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British Association for the Advancement of Science. 117 
concentrated nitric and dilute muriatic acids. This little apparatus 
produced effects of decomposition equal to the most powerful bat- 
teries of the old construction. Dilute nitric acid diminishes the 
energy ; nitro-sulphuric acid acted as an electrolyte much as ni- 
tric acid; it is an excellent conductor, yielding oxygen at the 
anode, and hydrogen at the cathode. Applying this to my bat- 
tery, I found it to succeed admirably, and hence a considerable 
diminution of expense on the side of the zine; and I also found 
salt and water nearly equal to dilute muriatic acid. By using 
flattened parallelopiped-shaped vessels, the concentrated acid is 
much economized and the metals approximated. * * The ration- 
ale of the action of this combination, according to the chemical. _ 
theory of galvanism, appears to be this. In the common zi 
and copper combination, the resulting power is as the affinity 
the anion of the electrolyte for zinc, minus its affinity for copper ; 
in the common constant battery it is as the affinity of the anion for 
zinc, plus that of oxygen for hydrogen, minus that of hydrogen 
for copper. In the combination in question, the resulting power 
is as the affinity of the anion for zinc, plus that of oxygen for 
hydrogen, minus that of oxygen for azote. Nitric acid being 
much more readily decomposed than sulphate of copper, resistance 
_ is lessened and the power increased ; and no hydrogen being evol- 
ved from the negative metal, there is no precipitation upon it, and 
consequently no counter-action. Ineed scarcely add a word as 
to the importance of improvements of this description in the vol- 
taic battery. This valuable instrument of chemical research is 
thus made portable, and by increased power in diminished space, 
its adaptation to mechanical, especially to locomotive purposes, 
becomes more feasible. 
Prof. Graham remarked on the theory of the Voltaic Cirele. He 
first explained the received views of the propagation of electrical 
induction through the fluid and solid elements of the voltaic cir- 
cle, by the formation of chains of polar molecules, each of which 
has a positive and a negative-side, and in which no circulation 
of the electricities is supposed, but merely their displacement 
and separation from each other in the polar molecule. These 
electricities in the polar molecule of hydrochloric acid, for in- 
stance, are displaced, when the acid acts as an exciting fluid, and 
the positive electricity located in the chlorine atom, and the nega- 
tive electricity in the hydrogen atom. These electricities are at 
