chemical Agencies of Electricity. 23 
through the water to the positive side would redden the 
litmus in its course, some slips of moistened paper tinged with 
litmus were placed above and below the pieces of amianthus, 
directly in the circuit. The progress of the experiment was 
minutely observed ; the first effect of reddening took place 
immediately above the positive surface, where I had least 
expected it ; the red tint slowly diffused itself from the po- 
sitive side to the middle of the vessel, but no redness appeared 
above the amianthus, or about it, on the negative side, and 
though it had been constantly transmitting sulphuric acid, it 
remained unaffected to the last. 
The order of the experiment was changed, and the saline 
solution placed on the positive side ; a solution and papers 
tinged with turmeric being substituted for those tinged with 
litmus. The effect was precisely analogous ; the turmeric be- 
came brown first, near the negative wire, and no change took 
place in the intermediate vessel near the positive wire. 
In another process, the two glass tubes were filled with 
solution of muriate of soda, and the intermediate vessel with 
solution of sulphate of silver ; paper tinged with turmeric was 
placed on the positive side, and paper tinged with litmus on 
the negative side ; as soon as the electrical circuit was com- 
plete, soda began to appear in the negative tube, and oxy- 
muriatic acid in the positive tube ; and the alternate products 
were exhibited passing into the solution of sulphate of silver, 
the muriatic acid occasioning a dense heavy precipitate, and the 
soda a more diffused and a lighter one ; but neither the turmeric 
transmitting the alkali, nor the litmus transmitting the acid, 
had their tints in the slightest degree altered. 
