194 Sir H. Davy on the Relations 



it must act with much greater power, as the chemical changes 

 produced are exactly of the kind which must enhance the 

 primary power of the metals. This deduction (a necessary 

 consequence of the electro-chemical theory) I have proved by 

 direct experiment. A series of 6 arcs, composed oi" zinc and 

 copper and solution of nitre, was connected in the proper 

 order with a voltaic arrangement of 50 pairs, and suifered to 

 remain in connexion for 10 minutes; they were then sepa- 

 rated, 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 alkah, and the phitcs 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 antagonist 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 de- 

 struction of the electrical equilibrium is produced by the con- 

 tact of metals or fluids, it is always restored by chemical 

 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 regarded as 

 an electrical circle. 



VIII. General observaiioiis and practical applications. 



To explain the manner in which different chemical agents 

 in combination, and in a perfectly neutral state, instantly start 

 into an active existence, when exposed to the two electrical 

 poles, it is necessary to assume principles, and take views of 

 corpuscular action of a perfectly novel kind ; and as the chief 

 agents are invisible, and probably imponderable, no direct 

 demonstrative evidence can be brought forward on the sub- 

 ject; and different hypotheses may in consequence be applied 

 to it. In assuming the idea of two ethereal, subtile, elastic 

 fluids, attractive of the particles of each other, and repulsive 

 as to their own particles, capable of combining in different 

 proportions with bodies, and according to their proportions 

 giving them their specific qualities and rendering them equi- 

 valent 



