ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 387 



absorbed by the iron. Experiments in which iron was carburised by 

 heating in contact with sugar charcoal, and wood charcoal, showed that 

 the formation of gaseous compounds was not necessary for cementation 

 to take place. 



L. Guillet * replies to Ledebur's criticisms. He has shown that the 

 active agent in cementation is always a cyanide or a carbide, and that 

 carbon alone is not absorbed when heated in contact with iron. Ledebur's 

 proofs to the contrary are inconclusive. 



Andrews, T. — Microscopic Observations on Naval Accidents. 



Engineering, lxxix. (1905) pp. 563-6 (16 figs.), 

 and lxxx. (1905) pp. 235-9 (24 figs.). 

 Berthelot & G. Andre — Becherches sur quelques metaux et minerais trouves 

 dans les fouilles da Tell de l'Acropole de Suse en Ferse. 



Comptes Rendus, cxlii. (1906) pp. 473-80. 



De Freminville, 0. — Influence des vibrations dans les pbenomenes de fragilite. 



Rev. Metallurgie, iii. (1906) pp. 109-21 (3 figs.). 

 Sankey, H. R. — Impact Testing. Eng. Mag., xxx. (1906) pp. 913-14. 



Waterhouse, G. B. — Nickel Steel, and its Application to Boiler Construction. 



[Nickel steel, especially that containing about 30 p.c. nickel, has properties 

 which render it highly suitable for boiler construction.] 



Iron and Steel Mag., xi. (1906) pp. 301-7. 



* Rev. Metallurgie, iii. (1906) pp. 227-8. 



