288 



Mr. Grove on a 7ie'w Voltaic Battery, and 



I underrated very considerably the power of the battery, which 

 with proper arrangements liberates 6 cubic inches of mixed 

 gases per minute, heats to a bright red 7 inches of platinum 

 wire -f-Q^\h of an inch diameter, burns with beautiful scintilla- 

 tions steel needles of a similar diameter, and affects propor- 

 tionally the magnet. The battery consists of four pairs of 

 zinc and platinum foil plates, each metal exposing a surface 

 of fourteen square inches ; the whole occupies less space than a 

 cube of 4 inches in the side. I will now describe the mode in 

 which similar ones may be constructed, which will only differ 

 from this in utilizing both sides of the zinc, and of which the 

 accompanying diagram is a vertical section : A, B, C, D, is a 

 trough of stone ware or glass, with partitions E, E, E, dividing it 

 into four acid proof cells. * The dotted lines (I have omitted 

 letters to prevent crowding the figure) represent four porous 

 vessels of a parallelopiped shape, so much narrower than the 

 cells as to allow the liquid which they contain to be double 

 the volume of that which surrounds them ; the four dark cen- 

 tral lines represent the zinc plates, and the fine lines which 



curve under the porous vessels the sheets of platinum foil, 

 which are fixed to the zinc by little clamp screws. The zinc 

 which I generally employ is the common rolled zinc, of about 



* Dr. Hare showed that in the common battery insulating partitions 

 could be dispensed with. 1 have constructed a constant battery of zinc and 

 copper on the same principle j it is inapplicable to that described in the 

 text, as in it each pair is able to decompose water. 



As in many districts it may be difficult to obtain a trough of stone-ware, 

 I ought to state that my present one is of wood well lined with cement; 

 the only difference from that above described is that the porous vessels are 

 of less width, so as to contain half as much liquid as the spaces around them, 

 and the position of the metals reversed, the platina being placed within 

 the porous vessels and the zinc without. 



