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RECENT PROGRESS IN PHYSICS- 



and also fhat in these solutions the chloride of the metal only is electro^ 

 lized and not the water, for chlorine was always evolved at the posi- 

 tive pole and not oxygen, as would have been the case if the water, 

 even in part only, had been electrolized. 



The solution to be examined was contained in two vessels connected 

 by a syphon, each of which received an electrode. The negative 

 electrode was usually of platinum, while for the positive electrode 

 either this or other metals were used. 



If the solution was liable to be decomposed by the air it was covered 

 with a bell-glass, which could either be exhausted or filled with an 

 indifferent gas. 



Besides this decomposition apparatus a voltameter was inserted into 

 the circuit; the battery usually consisted of 30 feebly charged elements. 



The following table gives the results of a series of experiments : 



The 3d column gives the quantity of water decomposed in the vol- 

 tameter ; the 4th_, that of the metal which should have been pre- 

 cipitated at the negative electrode if for every equivalent of water 

 decomposed 1 equivalent of metal were deposited ; the 5th column 

 shows the quantity actually precipitated. 



In the first three cases 1 equivalent of metal, in fact, was precipi- 

 tated at the negative pole of the decomposing apparatus for 1 equiva- 

 lent of water decomposed in the voltameter ; but in all these cases 

 the electrolized chlorides consisted of 1 equivalent of metal and one 

 of chlorine. 



The chloride of copper contains 2 equivalents of metal to one of 

 chlorine, and in this case for one equivalent of water decomposed in 

 the voltameter 2 equivalents of copper were precipitated in the decom- 

 posing apparatus. 



From the chloride of antimony only -| equivalent of antimony were 

 obtained, and, in fact, it is a combination of only f equivalent of metal 

 for 1 equivalent of chlorine. 



By computing the quantity of chlorine carried to the positive pole 

 of the decomposing apparatus, it appears that for each equivalent of 

 water decomposed there was one equivalent of chlorine evolved. 



This law was also confirmed by another series of experiments, in 



