ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 125 



Contributions to the Study of Alloys of Aluminium and Silicon.* 

 Vigouroux and Arrivault find that |the lack of durability often met 

 with in vessels made of commercial aluminium is due to the presence 

 of minute crystals of silicon, or of the eutectic silicon alloy. The two 

 elements act as the poles of a battery, and set up rapid corrosion. 



Primary and Secondary Devitrification in Glassy Igneous Rocks.f 

 T. G. Bonney and J. Parkinson point out analogies between these 

 phenomena and those observed in the micro-chemistry of alloys. Just 

 as important changes take place after solidification in copper-tin alloys, 

 so that the structures and compounds produced at earlier stages of con- 

 solidation disappear, to be replaced by later products ; so not improbably 

 similar changes would be found to have taken place in many rocks. 



Metallography of Nickel Steels.* — L. Cuillet has made a very com- 

 plete set of observations on steels containing nickel varying in amount 

 from zero to 90 p.c. The observations included : — 



(1) Microstructure of cast steels. (2) Microstructure of quenched 

 steels. (3) Microstructure of reheated steels. (4) Microstructure of 

 cold-worked steels. (5) Microstructure of steels cooled below atmo- 

 spheric temperature. (6) Cementation and decarbonisation of nickel 

 steels. (7) Research on the regeneration of quenched steels. (8) Con- 

 elusions. 



His conclusions are that the constituents of nickel steel are : — 



(1) Ferrite, pearlite, and, of course, troostite and sorbite. (2) 

 Martensite. (3) Acicular crystals, which appear after etching, some- 

 times white, sometimes black, although the reason for this phenomena 

 is not known. (4) Polyhedric grains, undoubtedly corresponding to 

 Mr. Osmond's iron. 



The acicular crystals are probably hardenite, another form of 

 martensite. 



Ashe, A. — Photography of Cavities in Minerals and the Determination of the Con- 

 densation Points of the Enclosed Gases. 



Joum. Quekett Micro. Club, viii. (1903) pp. 545-S (1 pi.). 



ISeck, W. T. — Preparation of Samples for Microscopic Analysis, as followed by 

 the "Westinghouse Ele trie and Manufacturing Company. 



l'roc. of Engineers' Soc. of Western Pennsylvania, Dec. 1902. 

 Metalhgraphist, vi. (Oct. 1903) pp. 320-2. 

 Lac, F. C. — Tests on Finishing and Annealing Heats. 



Sparks from the Anvil, Oct. 1902. 

 Melallographist, vi. (Oct. 1903) pp. 322-7 (6 figs.)- 



Wood worth, J. V.— Hardening, Tempering^ Annealing, and Forging of Steel. 



[Favourably reviewed by J. O. Arnold in Nature, lxix. No. 1780 (Dec. 10, 

 1903) p. 124.] Constable & Co., 2S8 pp. 



* Proces-Verbaux des Seances de la Soc. des Sciences de Bordeaux, 1901-2, 

 pp. 20-3, 3 plates f 6 pliotomicos. 



t Quart. Joum. Geol. Soc, lix. (Nov. 1903) pp. 428-44, 1 plate of 6 photomieros. 



j Bull, de la Soc. d' Encouragement, May 31. 1903; Metal lograpbist, vi. (Oct. 

 1903) pp. 274-302 (40 figs.). 



