VI 
CONTENTS. 
Page 
Mr. R. Hunt’s Experiments and Observations on Light which 
has permeated coloured Media, and on the Chemical Action 
of the Solar Spectrum 267 
Mr. Weaver on the Mineral Structure of the South of Ireland, 
with correlative matter on Devon and Cornwall, Belgium, 
the Eifel, &c 276 
Dr. C. Schafhaeutl on the Combinations of Carbon with Silicon 
and Iron and other Metals, forming the different species of 
Cast Iron, Steel, and malleable Iron {continued) 297 
Dr. Roget’s Description of a Method of Moving the Knight 
over every Square of the Chess-board, without going twice 
over any one ; commencing at any given square, and end,- 
ing at any other given square of a different colour 305 
Mr. E. Solly’s Observations on the Precipitation of Copper by 
Voltaic Electricity 309 
Mr. A. Smee on the Galvanic Properties of the Metallic 
Elementary Bodies, with a Description of a new Chemico- 
Mechanical Battery 315 
M. Dumas’s Memoir on the Law of Substitutions, and the 
Theory of Chemical Types 322 
Proceedings of the Royal Society 329 
of the Royal Institution 338 
Theory of Substitutions. Pond Gas 339 
On Arsenic contained naturally in the Human Body 341 
Meteorological Observations for February, 1840 343 
Table 344 
NUMBER CIV.— MAY. 
Mr. Lyell on the Boulder Formation, or Drift and associated 
Freshwater Deposits composing the Mud- Cliffs of Eastern 
Norfolk 345 
Mr. R. Potter on the Method of performing the simple Experi- 
ment of Interferences with two Mirrors slightly inclined, so 
as to afford an experimentum crucis as to the nature of Light 380 
Mr. Weaver on the Mineral Structure of the South of Ire- 
land, with correlative matter onDevon and Cornwall, Belgium, 
the Eifel, &c. {continued) 388 
Mr. W.S. Harris on the Course of the Electrical Discharge, and 
on the Effects of Lightning on certain Ships of the British 
Navy {continued) 404 
Dr. R. Kane’s Remarks on the Compounds derived from the 
Stearopten of Oil of Peppermint 418 
Mr. A. Smee on the Galvanic Properties of the Elementary 
Bodies, and on the Amalgamation of Zinc 422 
Dr. C. Schafhaeutl on the Combinations of Carbon with Sili- 
con and Iron, and other Metals, forming the different species 
of Cast Iron, Steel, and Malleable Iron {continued) 426 
