PLATES. 



I. Illustrative of Prof. R. W. Wood's Paper on Optical Pro- 

 perties of Homogeneous and Granular Films of Sodium 

 and Potassium. 

 II. & II [. Illustrative of Prof. Barton and Miss Browning's Paper 

 on the Resonance Theory of Audition subjected to Ex- 

 periments. 

 [IV. Illustrative of Mr. S. K. Mitra's Paper on the Large- Angle 

 Diffraction by Apertures with Curvilinear Boundaries. 

 V. Illustrative of Prof. W. E. Adeney and Mr. H. G. Becker's 

 Paper on the Determination of the Rate of Solution of 

 Atmospheric Nitrogen and Oxygen by Water. 

 VI. Illustrative of Prof. Barton and" Miss Browning's Paper on 

 a Syntonic Hypothesis of Colour Vision with Mechanical 

 Illustrations. 

 VII. Illustrative of Messrs. A. Bursill and II. Bedson's Paper 



on a New Magnet- testing Instrument. 

 VIII. Illustrative of Prof. Kia-Lok Yen's Paper 0:1 an Absolute 

 Determination of the Coefficients of Viscosity of Hydrogen, 

 Nitrogen, and Oxj'gen. 

 IX. Illustrative of Dr. F. W. Aston's Paper on a Positive Ray 

 Spectrograph. 



ERRATUM. 



P. 305. The remark at the bottom of the page commencing " There 

 appears to be " refers to m = o and should be transferred to after 1*4 on 

 the next page. 



