In conclusion, the author remarks, that induction appears to be
essentially an action of contiguous particles, through the intermediation of which the electric force originating or appearing at a certain place, is propagated to or sustained at a distance, appearing there
as a force of the same kind and exactly equal in amount, but opposite in its direction and tendencies. Induction requires no sensible
thickness in the conductors which may be used to limit its extent,
for an uninsulated leaf of gold may be made very highly positive on one
surface, and as highly negative on the other, without the least interference of the two states, as long as the induction continues. But with
regard to dielectrics, or insulating media, the results are very different; for their thickness has an immediate and important influence
on the degree of induction. As to their quality, though all gases
and vapours are alike, whatever be their state, amongst solid bodies,
and between them and gases, there are differences which prove the
existence of specific inductive capacities
The author also refers to a transverse force with which the direct inductive force is accompanied. The experimental proof of the existence of such a force, in all cases of induction, is, from its bearing on the phænomena of electro-magnetism and magneto-electricity, of the highest importance; and we cannot but look forward with the greatest interest to the promised communication in which these and other phænomena relating to this subject will be reviewed.
January 18, 1838
FRANCIS BAILY, Esq., Vice-President and Treasurer, in the Chair
Bryan Donkin, Esq,; Sir John Jacob Hansler; the Rev. George Henry Sacheverell Johnson, M.A.; and George Richardson Porter, Esq., were severally elected Fellows of the Society
"On the Variation of a Triple Integral." By Richard Abbott, Esq F.R.A.S. Communicated by Benjamin Gompertz, Esq., F.R.S.
In the calculus of variations, the discovery of which has immortalized the name of Lagrange, that illustrious mathematician, by differentiating the function with respect to a new variable which enters into it, reduced the general problem of indeterminate maxima and minima to the solution of an equation depending on the variation of the given integral, whether single or multiple, and whose differential coefficient contains any number of variables, or which even depends on other integrals. The author investigates, in the present memoir, the case in which the given function is a triple integral; its variation being composed of two distinct parts, namely, a triple integral and another part, the determination of which must be sought from the limits of the triple integral
"Explanation of the Phenomena of Intermitting Springs." By
