ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 795' 



etching reagents tried, three were found to be specially useful — hydro- 

 gen, water vapour, and an organic acid (such as tartaric acid) in the 

 form of a solution in water. The two gaseous reagents were applied by 

 passing them over the heated section. The constituents of ferruginous 

 slags may be classified into three groups : — 1. Bodies not attacked by 

 any of the three etching reagents ; these are silicates of iron and silicates 

 of manganese. 2. Bodies attacked by hydrogen and water vapour, but 

 not by organic acids ; these are the oxides. 3. Bodies attacked by 

 organic acids, but not by the two gaseous reagents ; these are the 

 sulphides of iron and of manganese. Methods of distinguishing iron 

 from manganese in the various compounds are given. 



Guye, C. E., & H. Schappeb — Internal Friction of some Metals at Low Tem- 

 peratures. Archives des Sciences physiques et naturelles {Geneva) 



xxx. (1910) pp. 133-51 (23 figs.). 



Hegg, F.— Thermomagnetic Study of Ferro-nickels 



Tom. cit., pp. 15-45 (17 figs.). 



Turner, L. B. — Stresses in a thick hollow Cylinder subjected to Internal 

 Pressure. Trans. Cambridge Phil. Soc, xxi. (1910) pp. 377-96 (8 figs.). 



Arnold, J. 0. — Uniform Nomenclature of Iron and Steel. 



Journ. Iron and Steel Inst., lxxxi. (1910) pp. 185-205 (2 figs.). 



Arnold, J. 0., & A. A. Read — Chemical and Mechanical Relations of Iron, 

 Manganese, and Carbon. Tom. cit., pp. 169-84 (7 figs.). 



Smith, C. A. M.— Elastic Breakdown of Certain Steels. 



Tom. cit., pp. 431-66 (31 figs.). 



Tagueeff, G.— Homogeneity of Metals. Tom. cit., pp. 467-89 (10 figs.). 



3 G 2 



