ELECTROLYTIC LAWS. 17 



remarked that an electric current could pass through water, but 

 not through ice, although the composition of the two substances 

 is identical ; he concluded from this that in the liquid state the 

 molecules were allowed to place themselves in the direction of 

 the line of polarisation, whereas the rigidity of the solid state 

 was opposed to such a direction of the molecules taking place. 



ELECTROLYTIC ACTION OF CURRENTS. In all chemical 

 baths which are being electrically treated, the current enters 

 through the anode, travels across the liquid space comprised be- 

 tween the anode and the cathode, and leaves through the cathode. 



It is during the space of time taken by the current to travel 

 between the two electrodes that the action of electrolysis takes 

 place. 



If, in order to fix ideas, we assume that an electric current 

 is passing through a binary compound, liquid and conductive, 

 as, for example, chloride of copper, the current decomposes 

 the chloride into its two constituents ; the chlorine going to the 

 positive pole or anode, and the pure copper depositing itself on 

 the cathode. This decomposition requires a certain expendi- 

 ture of work, which we will analyse further on. 



The metal always goes to the negative, and the other con- 

 stituents to the positive pole. If operating on a sulphate of 

 copper bath, the copper will be deposited on the cathode or 

 negative pole, and both the oxygen and the sulphuric acid will 

 go to the anode or positive pole. There, however, sometimes 

 occur some secondary actions which cause the primordial effect 

 to be disturbed. 



FARADAY'S LAWS. First law: The quantity of substance 

 decomposed in a given time is proportional to the intensity of 

 the current, or, in other words, to the quantity of electricity 

 passing through the liquid. This law may be verified by 

 means of a water voltameter, the discharges of a condenser, or 

 the current of a battery, or of an induction machine being used 

 for the purpose. The quantity of gas generated in each of the 

 tubes of the voltameter for a quantity of electricity equal to 

 two, three, four, &c., fold that of a first experiment will always 

 be corresponding to the quantity of current passed through it. 



A very important fact results from this first law, viz. that in 



c 



