concerned in the Phanumena of ordinary Electricity, b$c. 121 



positive and negative states, the difference of which is at present 

 incomprehensible although remarkable. This opinion has been 

 the source of all the difficulties experienced in the efforts of 

 philosophers to reconcile the differences of effect in the various 

 forms of electricity. By admitting the compound nature of the 

 electric fluid, the occasional variation in its constitution already 

 alluded to, and the consequent existence of combinations of these 

 constituents so different from each other as to constitute distinct 

 agents, we reduce the conflicting phenomena under one com- 

 prehensive explanation, namely, that they are the effects of causes 

 specifically different. 



If it be hypothetical to assume, as I do, the compound nature 

 of the electric fluid, surely it is as much so to suppose with others 

 that it is a simple element. The former is supported by analogy 

 and several undoubted facts j the latter, as will be hereafter 

 shown, leads to contradictions and embarrassments. Besides, 

 the compound nature of electricity is in some sort maintained by 

 all those who conceive the existence of two fluids which by com- 

 bination neutralize each other, and thus constitute the natural 

 state of equilibrium. Perhaps the notion here entertained may 

 suggest the idea that in the excitation of electricity, whether by 

 friction, chemical action, heat or magnetism, the compound fluid 

 is decomposed into the positive and negative states belonging to 

 each variety of electricity, an unequal division of the constituent 

 elements giving rise to the difference of properties which then 

 becomes so remarkable. It is only in this state of decomposition 

 that electricity of any kind is sensible or active. 



The different elementary forces, which are here supposed to 

 constitute the electric fluid, are in some manner embodied into 

 a singular state of existence, neither solid, liquid, nor aeriform ; 

 a something of extreme tenuity ; imponderable, yet possessing 

 some of the characters of materiality. Mr. Sturgeon appears to 

 me to have given the preponderance to the probability of the 

 opinion that electricity is matter, difficult as it may be to com- 

 prehend such a strange constitution: He seems to have been 

 successful also in proving that the idea of vibrations, as applied to 

 electricity, is incomprehensible. An experiment which I made and 

 published (Phil. Mag. S. 1. vol. xliv.) many years since, induces 

 me to consider the doctrine of vibrations less probable than that 

 of the materiality of the electric fluid : it was as follows : — A 

 wire depending from the prime conductor of an electrical machine 

 was made to convey a charge down through the long slender 

 neck of a very thin glass flask, the lower hemisphere of which 

 was externally coated with fin-foil, and filled to the same height 

 with mercury. The flask, now a Lcyden phial, being charged, 

 was withdrawn from the charging wire; its neck was sealed at a 



