]22 



it, which has yet been proposed, defective. These afford an ample 

 field for research ; and it is much to be wished, that it were occu- 

 pied by some person qualified for the task. In the mean time, 

 though prevented by other employments from endeavouring to reap 

 the harvest, I lay before the Academy a few facts, which I have 

 gleaned on the verge of the forbidden ground. They are not of 

 very high importance ; but, in the present state of our knowledge, 

 no addition to it, however trifling, is to be despised. There is, 

 I believe, no instance, where a fluid does not constitute one of the 

 elements of a Voltaic combination. But what part does it act in 

 them ? that of a conductor of electricity, or a non-conductor ? It 

 may seem strange, that so simple a question should remain to be 

 solved ; but I am under the necessity of thinking, that it has not 

 yet been satisfactorily answered. The discoverer of the pile, and 

 many other philosophers, are of the first opinion ; while the latter 

 seems to be held by Davy, and others of as high authority. To 

 judge from the analogy of that modification of electricity, which is 

 excited by friction in a state of high intensity, water and aqueous 

 fluids should be esteemed conductors ; but analogy is not always a 

 safe guide ; and, in this instance, I am inclined to distrust it, and 

 to imagine, that they transmit electricity by a very different pro- 

 cess from that, by which metals conduct it. If a plate of glass 

 be highly charged, the equilibrium of its sides is frequently re- 

 stored by an explosion which fractures it. In this case, the elec- 

 tricity certainly passes through the glass ; but we do not therefore 

 say, that it is a conductor. If two balls, one communicating with 

 the machine, and the other with the earth, be immersed in oil, 

 the result is the same ; but here its fluidity instantly closes the path 

 of the discharge. In fact, when a jar is charged to the utmost, 

 the tendency of the fluid accumulated on its interior to expand 



