Imjirovements in Science. 125 



Currents passed through this liquid affect the galvanometer 

 equally at all depths. In investigating the passage of cur- 

 rents from the first class of conductors to the second, that 

 is, from metals to liquids, it .is necessary to make use of, 

 2nd, The electro-chemical method. Here the tube is di- 

 vided into two equal compartments, by means of a platinum 

 plate, placed transversely so as to prevent any direct commu- 

 nication between the liquids placed on each side of the plate. 

 Both compartments are filled with a solution of acetate of 

 lead, and the current is passed through them. The metallic 

 diaphragm is observed to be coloured on one of its faces 

 with the electro-positive elements of the solution ; while 

 the other surface receives the lead which covers it with a 

 thin layer of fine powder. The decomposition takes place 

 equally over the whole metallic surface, which demon- 

 strates the uniformity of energy in the current, in every 

 part of the conductor. The same appearance takes place 

 on the negative surface. 



1st. The results obtained for uniform conductors are, that 

 currents possess the same electro-dynamic force equally in 

 all parts of the mass which they traverse, and the same 

 chemical power at each of the particular points, where the 

 current passes from the metal into the liquid, or from the 

 liquid into the metal. 



2nd. In using conductors which were not uniform in all 

 their extent, it was found, that in order to double the che- 

 mical effect, it is not sufficient to employ a current possess- 

 ing a double electro-dynamic force ; it is necessary to use a 

 stronger proportion. 



3rd. In support of the results obtained by De la Rive, 

 Nobili found, that currents undergo great difficulty in pass- 

 ing from a liquid into a metallic conductor, and vice versa. 

 This difficulty is so considerable, that a considerable portion 

 of the currents prefer circulating round the diaphragm 

 rather than penetrating it. 



4th. When we introduce two platinum plates into a liquid, 

 as in common decomposition, we can distinguish in the de- 

 posit, upon its surface, three degrees of thickness, strong 

 on the edges of the plate, moderate on the central parts of 

 the anterior face, and weak on the central parts of the 

 posterior face. We have seen, that where the metallic 



