. to 20 p.c. The curves showing the relation 

 of mechanical properties to proportion of alloy added are very similar 

 to the corresponding curves for the iron-nickel alloys. Copper does not 

 in general appear to have a deleterious effect, and when nickel + copper 

 does not exceed 10 p.c, the copper appears to be beneficial. 



G. A. Roush t gives the results of determinations of hardness by 

 means of the scleroscope, of binary and ternary alloys of iron with 

 nickel and copper, other properties of which have been determined by 

 Burgess and Aston. 



G. H. Clamer J and J. A. Matthews § give particulars of the pro- 

 perties of some copper-nickel steels. 



Arnold, J. 0. — A Fourth Eecalescence in Steel. 



[Attempts to explain an evolution of heat occurring between Ar 3 and Ar, in 

 a steel containing about - 2 p.c. carbon.] 



British Association, Sheffield, September 1910. 



Chappkll, C, & F. Hodson — Influence of Heat-treatment on the Corrosion. 



Solubility, and Solution Pressures of 8teel. Loc. cit. 



Ducelliez, F. — Alloys of Cobalt and Silver. 



Bull. Soc. Chim., vii. (1910) pp. 506-7. 



Mazzotto, D. — Heat of Solidification of Alloys of Lead and Tin. 



Nuovo Cim., xix. (1910) pp. 215-32. 



Yigotjroux, E.— Alloys of Nickel and Silver. 



Bull. Soc. Chim., vii. (1910) pp. 621-2. 



Pansais, E. — Variations in the Physical Properties of Metallic Alloys subjected 

 to Mechanical and Thermal Action. I. Specific Gravity. 



Gaz. Chim. Ital., xl. 1 (1910) pp. 431-3. 



* Met. and Chem. Eng., viii. (1910) pp. 452-6 (6 figs.). 



f Tom. cit., pp. 468-70, 522-3 (7 figs.). 



X Tom. cit., p. 527. § Tom. cit., pp. 527-8. 



