ly6 Sir H. Davy on the Relations 



III this way, the two electricities may be regaided as the 

 transporters of the ponderable matters, which assume their 

 own peculiar characters at the moment they arrive at the point 

 of rest. I shall detail an experiment which I made imder a dif- 

 ferent form some years ago, and which may assist the imagina- 

 tion in the conception of this singular and mysterious mode 

 of action. A flat glass basin, 10 inches in diametei', was filled 

 with water containing l-2000ndth pnrt of its weight of sul- 

 phate of potassa, in the bottom of which ao or 40 separate 

 globules of mercury, containing from 10 to 100 grains each, 

 were placed without any regaid to order ; two wires of pla- 

 tinum from a battery of 1000 double plates, weakly charged, 

 were made to connect the extremities of the water (passing to 

 the bottom of the basin). As soon as the electrical commu- 

 nication was made, the globules of mercury in or near the 

 current became instantly agitated ; their negative poles be- 

 c.mie elongated, and approached either the positive pole of 

 the battery, or the positive pole of the contiguous globules of 

 mercury, and streams of oxide flowed with great rapidity from 

 the positive toward the negative pole. No hydrogen appeared 

 at the negative poles of the globules of mercury ; but after the 

 action had continued a few minutes, and was then suspended, 

 there was an appearance of some minute globules, owing, as 

 was proved by tests, to the formation and oxidation of potas- 

 sium which had combined with the mercury, and which, as 

 is evident from Mr. Herschel's researches, had given to that 

 part of the globule in which it had combined its high electro- 

 positive qualities. When the connexion was again made, the 

 same series of constant and violent motions took ])lace; the 

 elongated and negative extremities of every globule moving 

 towards the positive surfaces, and undergoing continual oscil- 

 lations; but on pouring a small quantity of muriatic acid into 

 the water, so as to make it slightly acid, these phasnomena 

 ceased ; the masses of mercury resumed their spherical form, 

 hydrogen was given off from the negative surfaces, and all 

 motion and agitation were at an end. The energy of the acid in 

 this case being negative, may be considered as neutralizing the 

 power of the potassium by its immediate contact,, and as de- 

 stroying all the phaenomena of attraction by the positive pole. 



In the numerous experiments that I made in 1806, on the 

 transfer of acids to the positive pole and of alkalies to the 

 negative pole, there were similar instances in which masses of 

 acid or alkaline matters, by exerting their own peculiar ener- 

 gies, prevented the accumulation of the antagonist elements 

 at their points of rest, so as to destroy, or materially weaken, 

 tlieir power of motion or transport. For instance, in attempt- 

 ing 



