PLATES. 



I. Illustrative of Dr. F. Auerbach's Paper on the Passage of the 

 Galvanic Current through Iron. 



II. & III. Illustrative of Frederick Guthrie's Paper on the Fracture of 

 Colloids. 



IV. Illustrative of Professors Perry and Ayrton's Paper on a neglected 

 Principle that may be employed in Earthquake Measurements. 



V. Illustrative of Prof. D. E. Hughes's Paper on an Induction- 

 balance and Experimental Researches therewith. 



VI. Illustrative of Mr. W. C. Roberts's Paper on an Examination of 

 certain Alloys by the Aid of the Induction-balance. 



VII. Illustrative of Lord Rayleigh's Investigations in Optics, with spe- 

 cial reference to the Spectroscope. 



VIII. Illustrative of Prof. W. Grylls Adams's Paper on Measuring Po- 



lariscopes. m 



IX. & X. Illustrative of Mr. W. Baily's Paper on a Mode of producing 

 Arago's Rotation. 



XL Illustrative of Dr. C. Barus's Paper on the Relation between 

 the Thermoelectric Properties, the Specific Resistance, and the 

 Hardness of Steel ; and Mr. Louis Schwendler's on a new 

 Standard of Light. 



XII. Illustrative of Mr. W. Grant's Paper on the Conjugate Positions 

 of two Circular Coils of Wire. 



XIII. Illustrative of Messrs. Guthrie and Boys's Paper on Magneto- 



electric Induction. 



XIV. Illustrative of Prof. S. P. Thompson's Paper on the Action of 



Magnets on Mobile Conductors of Currents. 



