118 
MR. DANIELL ON VOLTAIC COMBINATIONS. 
in connexion at fig. 2.: {ab c d) is a cylinder of copper six inches high and three 
and a half inches wide ; it is open at the top ( a b) but closed at the bottom, ex- 
cept a collar ( e f ) one and a half inch wide, intended for the reception of a cork into 
which a glass siphon-tube ( ghij k) is fitted. On the top ( a b) a copper collar corre- 
sponding with the one at the bottom rests by two horizontal arms. Previously to the 
fixing of the cork siphon-tube in its place, a membranous tube formed of a part of 
the gullet of an ox is drawn through the lower collar (ef) and fastened with twine to 
the upper (/ m no ) ; and when tightly fixed by the cork below, forming an internal 
cavity to the cell communicating with the siphon-tube in such a way as that when 
filled with any liquid to the level (m o) any addition causes it to flow out at the 
aperture (k). In this state, for any number of drops allowed to fall into the top of 
the cavity, an equal number are discharged from the bottom. ( p q) is a rod of cast 
zinc amalgamated with mercury, six inches long and half an inch diameter, supported 
on the rim of the upper collar by a stick of wood (rs) passing through a hole drilled 
in its upper extremity : (t) is a small cup for the reception of mercury, by which, and 
the cavity (a) at the top of the zinc rod, various connexions of the copper and zinc of 
the different cells may be made by means of wires proceeding from one to the other. 
In fig. 2. the ten cells are represented as connected in single series, the zinc of one 
with the copper of the next. They stand upon a small table in a circle with the 
apertures of the siphon-tubes turned inwards, surrounding a large funnel communi- 
cating with the basin underneath for the reception of any liquid which may overflow. 
A smaller funnel is supported over the internal cavity of each cell by a ring sliding 
upon rods of brass placed between each pair of cells. One of these only is shown in 
the drawing to avoid the crowding of the sketch. 
In the construction of this battery, I have availed myself of the power of reducing 
the surface of the generating plates to a minimum , the effective surface of one of the 
amalgamated zinc rods being less than ten square inches, whilst the internal surface 
of the copper cylinder to which it is opposed is nearly 72 square inches. My principal 
objects have been, to remove out of the circuit the oxide of zinc, which has been 
proved to be so injurious to the action of the common battery, as fast as its solution 
is formed, and to absorb the hydrogen evolved upon the copper without the precipi- 
tation of any substance which might deteriorate the latter. 
The first is completely effected by the suspension of the rod in the interior mem- 
branous cell, into which fresh acidulated water is allowed slowly to drop from the 
funnel suspended over it, and the aperture of which is adjusted for the purpose ; 
whilst the heavier solution of the oxide is withdrawn from the bottom at an equal 
rate by the siphon-tube. When both the exterior and interior cavities of the cell 
were charged with the same diluted acid, and connexion made between the zinc and 
the copper by means of a fine platinum wire -j-^th of an inch in diameter, I found 
that the wire became red hot, and that the wet membrane presented no obstruction 
to the passage of the current. 
