354 



GALVANISM. 



the salt was decomposed, the base passing into or remaining in the negative, 

 and the acid in the positive cup. 



The time required for these transmissions appeared to increase, c&lens pari- 

 bus, as the space through which the decomposed elements were to be trans- 

 mitted increased. 



To determine whether the action of the metallic wires proceeding from the 

 Voltaic battery was immediately engaged in the production of these decompo- 

 sitions, the next experiments were arranged so that the electric current should 

 be transmitted to the solution to be decomposed through liquid conductors. 

 For this purpose, three cups (P, I, and N, fig. 6) were provided ; the extreme 



Fig. 6. 



ones P and N receiving the positive and negative wires from the battery, and 

 the cup I connected with each of them by amianthus. The cups P and N 

 were filled with purified water, and the solution to be decomposed was put into 

 the intermediate cup I. In every case the acid constituent of the solution was 

 decanted into P, and the alkaline into N. Lest the amianthus siphons should 

 have any mechanical effect on the transference of the solution between the 

 cups, the cups P and N were so filled that the surfaces of the water in them 

 were above that of the solution in I. 



As it was how abundantly apparent that the elements of the decomposed 

 substance were drawn from cup N through the interstices of the siphons, it Avas 

 determined to try how far this decanting power could be carried by breaking 

 the continuity of the siphons, and rendering it impossible for the decomposed 

 element to reach its destination without passing through an intermediate liquid. 

 For this purpose, the three cups being arranged as before, two of them, P and 

 I, were filled with distilled water, the water in I being tinged with litmus ; and 

 the negative cup N was filled with a solution of the sulphate of potash. If the 

 energy of the attraction of the positive wire for the acid constituent of the salt 

 were sufficiently strong to cause it to pass from N to P, through the liquid in 

 I, it was naturally expected that, on its route, its presence in I would be rendered 

 manifest by tiie usual effect of reddening the litmus. The acid passed from 

 N to" P through I, but without being manifested in I by any redness of the so- 

 lution. 



When the saline solution was put in the positive cup P, and the purified water 

 in the negative cup N, the water in I being tinged with turmeric, the alkali 

 passed in like manner from P to N without producing any effect on the color 

 of the liquid I. 



As the transmission of acid or alkali by means of the electric current through 

 water tinged with vegetable colors was effected without producing any sensible 

 change in these delicate tests of their presence, it was conjectured that, while 

 in this state of transition, or electrical progression, the chemical elements were 



