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VIII. On the Electrical phenomena exhibited in vacuo. By Sir 
Humphry Davy, Bart . P. R. S. 
Read December 20, 1821. 
The production of heat and light by electrical discharges : 
the manner in which chemical attractions are produced, de- 
stroyed, or modified by changes in the electrical states of 
bodies : and the late important discovery of the connection of 
magnetism with electricity, have opened an extensive field of 
enquiry in physical science, and have rendered investigations 
concerning the nature of electricity and the laws by which 
it is governed, and the properties that it communicates to 
bodies, much more interesting than at any former period of 
the history of philosophy. 
Is electricity a subtile elastic fluid ? or are electrical effects 
merely the exhibition of the attractive powers of the particles 
of bodies ? Are heat and light elements of electricity, or 
merely the effects of its action ? Is magnetism identical with 
electricity, or an independent agent, put into motion or acti- 
vity by electricity ? — Queries of this kind might be consider- 
ably multiplied, and stated in more precise and various 
forms: the solution of them, it must be allowed, is of the 
highest importance ; and though some persons have under- 
taken to answer them in the most positive manner, yet there 
are, I believe, few sagacious reasoners, who think that our 
present data are sufficient to enable us to decide on such very 
abstruse and difficult parts of corpuscular philosophy. 
