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 zinc ; 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 zinc 

 and copper combination, the resulting power is as the affinity of 

 the anion of the electrolyte for zinc, mifius 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. I need 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 Circle. 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 



