ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 529 



C. F. W. Rys * points out that the use of plasticine for mounting is 

 not new, and describes the well-known method, given by J. B. Stead in 

 1900, in which parallelism of slide and polished face is obtained by 

 means of a brass ring in a much simpler manner than that described 

 by Preuss. 



Electron Theory and Solid Solutions of Metals.f — R. Schenck 

 attempts a theoretical explanation of the diminution of electrical con- 

 ductivity and of the increase of the ratio of the thermal to the electrical 

 conductivity in the case of metallic solid solutions. The decrease in 

 electrical conductivity appears to be due to increased viscosity. 



" Damping " Test of Metals. J — 0. Boudouard has devised methods 

 for recording photographically the curve representing the damping of 

 the vibrations set up by means of an electromagnet in a steel bar. A 

 steel containing ■ 3 p.c. carbon was tested (1) as rolled, (2) annealed, 

 (3) hardened. 



Thermo-electric Properties of Metallic Alloys. § — W. Haken has 

 determined the thermo-electric forces produced at the junctions of 

 copper with alloys belonging to the binary systems tellurium-antimony, 

 tellurium-tin, tellurium-bismuth, tellurium-lead, antimony-silver, copper- 

 phosphorus. The curves representing the relation between composition 

 and thermo-electric properties, and between composition and electrical 

 conductivity, are compared with the equilibrium diagrams obtained by 

 thermal methods. The existence of compounds and of solid solutions 

 is indicated by the thermo-electric method, which may accordingly be 

 employed to check the conclusions drawn from thermal investigations. 



Thermo-electric Properties of Alloys. || — W. Broniewski has collated 

 published data relating to the thermo-electric properties of alloys. By 

 comparing curves representing these properties as a function of the com- 

 position of binary systems, with the equilibrium diagrams obtained by 

 thermal and other methods, he arrives at certain general laws. The 

 author's conclusions are too lengthy for reproduction ; he considers that 

 the determination of thermo-electric properties may be a useful auxiliary 

 method for the study of alloys. An extensive bibliography is appended. 



Homogeneity of Metal s.1[ — G. Tagueeff discusses the causes and 

 the effects of non-homogeneity of metals, having regard especially to 

 steel rails. Fracture under shock, and unequal wear, are in general due 

 to non-homogeneity. The presence of manganese sulphide is detri- 

 mental. 



Change of State in Metals under Mechanical Strain.** — A. Martens 

 discusses in a general manner the behaviour of metals under tension, 



* Stahl und Eisen, xxix. (1909) pp. 555-6 (3 figs.). 



t Ann. Physik., xxxii. (1910) pp. 261-90, through Journ. Chem. Soc, xcviii. 

 (1910) p. 482. % Comptes Rendus, cl. (1910) pp. 696-8. 



§ Ber. Deutsch. Phys. Ges., 1910, pp. 229-39, through Journ. Chem. Soc, 

 xcviii. (1910), p. 387. 



|| Rev. Me'tallurgie, vii. (1910) pp. 341-67 (15 figs.). 



4 Proc. Int. Assoc, for Testing Materials, No. 15 (1910) 4 pp. 

 ** SB. k. Preuss. Akad. Wiss., 1910, pp. 209-20 (9 figs.). 



Aug. 17th; 1010 2 n 



