Page:Electricity (1912) Kapp.djvu/125

the simplest case of the electrolyte being water, which has been rendered conducting by a slight addition of some chemical, such as sulphuric acid. The two substances out of which water is formed are the gases oxygen and hydrogen. The current, in passing through the water, tears these oxygen and hydrogen atoms asunder and carries them off, the hydrogen in the direction of its own flow, namely, to the kathode, and the oxygen in the opposite direction, that is to say, to the anode. Here the gases are deposited in the form of bubbles, which from time to time become detached and rise to the surface. By using an arrangement such as shown in Fig. 6 the gases may be separately collected and their volume measured. A and K are two platinum wires fused into the bottom of the glass vessel, which is filled with acidulated water. Over these electrodes are placed two inverted glass tubes also filled with water and closed at the top, so that the gases liberated at the electrodes may be collected and their volume measured. It is found that the space filled by hydrogen, H, is exactly twice as great as that filled by oxygen, O; and this is precisely the volumetric proportion in which these two gases form water. The direction