ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 89 



Metallography, etc. 



Arsenic in Commercial Copper.* — P. Jolibois and P. Thomas have 

 studied the microstructure of copper- oxygen, copper-arsenic, and copper- 

 oxygen- arsenic alloys, to ascertain if copper can be deoxidized by 

 additions of arsenic. It was found that arsenic additions did not affect 

 the quantity of cuprous oxide present in oxygen-containing copper, but 

 altered the appearance of the cuprous oxide globules, causing (hem to be 

 larger and less numerous. Arsenic forms copper arsenide which enters 

 into solid solution in copper, and accordingly does not deoxidize 

 copper. Antimony has a similar effect. Tin, zinc, and magnesium 

 remove oxygen from copper, and lead has some deoxidizing effect. 

 Ammoniacal cupric chloride solution was used for etching. 



Acicular Constituents of Alloys.| — F. Robin describes in detail 

 constituents which appear in the form of needles in copper-aluminium 

 and copper-tin alloys, and in special bronzes obtained by adding another 

 element to one of these binary alloys. The mode of formation of 

 martensite-like constituents, their true constitution, and the structural 

 modifications which they undergo when heated, are discussed. Acicular 

 constituents occur only in a few series of alloys, and appear to be 

 dependent on the quenching of a solid solution which is unstable at 

 ordinary temperatures. The reagent used for etching the aluminium 

 bronzes was made up of ferric chloride 5 p.o, water 5 p.c, hydrochloric 

 acid 30 p.c.,isoamyl alcohol 30 p.c, ethyl alcohol 30 p.c, and was found 

 to be suitable for all copper alloys, and for nickel. 



Manganese-silver Alloys. J — G. Arrivaut, in the course of an 

 investigation of this binary system, has studied the microstructure of the 

 alloys prepared. The manganese-silver system is peculiar in that the 

 compound found, MnAg , forms a continuous series of solid solutions 

 with silver, but is nearly insoluble in manganese. 



Microscopical Examination of Standard Steels.§ — H. S. Rawdon 

 describes the microstructure of specimens which had been used for 

 taking heating and cooling curves of a number of steels supplied by 

 H. M. Howe, and containing 0'03 to 1'45 p.c. carbon. Though the 

 thermal treatment had been carried out in a high vacuum, there was 

 distinct evidence of slight decarburization of the surface. 



So-called Fibrous Structure in Steel. || — The arrangement of the 

 constituents in a section taken from a steel casting which has been 



* Rev. Metallurgie, x. (1913) pp. 12G4-70 (14 figs.). 



t Bull. Soc. d'Encouragement, cxix. (1913) pp. 12-41 (29 figs.). 



X Rev. Metallurgie, x. (1913) pp. 1257-63 (8 figs.). 



§ Bull. Amer. Inst. Min. Engineers, No. 78 (1913) pp. 1095-S (6 figs.). 



|l Zeitschr. Anorg. Chem., lxxxi. (1913) pp. 156-69 (22 figs.). 



