P L A T E S. 



I. & II. Illustrative of Prof. W. B. Morton and Mr. J. Vint's Paper 



on the Paths of tlie Particles in some cases of Motion of 

 Frictionless Fluid in a Rotating Enclosure. 



III. Illustrative of Prof. R. W. Wood's Paper on the Experi- 



mental Determination of the Law of Reflexion of Gas 

 Molecules. 



IV. Illustrative of Mr. C. E. Mendenhall and Prof. R, \V. Wood's 



Paper on the Effect of Electric and Magnetic Fields on 

 the Emission Lines of Solids. 

 A'. Illustrative of Prof. J. C. McLennan and Mr. H. Gr. Murray's 

 Paper on the Residual Ionization in Air enclosed in a 

 vessel of Ice. 

 VI. Illustrative of Mr. C. F. Meyer and Prof. R. W. Wood's 

 Paper on the Fluorescence produced by Ultra-Schumann 

 Hays. 

 VII. Illustrative of Prof. J, C. McLennan and Mr. C. G. Found's 

 Paper on the Delta Radiation emitted by Zinc when 

 bombarded by Alpha Rays. 

 Vril.-XII. Illustrative of Dr. A. C. Crehore's Paper on the Construction 

 of Compound Molecules with Theoretical Atoms, especially 

 the Systems of Growth of the Organic Compounds of 

 Carbon and Hydrogen. 

 XIII. Illustrative of Prof. J. C. McLennan and Mr. H. V. Mercer's 

 Paper on the Ionization Tracks of Alpha Rays in Hydrogen. 

 XIV. &XV. IUustrative of Prof. J. C. McLennan and Mr. R. 0. Dearie's 

 Paper on the Infra-red Emission Snectrum of the Mercury 

 Arc. 

 XVI. Illustrative af Prof. J. C. McLennan and Mr. E. Edwards's 

 Paper on the Absorption Spectra of Mercury, Cadmium, 

 and Zinc Vapours. 

 XVII. Illustrative of Mr. A. B. Wood's Paper on the Velocities of 



the a Particles from Thorium Active Deposit. 

 XVIII. Illustrative of Dr. L. Silberstein's Paper on Radiation from 

 an Electric Source, and Line Spectra. 



ERRATA. 



Page 126, third footnote, /or Descriptive read Disruptive. 



Page 129, fifth line after the table, for equation (4) read equation (3). 



Page 295: footnote %, for Phil. Mag. vol. xiii. p. 192 (1915) read 

 Phil. Mag. vol. xxx. p. 192 (1915). 



