ZOOLOGY AND BOTANY, MICEOSCOPY, ETC. 755 



vegetable micro-chemistiT, which was given to the students who desired 

 to present themselves for the Doctorat en .Sciences at the University of 

 Brussels. 



Prowazek's Manual of Microscopical Technique.* — S. v. Prowazek's 

 little manual for the microscopical technique of Protozoa, is principally 

 intended for medical men, though it also appeals to zoologists. It deals 

 with the mode of examination in living and fixed preparations of 

 Rhizopoda, Mastigophora, Sporozoa, and Ciliophora. 



AVoiTHE — Vorrichtungeii zuni gefahrlosen Befestigen und aufspannen wilder 

 Ratten. [Description of apparatus foi- fastening and extending rats for labora- 

 tory pnrposes.] Centralbl. Bakt. Orig., Ite Abt., xliv. (1907) 



pp 709-19 (11 figs.). 



Metallography, etc. 



Alloys of Aluminium and Copper.! — H. C. H. Carpenter and 

 C. A. Edwards have carried out an extended investigation of this series. 

 Forty-eight alloys were examined. The work consisted chiefly of, 

 determination of the mechanical properties of the industrially useful 

 alloys — i.e. those lying outside the range 11-96 p.c. aluminium. The 

 equilibrium diagram was also worked out, and the microstrucfcure of the 

 alloys studied. Alloys with 0-8 p.c. Al have a low yield point, moderate 

 ultimate stress and high ductility, and are not sensitive to heat treat- 

 ment. From 8-11 p.c. Al the ultimate stress is high, yield point rela- 

 tively low, ductility good from S-10 p.c. Al. Alloys in this class are 

 hardened by chilling from above 800° C, and considerably affected by 

 other forms of heat treatment. The increase of hardness occurring at 

 about 8 p.c. Al coincides with the appearance of a dark, acicular con- 

 stituent. Alternating stress tests in the Stanton machine showed that 

 the ratio 



maximum range of stress 

 primitive yield point (in tension) 



increased from 1*3 in the alloy with • 1 p.c. Al to the remarkably high 

 figure of 1 • 9 in the 9 • 9 p.c. alloy. The addition of copper to aluminium 

 progressively raises the tenacity up to 4 p.c. copper, ductility correspond- 

 ingly falling. The authors consider that the great evolution of heat 

 resulting from the addition of aluminium to molten copper, is due to 

 oxidation of the aluminium by copper oxide dissolved in the copper. It 

 is suggested that the growth of size of crystal observed on remelting 

 certain alloys is due to the persistence of crystalline orientation in the 

 molten state — i.e. to the occurrence of " liquid crystals." The etching 

 reagents used were sodium hydrate solution for aluminium and the 

 aluminium-rich alloys, ferric chloride in dilute hydrochloric acid for 

 the copper-rich alloys, and for copper, concentrated nitric acid followed by 

 washing in a heavy stream of water on the commencement of chemical 

 action. A comparison is drawn between the equilibrium diagram and 



* Leipzig : J. A. Earth, 1907, 66 pp. 



t Proc. Inst. Mech. Engineers, 1907, i. pp. 57-378 (204 figs ). (Eighth Report 

 to the Alloys Research Committee.) 



Dec. 18th, 1007 -i d 



