ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 97 



METALLOGRAPHY. 



Defects arising- iu Steel during Fabrication. — Austin R.Wilson 

 {Chemical itnd Metalliin/lcal Kiujlaeeriim, Dec. 22, 11)20, 23, No. 25). 

 Microscopic appearances caused by surface defects, cold-working, over- 

 heating;, and burning. Nuclei of fatigue fractures are associated with 

 phosphorus bands. Photographs of changes in structure during anneal- 

 ing of steel castings are also given. 



Effect of Iron on Brass. — 0. S>l\lley {Melal Indmtrij, Nov. 26, 

 1920. 17, No. 22). The author concludes that small quantities of iron 

 improve the hardness and strength and shock-resisting properties of 

 brasses, aud discusses its effects upon the working of both cast and 

 wrought l)rass. 



Polarized Lig-ht in the Study of Ores and Metals.— F. E. Wright 

 {Froc. Amer. Phil. Soc, 191'.), 58). 



Examination of Ores and Metals in Polarized Light. — F. E. 

 Weight (Minin// and Metallurgy, 1920, No. 15s). 



Metallography of Arc-fused Steel. — Henry S. Rawdon, Edward 

 C. CtRoesbeck, and Louis Jordan {Chemical and MeUdlarcjical En- 

 gineerinij, Oct. 20, 1920, 23, No. 16). Various lines of investigation 

 are utilized to support the idea that microscopic " plates " existing in 

 fusion welds are due to nitrogen ; that the plates are very persistent , and 

 are not responsible for the low ductility of the metallic piece. 



Diffusion of Solid Copper in Liquid Aluminium. — Robert J. 



Anderson {Chemical and Mel all urn iced Engineering, Sept. 22, 1920, 23, 

 No. 12). Details of experiments where copper rods were dipped in 

 molten aluminium under definite conditions, and the resulting alloy 

 analysed. Filiation experiments also were made in various ways, all 

 giving nearlv the same results. 



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Manufacture of Rich Copper : Aluminium Alloys or Hardeners. — 

 Rokt. J. Anderson {Chemical and Metallurgical Engineering, Sept. 29, 

 1920, 23, No. 13). Describing the methods in use in aluminium 

 foundries of the United States for manufacturing rich alloys of copper 

 and aluminium, and details of experiments carried out for the purpose 

 of comparing different methods. 



Quenching- of Carbon Steels.— Portevin and Garvin {Bulletin 

 de la Sociite d' Encouragement pour rindustrie Nationale, May-June, 

 1920). This study deals mainly with the conditions under which 

 troostite and martensite are formed. F. L G. R. 



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