IN INCREASING THE INTENSITY OF ELECTRICITY. 547 
the first polarity ; several alternations of this kind being observed*. 
Now this is precisely what would take place if we suppose that the 
principal current induces a secondary one in an opposite direction in 
the air surrounding the conductor, and this again another in an oppo- 
site direction at a great distance, and so on. ‘The needles at different 
distances would be acted on by the different currents, and thus the 
phenomena described be produced. 
The action of the spiral is also probably connected with the fact in 
common electricity called the lateral discharge: and likewise with an 
appearance discovered some years since by Nobili, of a vivid light, pro- 
duced when a Leyden jar is discharged through a flat spiral. 
The foregoing views are not presumed to be given as exhibiting the 
actual operation of nature in producing the phenomena described, but 
rather as the hypotheses which have served as the basis of my investi- 
gations, and which may further serve as formule from which to deduce 
new consequences to be established or disproved by experiment. 
Many points of this subject are involved in an obscurity which requires 
more precise and extended investigation ; we may, however, confidently 
anticipate much additional light from the promised publication of Mr. 
Faraday’s late researches in this branch o science. 
* Cumming’s Demonferrande, p. 247; also Edinburgh Journal, October 
1826 
NOTE. 
[For an account of some recent investigations relative to the subject of the 
preceding Articles, the reader is referred to “‘ An Inquiry into the Possibility and 
Advantage ofthe Application of Magnetism as a Moving Power: By the Rev. 
James William M‘Gauley, in the Report of the Dublin Meeting of the British 
Association, 1835.” See Phil. Mag. and Annals, vol. vii. p.306. A further 
communication was made by the same gentleman at the Bristol Meeting, 1836, 
| —Ept.] 
Ver. Paar IV ap 
