208 ELECTRO-CHEMICAL ACTION. 



Let us take one particle of common salt (chloride of 

 sodium) weighing less than a grain, and put it into a 

 hundred thousand grains of distilled water. In a few 

 minutes the salt has diffused itself through the whole of the 

 fluid, and in every drop we can detect chlorine and soda. 

 "We cannot believe that this grain of salt has split itself 

 up into a hundred thousand parts ; we conceive rather 

 that the phenomenon of solution is one of diffusion. 

 One infinitely elastic body has interpenetrated with 

 another. 



Instead of an experiment with a pint of water, let us 

 take our stand on Dover heights, and, with a gigantic 

 battery at our command, place one wire into the ocean 

 on our own shores, and convey the other through the 

 air across the channel, and let its extremity dip into the 

 sea off Calais pier the experiment is a practicable one 

 we have now an electrical circuit of which the British 

 channel forms a part, and the result will be exactly the 

 same as that which we may observe in a watch-glass 

 with a drop of water. 



We cannot suppose that the instantaneous and 

 simultaneous effect which takes place in the water at 

 Calais and at Dover, is due to anything like what we 

 have studied under the name of convection, when 

 considering Heat. 



A thousand balls are placed in a line touching each 

 o hher ; the first ball receives a blow, and the last ball 

 flies off with a force exactly equal to the power applied 

 to the first; none of the intermediate balls being 

 moved. 



We cannot conceive that the particle A excites the 

 particle B next it, and so on through the series between 

 the two shores ; but regarding the channel as one large 

 drop, charged with the electric principle as we know it 

 to be, it is excited by undulation or tremor throughout 

 its width, and we have an equivalent of oxygen thrown 

 off on one side of the line, and an exact equivalent of 



