172 Galvanic Batteries. 
to be used in connexion with the battery before the latter is put into 
action, 3d. The trough is put into readiness for use in an instant, a 
single jug of dilute acid being suflicient for the charge of one hundred 
pairs of four inch plates. 4th. On making the trough pass through 
great and good result; and, upon proceeding to a second experiment, 
the important effect of first contact is again obtained. 6th. The sa- 
ving of zinc is very great. It is not merely that, whilst in action, the 
zine performs more voltaic duty, but all the destruction which takes 
more manageable ; and also that the surfaces of the zinc and copper 
plates may be brought much nearer to each other when the battery is 
constructed, an i 
‘important advantage. Sth. Again 
thinner plates will perform the duty of thick ones, rolled zinc may be 
used ; and ave found rolled zine superior to cast zine in action; @ 
superiority which I incline to attribute to its greater purity. 9th. An- 
o 
is proportionate to the diminution of the zine dissolve Oth. The 
cid Iso is more easily exhausted, and is in such small quantity that 
there is never any occasion to return an old charge into use. Such 
utmost facility ; and after the experiments are concluded, the great 
advantage of easily washing the plates is at command. And it ap- 
pears to me, that in place of making, under different circumstances, 
mutual sacrifices of comfort, power, and economy, to obtain a desired 
, all are at once obtained by Dr. Hare’s form of trough. 
“But there are some disadvantages which I have not yet had time 
to overcome, though I trust they will finally be conquered. One is 
the extreme difficulty of making a wooden trough constantly water- 
