76 Mr Kemp on a New Kind of Galvanic Trotigh. 



of the higher plates of glass from the amalgam of zinc and mercury in the se- 

 cond, and that again from the third by one of the lower plates of glass ; and, 

 ill like manner, throughout the series. Arcs of copper wire c c^c c pass 

 over the higher glass-plates, and dip on the one side into the mercury, and on 

 the other into the amalgam of zinc and mercury ; this serves to connect each 

 pair of plates in the battery. If muriatic acid and water be now poured over 

 the surface of both the amalgam and pure mercury, until it rises nearly to the 

 top of the higher glass -plates or partitions, we shall have a complete commu- 

 nication established throughout the whole series of plates in the battery. The 

 first and second by the arcs of wire, the second and third by the acid and wa- 

 ter, and, in like manner, throughout the whole of them. 



In this arrangement, the mercury and zinc become the positive plate, and 

 the pure mercury the negative one. Troughs of this description may be con- 

 nected with each other in the same way as is done with the ordinary galvanic 

 troughs. 



If the circuit be completed by more or less perfect conductors, the usual 

 galvanic phenomena will be presented. The power of an arrangement of this 

 kind is, however, inferior to that of the cups formerly described, or even to the 

 common trough, with plates of the. same size. This may depend on the dis- 

 tance of the plates of pure mercury from those of the mercury and zinc ; as, 

 from their liquidity, they cannot be directly opposed to each other, either ver- 

 tically or horizontally, as in other constructions where either the positive or 

 negative plate is solid. The transmitting power of a liquid battery of this 

 kind is also very different from those of the ordinary construction. If it be 

 connected with a battery composed of large plates, it transmits, without dimi- 

 nution, the full effect of it ; the only difference observable being a greater 

 evolution of hydrogen. This transmitting power seems to depend upon the 

 liquidity of the plates, as a more rapid motion takes place among the particles 

 of zinc in amalgamation with the mercury in the positive plate ; and probably 

 the oxidation of an equal number of particles takes place in the positive plates 

 of both batteries in a given time, the one by its liquidity, the other by its sur- 

 fece presenting an equal number of points to the action of the acid. 



In this arrangement, no oxide is formed on the surface of the metals ; for, 

 whenever the particles of zinc become oxidated, they are that instant dissolved 

 and taken up by the acid. The action would consequently be of long dura- 

 tion, were it not that, by this process, the acid itself becomes charged with 

 the zinc, and the negative plate reviving the metal held in solution, renders 

 it positive, and restores the equilibrium. 



If the little finger of each hand be placed into the extreme cells of a battery 

 of nine plates, such as I have described, the shock will be quite perceptible ; 

 if two are used of the same size, viz. eighteen plates and small platina wires 

 employed to form the circuit, the decomposition of water will be effected ; and 

 if twenty-seven plates are used, the shock will be considerable. 



The electro.magnetic effects of this battery are very weak, which is owing 

 to the arrangement as well as the size of the plates. 



The only other form of galvanic apparatus which I shall at present notice, 

 consists of a wooden trough AB, Fig. 1. Plate III., supported on four pillars, 

 about four inches in height, the same size, and divided in precisely the same 



