been discharged, but only portions of it, more or
less according to circumstances; whereas, whenever the effect has been a
distinct spark throughout the whole of its course, the discharge has been
perfect, provided no interruption had been made to it elsewhere, in the
discharging circuit, than where the spark occurred.

[A] Description of the Teylerian machine, vol. i. pp. 28. 32.; vol.
ii. p. 226, &c.

[B] Philosophical Transactions, 1834, p. 213.

1449. When an electrical brush from an inch to six inches in length or more
is issuing into free air, it has the form given, fig. 117. But if the hand,
a ball, of any knobbed conductor be brought near, the extremities of the
coruscations turn towards it and each other, and the whole assumes various
forms according to circumstances, as in figs. 119, 120, and 121. The
influence of the circumstances in each case is easily traced, and I might
describe it here, but that I should be ashamed to occupy the time of the
Society in things so evident. But how beautifully does the curvature of the
ramifications illustrate the curved form of the lines of inductive force
existing previous to the discharge! for the former are consequences of the
latter, and take their course, in each discharge, where the previous
inductive tension had been raised to the proper degree. They represent
these curves just as well as iron filings represent magnetic curves, the
visible effects in both cases being the consequences of the action of the
forces in _the places where_ the effects appear. The phenomena, therefore,
constitute additional and powerful testimony (1216. 1230.) to that already
given in favour both of induction through dielectrics in curved lines
(1231.), and of the lateral relation of these lines, by an effect
equivalent to a repulsion producing divergence, or, as in the cases
figured, the bulging form.

1450. In reference to the theory of molecular inductive action, I may also
add, the proof deducible from the long brushy ramifying spark which, may be
obtained between a small ball on the positive conductor of an electrical
machine, and a larger one at a distance (1448. 1504.). What a fine
illustration that spark affords of the previous condition of _all_ the
particles of the dielectric between the surfaces of discharge, and how
unlike the appearances are to any which would be deduced from the theory
which assumes inductive action to be action at a distance, in straight
lines only; a