PLATES. 



I. Illustrative of Mr. J. W. Clark's Paper on the Purification of Mer- 

 cury by Distillation in vacuo. 



II. Illustrative of Professor Tait's Paper on Listing's Topologie. 



III. Illustrative of Professor S. P. Thompson's Paper on a new Insu- 



lating Support. 



IV. Illustrative of Lord Rayleigh's Acoustical Observations. 



V. Illustrative of Professor P. Bunsen's Paper on the Condensation of 

 Carbonic Acid on Smooth Glass Surfaces. 



VI. Illustrative of Messrs. Wright and Thompson's Paper on the Deter- 

 mination of Chemical Affinity in terms of Electromotive Force. 



VII. Illustrative of Messrs. Lodge and Clark's Paper on the Phenomena 

 exhibited by Dusty Air in the neighbourhood of strongly Illumi- 

 nated Bodies. 



VEIL & IX. Illustrative of Mr. S. P. Langley's Paper on the Determina- 

 tion of Wave-Lengths in the Invisible Prismatic Spectrum. 



X. Illustrative of Dr. B. Hasselberg's Paper on the Second Spectrum 

 of Hydrogen, and Mr. J. J. Hood's Paper on the Pate of Chemical 

 Absorption of Gases, with regard to their In1 erdiffusion. 



XL Blustrative of Mr. S. Bidwell's Paper on some Experiments illus- 

 trating an Explanation of Hall's Phenomenon, 



XII. Illustrative of Professors Ayrton and Perry's Paper on Direct-Head- 

 ing Electro-Measuring Instruments, and a Non-Sparking Key. 



XIII. Illustrative of Mr. W. N. Shaw's Paper on a Practical Point in 



connexion with the Comparison of Resistances. 



XIV. & XV. Illustrative .of Mr. W. Baily's Paper on an Integrating 



Anemometer. 



XVI. Illustrative of Professor S. P. Thompson's Paper on a Modified 

 Resistance-Balance. 



