eind on a Battery mth invariable Currents. 361 



moistened with nitric acid; the other with clay moistened with 

 a solution of potash, and the intermediate glass tube with clay 

 moistened with a solution of sea-salt. The lower ends of the 

 platina tubes are closed with covers of the same metal pierced 

 with a great number of small holes. This end of the tube, 

 which is filled with the clay moistened with acid^ is plunged into 

 nitric acid, and the same end of the other into a solution of 

 potash. In order to facilitate the transmission of the electricity 

 from the clay to the sides of the tubes, the clay is mixed with 

 a certain quantity of finely divided platina, for the purpose of 

 increasing its conducting power. 



When those arrangements are made, platina wires are at- 

 tached to the extremities of the bent parts of the tubes for the 

 purpose of tmnsmitting the current through bodies. By com- 

 bining several apparatus of the same kind we have a pile the 

 effects of which are constant. 



One of these pairs required S^^'S (= '1232 grain) to pre- 

 vent the scales from turning. A galvanometer with a short 

 wire being placed in the circuit, exhibited during the same 

 time a deviation of 79°. In my memoir I have shown that 

 during a considerable space of time the effects of this pile un- 

 derwent no sensible variation. It is easy enough to account 

 for this invariability in its effects. We know that the decom- 

 posing metallic plates forming a part of a voltaic circuit, and 

 when plunged into a solution, are polarized in such a manner 

 as to produce a current in a direction contrary to that of the 

 pile. The polarization of each of these plates is manifested 

 in the deposition of a substance, which is transferred to its sur- 

 face by the current, and the nature of which depends on the 

 position of this plate with respect to the extremities of the pile. 

 So long as this substance remains in contact with the plate, 

 there is a current in a direction contrary to that of the original 

 current. But if the substance is surrounded by a body having 

 a close affinity with the substance, it enters into combination 

 with it, and the plate is immediately unpolarized. Such is 

 precisely the case with the different elements of the pile which 

 we describe. The alkali which is transferred to the negative 

 plate combines immediately with the surrounding acid, and 

 the alkali deposited on the positive plate is neutralized by the 

 acid which surrounds it. 



I have entered into some detail respecting the electro-che- 

 mical effects of the polarization of the decomposing plates, 

 when they transmit constant currents produced by an appa- 

 ratus consisting of one, two, three, and four pairs. I then set 

 forth the result of the first experiments, which I made with 

 the kinds of apparatus already described, in order to establish 



Third Series, Vol. 10. No. 62. May 1837. 3 A 



