ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 573 



Metallography, etc. 



Arsenic-antimony Alloys.* — N. Parravano and P. de Cesaris have 

 ascertained, by thermal and microscopical methods, that arsenic and 

 antimony form a continuous series of solid solutions in the range inves- 

 tigated, to Sb p.c. arsenic. Sections were etched in the fumes from 

 aqua regia. 



Cadmium-tin System. f — A. P. Schleicher has used microscopical as 

 well as thermal methods to determine the equilibrium diagram more 

 accurately. The sections were etched with a solution prepared by adding 

 a few drops of saturated aqueous solution of stannous chloride to 20 c.cm. 

 alcohol. This preparation colours cadmium black and leaves tin un- 

 affected. (Jadmium retains only very small amounts of tin in solid 

 solution ; y-tin may hold up to about 10 atomic p.c. cadmium in solid 

 solution ; /?-tin much less. 



W. Guertler | discusses Schleicher's results, pointing out the effect of 

 incomplete attainment of equilibrium iipon micro-structure as well as 

 upon thermal phenomena. The aggregate resulting from the decom- 

 position of y crystals into ^-tin and cadmium, being formed at a low 

 temperature, is ultra-microscopic in structure and resembles troostite. 

 In discussing some theoretical points the author shows how surfusion 

 effects may induce the formation of a purely eutectic structure in a con- 

 centration which is not that of the pure eutectic. The attraction exerted 

 by primary crystals upon the corresponding constituent of a eutectic 

 crystallizing around those primary crystals, causes the formation of 

 sheaths of the other constituent. 



Gold-silver Alloys. § — ^U. Raydt has shown by thermal methods 

 that gold and silver form a continuous series of mixed crystals. In 

 consequence of the smallness of the crystallization interval, the crystals 

 are nearly homogeneous. The cored structure, when present, was found 

 to persist after annealing. A suitable etching reagent was not found 

 for alloys containing more than 60 p.c. gold. 



Copper Alloys. II — E. Miinker has determined numerous physical 

 properties of three series of binary alloys, copper-phosphorus, copper- 

 manganese, and copper-tin, the amount of the element added to copper 

 not exceeding 1 • 5 p.c. The influence of annealing upon the micro- 

 structure of cold worked specimens was studied, and is illustrated by 

 photomicrographs. 



Ternary System Copper-zinc-aluminium. — In the course of a deter- 

 mination of the equilibrium diagram of the copper-rich region of this 



* Int. Zeitschr. Metallographie, ii. (1912) pp. 70-5 (4 figs.). 



t Int. Zeitschr. Metallographie, ii. (1912) pp. 76-89 (9 figs.). 



X Int. Zeitschr. Metallographie, ii. (1912) pp. 90-102, 172-7 (8 figs.). 



§ Zeitschr. Anorg. Chem., Ixxv. (1912) pp. 58-62 (4 figs.). 



II Metallurgie, ix. (1912) pp. 185-98 (37 figs.). 



