NATURAL PHILOSOPHY. 



NEW ARRANGEMENT OF THE VOLTAIC PILE. 



M. LA GRANGE in the Comptes Rend us of April 5th, states that 

 he has found a means of rendering the current of the voltaic pile per- 

 fectly constant and invariable, even for weeks or months, of whatever 

 metals the electrodes may be formed, and whether they be set in 

 action by two liquids as in the combination of Bunsen, or by one, as 

 in that of Volta. This continuity of electric action is obtained in the 

 same way that we obtain the continuity of the calorific action of a 

 stove, which is furnished below with a grating to let the ashes fall, 

 whilst we continually add fuel at the top. The method which he 

 employs is simple and fulfils all the conditions which can render it 

 practicable in an industrial point of view instead of increasing the 

 expense it diminishes it. 



Let us first see the disposition of a single pair with one liquid. 

 Take a vessel with a hole in the centre of the bottom, such as a flower 

 pot, and round the hole let one end of a cylindrical diaphragm of 

 cloth be attached by cement to the bottom of the pot. The axis of 

 the hollow cloth cylinder when erect, will coincide with the axis of 

 the vessel, and its height is somewhat less than the walls of the latter. 

 Within the diaphragm is placed a stick of very hard coke, such as is 

 found in the gas-retorts, surrounded by small grains of the same coke, 

 and round the diaphragm a cylinder of amalgamated zinc, and some 

 acidulated water, furnished drop by drop from a reservoir above. 

 Let us now unite the two poles by a conducting wire, and see what 

 takes place in the interior of the apparatus. The acidulated water, 

 which continues to drop into the vessel, will pass in part over the 

 margin of the cloth diaphragm on to the grains of coke, ^ which will 

 thus be continually bathed by the movement of the liquid, without 

 being inundated, so that the polarization will be suspended, and the 

 bubbles of hydrogen will be freely disengaged through the interstices 

 between the* particles ; besides which, the lower strata of the acidu- 

 lated water, in consequence of the pressure which they have to sup- 

 port, will filter slowly through the cloth, which will not be the case 

 to any extent with the upper and middle strata. Now these lower 



