December 28,1872.] THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
m 
Zinc, dilute sulphuric acid, platinum. 
Do. 
do. 
carbon. 
Do. 
do. 
silver. 
Do. 
do. 
copper. 
Do. 
dilute sulphuric (||)* 
nitric acid, platinum (or Grove s 
form). 
Do. 
do. (||) 
nitric acid, carbon (or Bunsen’s 
form). 
Do. a mixture of dilute sulphuric and chromic acids, and 
carbon, -without a porous cell, as re¬ 
commended by Roscoe and Bunsen. 
Do. dilute sulphuric acid (||) carbon and mixed sulphuric 
and chromic acids. 
I add a little permanganate of potash to the negative, 
and you see the potential raised a little. Now I will 
show you some forms of my own. 
.Zinc, solution of potash (II) carbon packed in a mixture of 
carbon, precipitated sulphur, 
peroxide and of manganese 
with dilute sulphuric acid. 
Zinc, common salt (||) . . . do. do. 
Next what is in most respects, I think, the most con¬ 
venient, and best and cheapest in action (for the power 
produced) of all batteries:— 
Zinc, common salt (||) . . carbon packed in granulated 
carbon, peroxide of manga¬ 
nese, with a mixture of 
sulphuric, nitric, and chro¬ 
mic acids. 
The potential of the first of these then is, as you see, very 
high, much higher than a Grove or a Bunsen, indeed, 
nearly 50 per cent, higher. The second and third also 
-considerably higher; the third is very constant, very 
'enduring, and, from the peculiar chemical action of the 
materials, emits none of those poisonous nitrous fumes 
which have so seriously and permanently injured the 
health of many who have used the Grove or Bunsen bat¬ 
teries. Now we -will try the potential of iron instead of 
zinc; this, you will see, is about three-fourths that of 
zinc, so that four cells of iron will be about equivalent 
•to three of zinc. But as iron is about one-third the 
price of zinc, and is much less liable to be affected by 
:local action, it would seem as if there was great advan¬ 
tage in using iron. But as every pound of iron con¬ 
sumed will take a little more acid and manganese than 
the zinc (that is in the proportions of eight and seven), 
.and the internal resistance of four cells will be more 
than that of three, there is, on the whole, probably not 
much economy in using iron. Here is another battery 
in which no acid is used, and in which the potential is 
as high, or nearly as high, as a Grove, and very con¬ 
stant in its action. It is zinc, solution of salt, (||) car¬ 
bon, and the peroxide of manganese, with a mixed salt 
•of sodium, tin, and mercury. For telegraphic purposes, 
where the use of acid is thought objectionable, I know 
sio better form. 
But instead of zinc or iron, or indeed any metal, we 
may use any oxidizable liquid, and collect the electricity 
derived from its oxidization by means of a carbon plate. 
The cheapest, probably, of all is common salt; you see 
this gives a very fair potential, in fact not very short of 
a Daniell. Again, take sulphate of protoxide of iron, 
a very cheap material, which may be kept in a state of 
protoxide by placing it in pyrites or other sulphide of 
iron, which is a material almost valueless. Cyanide of 
potassium, you will see, gives a good potential; also 
hyposulphite of soda, and sulphide of soda or potash. 
You will observe that the potential of this last is very 
much greater than a Daniell, and approaches that of a 
Grove. Sulphide of calcium—a waste material in many 
places—gives a very good potential. Again, brandy 
and water, sugar and water, milk, flour and water, all of 
which, being oxidized by the oxidizing materials of the 
negative side of the battery, produce a considerable gal¬ 
* The mark (II) is intended to denote a porous diaphragm. 
vanic current. Indeed, with these kind of materials the 
battery plays the same part as the stomach and lungs 
of the animal body, the negative part of the battery 
supplying oxygen to oxidize the food materials of the 
positive part, just as the lungs furnish oxygen for oxi¬ 
dizing the food supplied to the stomach and brought 
into circulation in the blood. You will observe that 
milk and tea are more easily acted on, and give a larger 
potential than brandy and water or flour and water. But 
before I conclude this part of my subject, I ought to show 
you the potential of some other of the common forms 
of battery, namely, the Wollaston, the Smee, and the 
Le Clanche. You will see they are much inferior to 
some of the forms I have shown you, besides having 
other disadvantages which I shall show vou in due 
time. 
Well, let me next show you the internal resistance 
and constancy of some of the common forms of battery. 
In order to show this properly we must, of course, take 
elements of an equal size. This instrument is a gal¬ 
vanometer of very small internal resistance, so that, 
practically, it shows you what is the internal resistance 
of the battery, as that is the main element of resistance. 
Of course the potential also affects the result, so that the 
degrees in this instrument will practically show you the 
combined result of potential and small resistance, where 
a large amount of current with a small resistance is 
required; and the loss of power in a minute (I cannot 
afford time to show you the effect of a longer duration), 
will give you some idea of their constancy. 
Let us just take that modification of the Daniell now 
used in the Post-office and generally for telegraphic use. 
You have seen that it stands low in the scale for poten¬ 
tial ; and you will now see that for small internal resist¬ 
ance it stands very low indeed, but that its constancy 
for one minute at least is perfect. But still the amount 
of electricity produced in a minute is so very small that 
it ought to remain constant, there being so little expen¬ 
diture of force in the time. Now, compare with this 
two forms of battery introduced by myself for telegra¬ 
phic purposes—zinc in salt or dilute acid for positive, and 
carbon placed in granulated carbon and peroxide of man¬ 
ganese with dilute acid for negative. You will see the 
comparatively enormously large quantity of electricity 
which this produces; though in the course of a minute, 
where there is no resistance, it of course partially ex¬ 
hausts itself, the peroxide not being able to furnish 
oxygen rapidly enough for the supply; but, after a short 
interval of rest, it recovers its full potential. On the 
London and North-Western Railway ten of these cells 
were found to work to Manchester equally well with 60 
of the ordinary sulphate of copper batteries; not, of 
course, that the potential is six times as large—indeed, 
it is not more than double—but in damp and wet weather, 
where there is much leakage from the wires, the small 
internal resistance of these batteries enables them to 
supply enough electricity to make up for the leakage, 
whereas the larger internal resistance of the Daniell 
batteries prevents them from supplying in a given 
time more than a comparatively small given quan¬ 
tity, which will not bear much loss from leakage. 
I am glad to say that this form of battery is being fast 
adopted for railway use. Then we try the Wollaston— 
a small potential, a small resistance, and a very rapid 
fall of power; then the Smee—a small resistance, fair 
potential, and, in consequence of the rapid escape 
of hydrogen, considerable constancy. To this battery 
the hydrogen fumes are a great objection. Next try the 
Le Clanche, a fair original potential, moderate resist¬ 
ance, and rapid fall of potential. Next, the form I men¬ 
tioned before as introduced by myself, with a higher po¬ 
tential than the Le Clanche, and much more constant, 
though, like the Le Clanche, used without an acid, and. 
therefore quite as permanent. It is simply a solution ot 
common salt with a combined salt of sodium, tin, and 
mercury in the negative. This combination has the pe- 
