ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 195 



Embrittling 1 of Brass.* — D. Meneghini examined worked brass 

 (parts of incandescent gas-burners) which had become brittle in use, in 

 some cases fracturing spontaneously. No change in composition was 

 detected ; the brass contained 35 p.c. zinc, 0'3 to 0*4 p.c. lead, and 

 consisted almost wholly of the a solid solution. The softening resulting 

 upon annealing at 700" 0. indicated that the brass had been hardened 

 by cold-work. The brittleness is ascribed to the effect of sulphur 

 dioxide and moisture acting on brass in which internal stresses, caused 

 by cold-work, existed. 



Removal of Sulphur from Silver. f — C. C. Bissett has investigated 

 the possibility of removing sulphur from silver by additions of copper or 

 iron, and records some observations of structure of the melts prepared. 

 When copper was added in increasing amounts to molten silver contain- 

 ing 13*5 p.c. of silver sulphide, the amount of sulphide remained fairly 

 constant until 2 p.c. copper had been added. Further additions reduced 

 the amount of sulphide, and the addition of more than 3"5 p.c. copper 

 removed all the sulphide from the silver. When iron was added to 

 molten silver containing 11*6 p.c. of silver sulphide, two liquid layers 

 were formed, as in the case of copper additions, the upper rich in sulphur, 

 the lower rich in silver. When a considerable excess of iron beyond 

 that required to saturate the whole of the sulphur present was added, the 

 upper layer contained all the sulphur, and the lower layer all the 

 silver. 



Copper-zinc-lead Alloys.J — N. Parravano has studied the equili- 

 brium of the copper-zinc system and the copper-zinc-lead system. Lead 

 does not dissolve, in the solid state, in the a or y copper-zinc solid 

 solutions, and in lead brasses is found admixed mechanically with the 

 copper-zinc alloy. 



Widmanstatten Structure in Alloys. § — N. T. Belaiew points out 

 that the Widmanstatten figures found in steel prepared under certain 

 conditions are formed by the distribution of the structural elements 

 between the cleavage planes during recrystallization, and are character- 

 istic of the primary octahedral crystallization of the iron. Similar 

 structures should occur in other alloys which crystallize in the regular 

 system and undergo recrystallization after solidification ; the primary 

 octahedral crystals of the solid solution should throw out secondary 

 deposits on their cleavage planes during recrystallization. A number of 

 examples (brasses, bronzes, platinum-aluminium alloys, etc.) are illus- 

 trated by photomicrographs. 



Coating Metals with Aluminium Alloy. ||— H. B. 0. Allison and 

 L. A. Hawkins describe a process in which articles of copper, iron or 



* Annali. Chim. Appl. ii. (1914) pp. 154-8, through Journ. Chem. Soc., cvi. 

 (1914) p. 849. 



t Journ. Chem. Soc, cv. (1914) pp. 2829-36 (2 figs.). 



J Gaz. Chim. Ital., xliv. (1914) ii. pp. 475-502, through Journ. Soc. Chem. Ind. 

 xxxiv. (1915) p. 86. 



§ Journ. Inst. Metals, xii. (1914, 2) pp. 46-55 (14 figs.). 

 Met. and Chem. Eng., xii. (1914) p. 730. 



