Electricity of Drops. 353 



pyrocatechin, and hydroquinone. Of these the last was the 

 only one that increased the electrical effect of the drops 

 beyond that due to the water in which it was dissolved, and 

 hydroquinone is the only one of the three which has any 

 tendency to combine with oxygen. 



The difference between the magnitude of the changes pro- 

 duced in the electrical effects when the same substances are 

 dissolved in water and alcohol, shows that the quasi-chemical 

 action which produces the electrification is greatly influenced, 

 if not altogether determined, by the solvent. Thus the small 

 effect produced when phenol is dissolved in alcohol compared 

 with that produced when it is dissolved in water, shows that 

 phenol by itself does not produce much electrical eifect, but 

 that when a small quantity of it is dissolved in water, it is 

 put into a state in which it can exert a chemical action which 

 is accompanied by a vigorous electrical effect. The addition 

 of a small quantity of a salt or acid to the water seems to 

 deprive the water of the power of putting phenol into this 

 state, Thus I made a weak solution of sodium chloride which 

 was electrical neutral, and to this added a small quantity of 

 phenol : the solution remained electrically neutral, the drops 

 giving rise to no electrification. The phenol in this case pro- 

 duced no effect, though the same quantity of phenol, when 

 added to pure distilled water, more than doubled the electric 

 effect due to the water. 



The vigorous electric action of some organic substances is 

 very striking, especially the fact that very dilute solutions 

 produce much larger effects than strong ones : in this they 

 resemble inorganic substances, as strong solutions of all the 

 substances I have tried produce very little electrification. 

 This could be accounted for to some extent by the better 

 electrical conductivity of the strong solutions, because this 

 would make it more difficult for the electricity of opposite 

 sign to that on the drop to escape into the air, as it would 

 more readily get into the surrounding fluid : just as Lenard 

 found that the electrification was diminished when the thick- 

 ness of the layer of water into which the drops fell was 

 increased. We cannot, however, attribute the whole, or even 

 the greater part of the diminution due to strong solutions to 

 this cause, since the diminution produced by increasing the 

 strength of the solution is far greater than the increase in its 

 conductivity. 



The conclusion to which I have been led by the study of 

 those drops is that distilled water is a substance which is far 

 from being chemically saturated and inert, but that, on the 

 contrary, it can by its chemical action set up those chemical 



