
TRANSACTIONS OF THE SECTIONS. 45 
Ld 
peice of fluorine in the above plants, and he is confident that other chemists, fol- 
owing the same direction, will find it in other plants in which it is likely to occur. 
On a Form of Galvanic Battery. By W.H. Wareny. 
The present form of battery has been the result of an attempt to combine the prin- 
ciples of the batteries now in use, and to avoid some of their present inconveniences. 
Its metallic elements are,—highly carbonized cast iron as a negative plate, and 
‘zine, prepared in a way to be described afterwards, as a positive plate. 
The solution is formed by dissolving some of the cast-iron plates, intended to form 
the negative plates, in one part by measure of oil cf vitriol to eight of water, and 
when there is no free acid in the liquor, adding one-eighth of oil of vitriol. 
In the last battery made (one of 6-inch square plates) the zinc plates were prepared 
by dipping them in dilute sulphuric acid, to cleanse them, washing them well in water, 
then dipping them in a solution of acetate of lead, and drying the laminal deposit 
thus obtained over a charcoal fire; mercury, with a little dilute sulphuric acid being 
then rubbed over the plate, unites with the lead, and this amalgam with the zinc ; the 
excess of mercury is then driven off by second heating over a charcoal fire, and the 
plate is prepared. 
In the form which I have employed, the plates are fixed in a skeleton frame of 
wood, one-sixteenth of an inch apart, alternately iron and zinc, with glass plates be- 
tween every metallically connected pair; the frame with its plates is then placed 
in a trough (of glass in this instance) containing the solution as made above. 
The quantity of electricity passing has been tested with two separate galvano- 
meters, and found to be half that evolved from a Maynocth battery, with plates of 
the same area, in a given time: this experiment has been repeatedly tried when the 
battery has been just put to work, and when it has been at werk with a galvanometer 
in the circuit a whole day. j 
One galvanometer was not very delicate, either in the mounting of the needle or 
the thinness and number of convolutions of its wire, being designed rather for the 
measure of large quantities of electricity, than to test the existence of a small 
amount. 
The other was extremely delicate in the mounting of the needle, and therefore 
could be depended on for its registrations; the current from a single cell battery, 
having a positive plate of 16 square inches active surface, and two negative plates of 
the same active surface each, passing through a wire one-sixteenth of an inch dia- 
meter, and 13 inch from the needle, immediately beneath it, deflected the needle 
more than 30°. 
__In estimating the quantity of electricity evolved from different batteries, Barlow’s 
theorem was used; viz. that the quantity of electricity passing through a given gal- 
vanometer is directly proportional to the tangent of the angle of deflection. 
It was observed, in testing the above single cell battery, that in every instance 
when the battery contact was broken, a small bright spark was visible in daylight. 
It has been remarked that the longer the same solution has been used in an active 
battery, the longer will the addition of a given quantity of sulphuric acid keep the 
flowing current of electricity constant ; also that the battery is much more energetic 
if it be left out of action, for a time equal to that during which it has been in ac- 
tion, immersed in water; it is also necessary that a considerable volume of solution 
should surround the plates. 
This battery is clearly a combination of the principles of the batteries known as 
Daniell’s, Smee’s, Van Melsen’s, Chevalier Bunsen’s, Sturgeon’s, the Maynooth, 
SchGnbein’s Inactive and Active Wrought Iron Batteries, and Robert’s. 
The following advantages peculiar to these.batteries, follow from what has been 
said above :— 
1. Great strength of current both in intensity and quantity. 
2. Constancy of action. 
3. Protosulphate of iron in pure crystals, and pure carbon in fine powder as a sale- 
able residuum, also a sulphate of zinc. 
4. Very great reduction in the current expense of batteries as well as their first 
cost, porous tubes not being used. 
