432 On the Influence of Light on the Polarized Electrode. 



August 24. Solution, water with 

 Sulphuric Acid. 



Deflection b}' polarization . 1 



Sunlight 5 



Blue glass 3 



Yellow glass 2 



Red glass 2 



Exposed platinum positive. 



August 25. Solution, water with 

 Sulphuric acid. 



Deflection by polarization . 2 



Sunlight 1 7 



Blue glass 45 



Yellow glass 3 



Red glass 3 



Exposed platinum positive *. 



September 4. Very dilute Muriatic 

 Acid. 



Deflection by polarization . 6 



Sunlight 14 



Blue glass 9 



Yellow glass 7'5 



Red glass , 7'5 



Diffuse daylight .... 8 

 Exposed platinum negative. 



September 6. Very dilute Nitiic 

 Acid. 



o 



Deflection by polarization . 1 



Sunlight 7 



Blue glass 3 



Yellow glass 2 



Red glass .1 



Exposed platinum negative. 



September 8. Dilute Nitric Acid. 

 Deflection by polarization . 3 



Sunlight fi 



Exposed platinum negative. 



Dilute Muriatic Acid. 



Deflection by polarization . 4 



Sunlight 10 



Blue glass 7 



Yellow glass G 



Red glass 6'5 



Exposed platinum negative. 



September 10. Dilute Nitric Acid. 



Deflection by polarization . 1 



Sunlight 5 



Exposed platinum positive. 



Dilute Muriatic Acid. Polished 

 platinum plates. 



Deflection by polarization . 1 

 Sunlight ...... 2 



Exposed platinum negative. 



September 14. Two sets, one of polisliecl, the other of platinized 

 platinum plates, in dilute si'iphuric acid without porous dia- 

 phragm. 



The polished plates gave — ^ 



Deflection by polarization . . 2 



With sunlight 3 



Platinized plates gave — ^ 



By polarization 3 



With sunlight 4 



The pair with black platinum was then tried with a porous 



cell ; and as it was not set aside for more than a few minutes to 



allow the polarization to subside, the ^ 



Deflection by polarization was . 15 



Increased by sunlight to ... 20 



Exposed platinum positive. 



* In a second cell with the same solution the exposed plate was nega- 

 tive, and tiie deflection increased by sunlight in the same du'cction as the 

 polarization, from 2° to 10°. 



