414 Sir Humphry Davy on the relations of 
proved by direct experiment. A series of 6 arcs, composed 
of zinc and copper and solution of nitre, was connected in 
the proper order with a Voltaic arrangement of 50 pairs, 
and suffered to remain in connexion for 10 minutes; they 
were then separated, and made to act as a single battery : 
their powers were extremely feeble, not certainly one-third 
as great as those of a combination of the same kind which 
had been in action (but unconnected) for the same time. 
Six arcs of copper and zinc were now connected with the 
same battery of 50, in a reverse or unconformable manner, 
so that the six plates of zinc gave off hydrogen and attracted 
alkali, and the plates of copper oxidated and attracted acid. 
Being separated after a few minutes, and made to act alone, 
they exhibited powers which appeared three or four times 
greater than if they had never been in connexion ; the zinc 
resumed a much higher positive, and the copper a higher 
negative state, than if they had not before been in the anta- 
gonist or unconformable conditions. 
All these facts bear upon the same point, and confirm the 
view which I took of the nature of Voltaic combinations in 
the Bakerian Lecture for 1806; in all of which, whether 
the destruction of the electrical equilibrium is produced by 
the contact of metals or fluids, it is always restored by che- 
mical changes, and in which the circulation, if it may be so 
called, depends upon a union of these causes, the direction of 
the currents being always opposite in the metallic and fluid 
parts of the combination, so as to produce what may be re- 
garded as an electrical circle. 
