ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 81 



METALLOGRAPHY, Etc. 



Decomposition of Metals. — Colonel A. I. Krynitzky {Chemical 

 and Metallurgical Engineering, 20, No. 6, March 1919). A critical 

 review of various theories which have been advanced from time to time 

 to explain the so-called " Disease of Metal." Allotropy, recrystalliza- 

 tion, corrosion, and season cracking may each be responsible for some 

 types of such failures. 



Etching- Media commonly used in Non-ferrous Metallography. 

 — J. Smout {The Metal Industry, 1918, 14, No. 1). A few of the 

 difiPerent classes of etching. Describes etching media used for copper, 

 brass, bronze, nickel, G-erman silver. 



Rapid Recrystallization in Deformed Non-ferrous Metals. — 

 D. Hanson {The 3Ietal Imlustry, 1918, 13, 183) describes recrystalliza- 

 tion phenomena of aluminium, magnesium, zinc, lead, copper and 

 certain alloys of the same. 



The Metallography of Aluminium.— Robert J. Anderson {The 

 3Ietal Industry, 14, No. 1;!, March 1919). Exaggerated growth in 

 aluminium. Silver bands in aluminium. Polishing and etching 

 aluminium. 



The Micrography of Aluminium and its Alloys. — D. Hanson 

 and S. L. Archbutt {The Metal Industry, 14, No. 14, April 4, 1919). 

 Preparation of sections. The micrographic constituents of aluminium 

 alloys. Pure aluminium. Copper-aluminium alloys. Zinc-aluminium 

 alloys, magnesium-aluminium alloys, manganese-aluminium alloys. 



A Few of some of the Mechanical Properties of the Alloys of 

 Copper and Zinc— F. Johnson {The Metal Industry, 13, 188-190) 

 describes certain tests made by members of the Metallurgy Department 

 of the Birmingham Technical School, showing relations between Brinell 

 hardness, scleroscope hardness, tensile tests, microscopic examination and 

 analytical examination of parts as cast and after annealing. 



The Properties of some Copper Alloys. — AV. Rosenhain, B.A., 

 and D. Hanson {The Metal Industry, 14, No. 14, April 14. 1919). 

 Alloys of copper with aluminium, with manganese and aluminium, 

 not containing zinc. Alloys free from aluminium. 



Effect of Heat Treatment on Bronze. — F. F. Hausen and 0. A. 

 Knight {The Iron Age, 1919. 103, No. (i, 347). Characteristics dis- 

 closed by Brinell hardness tests and photomicrographs. Quenching 

 and drawing give greater hardness than quenching alone. 



