PROCEEDINGS OF THE SOCIpyrY. 361' 



to purchase a desiccator in which the specimens may be kept free from 

 rust and tarnish. The application of varnish to the faces is not to 

 be recommended as a preservative. Either it must be dissolved off 

 each time the sample is examined, or else applied as I described in a 

 communication some time ago, which process is risky and not very 

 satisfactory. I have had these sections under observation for some 

 time, and I am hopeful that the method adopted will prove efficacious. 

 Owing to the great delicacy of the surfaces, it will be understood 

 that the greatest care is necessary in handling, as the infliction of a 

 scratch means repolishing and etching. 



With a view to making the collection generally useful, a vertical 

 illuminator has been acquired for the Society. This, of course, is quite 

 essential. 



In the near future the question of a suitable light-source will 

 need consideration. Personally I have obtained excellent results with a 

 200 c.p. J -watt lamp. These lamps are very moderate in cost, and 

 highly convenient. It is possible to use our existing lamps, though 

 this is not easy. The vertical illuminator fixes successfully to one of 

 the Society's stands, and it is nat essential to use specially mounted 

 ol:>jectives. 



All things considered the Society may be congratulated upon its new 

 possession. If it is appreciated, il will not be difficult, I expect, to 

 obtain additions from time to time. 



ANNOTATED LIST OF METALLURGICAL SPECIMENS PRESENTED 



TO THE ROYAL MICROSCOPICAL SOCIETY BY 



SIR ROBERT HADFIELD. 



1. "AR:>rco" Irox. — i?. iVr?.-'- : 2148. Analysis-, c.c.f 0.03 p.c, 



Mn 0-015 p.c. Treafmmt : As forged. Mag.X : x 100. 



Polyhedral grains of " ferrite " (pure alpha iron). The individual 

 grains are unequally coloured owing to difference of orientation of the 

 crystalline elements composing them. The boundaries of the grains are 

 developed on etching owing to minute differences of potential. 



Eef.^ : " Metallography and Heat Treatment of Iron and Steel " 

 (Sauveur) [hereinafter called " Metallographv " (Sauveur)], 

 p. 101, fig. 116 ; '^Metallography " (Desch), p. 860, pi. xiii.A. 



2. "B.B." Wrought Iron. — R.JS^o. : 2112. Analysis: cc. 0*06 p.c, 



Mn • 05 p.c. Treatment : As forged. May. : x 70. 

 Very typical structure of wrought iron. This is a longitudinal 

 section consisting of " ferrite " and layers of slag, which latter are the 



* B. No. = Reference Number. 



+ cc. = combined carbon. 



X Mag. = Suitable magnification. 



§ Bef. = References to well-known treatises where descriptions of the structure 

 (together with further details than here given) may be found. Where references 

 to figures are given, these illustrate appropriately the particular structure in 

 question. 



