1 76 Dr. Faraday's Experimeiital Researches in Electricity, 



the bubbles of gas rising from them did not obscure the cen- 

 tral parts of the liquid. 



952. A saturated sohition of sulphate of soda was put into 

 the cell, and the electrodes connected with a battery of 150 

 pairs of 4-inch plates: the current of electricity was conduct- 

 ed across the cell so freely, that the discharge was as good as 

 if a wire had been used. A ray of polarized light was then 

 transmitted through this solution, directly across the course 

 of the electric current, and examined by an analysing plate; 

 but though it penetrated seven inches of solution thus sub- 

 ject to the action of the electricity, and though contact was 

 sometimes made, sometimes broken, and occasionally re- 

 versed during the observations, not the slightest trace of 

 action on the ray could be perceived. 



953. The large electrodes were then removed, and others 

 introduced which fitted the ends of the cell. In each a slit 

 was cut, so as to allow the light to pass. The course of the 

 polarized ray was now parallel to the current, or in the direc- 

 tion of its axis (517.) 5 l^"t still no effect, under any circum- 

 stances of contact or disunion, could be perceived upon it. 



95't. A strong solution of nitrate of lead was employed 

 instead of the sulphate of soda, but the results were equally 

 negative. 



955. Thinking it possible that the discharge of the electric 

 forces by the successive decompositions and recompositions 

 of the particles of the electrolyte might neutralize and there- 

 fore destroy any effect which the first state of tension could 

 by possibility give, I took a substance which, being an ex- 

 cellent electrolyte when fluid, was a perfect insulator when 

 solid, namely, borate of lead, in the form of a glass plate, and 

 connecting the sides and the edges of this mass with the me- 

 tallic plates, sometimes in contact with the poles of a voltaic 

 battery, and sometimes even with the electric machine, for 

 the advantage of the much higher intensity then obtained, 

 I passed a polarized ray across it in various directions, as 

 before, but could not obtain the slightest appearance of action 

 upon the light. Hence I conclude, that notwithstanding the 

 new and extraordinary state which must be assumed by an 

 electrolyte, either during decomposition (when a most enor- 

 mous quantity of electricity must be traversing it), or in the 

 state of tension which js assumed as preceding decomposition, 

 and which might be supposed to be retained in the solid 

 form of the electrolyte, still it has no power of affecting a po- 

 larized ray of light; for no kind of structure or tension can 

 in this wav be rendered evident. 



