372 



Mr. Donovan read the first part of a paper " on the sup- 

 posed identity of the agent in the phenomena of ordinary elec- 

 tricity, voltaic electricity, electro-magnetism, magneto-elec- 

 tricity, and thermo-electricity." This part was introductory 

 to the subject of the remaining portions, which will be de- 

 voted to an attempt to prove that the hypothesis at present 

 accredited by philosophers, as adequate to explain the pheno- 

 mena of the electric fluid, under its various aspects, does not 

 accord with well-observed facts. 



Its object was to render it probable that what is called 

 the electric fluid, is not a simple element, as it is generally 

 believed to be, but that it consists of several constituent ele- 

 ments, each exercising a separate function ; and many facts 

 were referred to in support of the opinion. Reasons were 

 assigned for believing that this hypothesis is more consonant 

 with the general analogy of nature, than the supposition that 

 electricity is a homogeneous fluid. References were also given 

 to the opinions of those who coincide in this view. 



After a full consideration of the facts and arguments, Mr. 

 Donovan summed up as his conclusion, that the electric fluid, 

 in the comprehensive sense of the word, including frictional, 

 voltaic, electro-magnetic, magneto-electric, and thermo-elec- 

 tric, does not consist of one homogeneous element, but of 

 several, viz., heat, light, magnetism, electricity proper, che- 

 mical attraction, the physiological agent, and the deflecting 

 agent : that the difference between the various exhibitions of 

 it just mentioned depends on the proportions or energy of the 

 constituent elements, or the influence of the modifications 

 which, under different circumstances, they are capable of ex- 

 erting on each other. This influence is probably of the same 

 character as that which the forces of nature exercise on each 

 other, on the great scale of creation, controlling, antagonizing, 

 and modifying each other's effects, thus producing the diver- 

 sified phenomena of the universe, but rarely acting indepen- 

 dently. 



