122 Mr. M. Donovan on the supposed Identity of the Agent 



lamp by melting the glass ; and the whole was immersed in a 

 vessel of water, and kept there for fourteen days. The flask 

 being withdrawn and dried, its neck was cut off. Holding the 

 coating in one hand, and introducing a wire into the mercury 

 with the other, I received a shock, reduced, it is true, from 

 what it had been. It can scarcely be believed that this electri- 

 city consisted in vibrations : it were singular if vibrations could 

 be thus confined in a bottle for fourteen days and still continue. 

 The same experiment was made long afterwards by Faraday ; 

 but the glasses being kept for two or three years, the whole 

 charge escaped. 



Some persons may object to my experiment, that during this 

 period the electricity was quiescent, and that on its liberation 

 the vibrations recommenced. But this implies that there was a 

 something confined which was capable of vibrating : — What was 

 it ? If it was an sethereal fluid, as some say, it may as well be 

 named the electric fluid. 



It is indeed of little consequence to the opinions here advo- 

 cated, whether electricity be considered as matter, or vibrations 

 of some peculiar sether, or of any conceivable state of existence ; 

 it will answer the present purpose to view the electric fluid as a 

 combination of elementary forces or agents of whatever kind. 

 These constituent forces or agents must be maintained in a state 

 of association, coerced by some peculiar attraction or affinity. 

 Whatever the bond of union, there must be some such bond, be 

 its nature or name what it may ; as without the intervention of 

 such a power, the integrity of the compound fluid would be with- 

 out an assignable cause, and no explanation could be given of the 

 passage of all the constituent elements through certain kinds of 

 matter, which under other circumstances would have been imper- 

 vious to some of them. We know that in the constitution of 

 other imponderables such a power exists. The phosphorescence 

 of certain bodies was at one time attributed to chemical attraction 

 mutually subsisting between light and the phosphorescent body, 

 to the consequent absorption of the former, and its extrication 

 in the dark. It is true that the present term used to express 

 this effect is adhesion, which still implies attraction of some kind. 



This attraction or adhesion is generally admitted to maintain 

 the state of combination between other imponderable elements ; 

 such seems to subsist in the sun -beam, the heterogeneous rays 

 of which travel from the sun to the earth 96 millions of miles in 

 a state of integrity : they may be separated, it is true, by various 

 processes ; but without the employment of such they cohere with 

 obstinacy. Mr. Mackintosh has several times observed the sun's 

 rays to be so much concentrated by the convex glasses which 

 answer the purpose of windows in a diving-bell, that the clothes 



