1824.] Conductors when transmitting the Electric Current. 276 



bubble disengaged. Now touch it under the liquid with a clean 

 metallic wire of any kind (provided its extremity be not allayed 

 with sodium), and a violent action instantly commences. 

 The mercury rushes on all sides to the wire in a superficial 

 current as if to give out its sodium, while a copious stream of 

 hydrogen is given off from the wire, not merely at the point of 

 contact with the mercury, but wherever it touches the liquid. 

 In a word, the sodium, the wire, and the liquid, form a voltaic 

 combination, and the electricity produced by the contact is 

 sufficiently powerful to decompose the aqueous portion of the 

 latter in great abundance. The action lasts for a longer or 

 shorter time accordingly as the mercury is more or less highly 

 charged with the alkaline metal, rarely, however, for more than 

 10 or 12 seconds, and, when over, the mercury is found to have 

 lost its positive property, and to be reduced to its pristine state 

 (provided the contact be made with copper or platina), which a 

 long immersion in the fluid without such contact would not have 

 entirely effected. 



26. If the mercury thus charged with the alkaline base be 

 not entirely covered with the fluid, and the metallic contact be 

 made at the vertex of the globule, out of the liquid, no effect is 

 produced ; but if the other end of the metallic wire be bent 

 round and brought to touch the liquid at some distance from the 

 mercury, the violent action above described immediately com- 

 mences ; with this difference, that noiv the surface of the mer- 

 cury is radiated in all directions from the point of contact to the 

 circumference of the globule, and that the whole of the hydrogen 

 is given off at the other end of the wire where it touches the 

 liquid. A little consideration will suffice, however, to show 

 that both thesd effects are merely modifications of one and the 

 same. It is not to, or from the wire as such, that the superficial 

 particles radiate ; they merely follow the direction of the predo- 

 minant electric currents in their passage through the liquid. It 

 is in fact the case of the source of positive electricity, being the 

 mercury itself, instead of its being conveyed to it from a pile at 

 a distance. 



27. Having thus distinctly traced the alteration in the mecha- 

 nical effect by contact with the negative pole, to the amalgama- 

 tion of the mercury with sodium, the knowledge of this fact led 

 me to investigate more minutely the effects of different metals 

 in their contact and amalgamation with mercury; and the results 

 I have encountered in the course of these inquiries, appear to 

 me so remarkable, that I cannot forbear annexing them, espe- 

 cially as they afford an explanation of almost every anomaly 

 which perplexed me in the commencement of the investigation. 

 In oider to render the effects less liable to objection, as well as 

 more distinct and striking, I now used solutions of potash or 



r 2 



