se force of the current, to the
divergent or transverse force of the lines of inductive action belonging to
static electricity (1658, &c.).

1710. In the further consideration of this subject it appeared to me to be
of the utmost importance to ascertain, if possible, whether this lateral
action which we call magnetism, or sometimes the induction of electrical
currents (26. 1048, &c.), is extended to a distance _by the action of the
intermediate particles_ in analogy with the induction of static
electricity, or the various effects, such as conduction, discharge, &c.,
which are dependent on that induction; or, whether its influence at a
distance is altogether independent of such intermediate particles (1662.).

1711. I arranged two magneto-electric helices with iron cores end to end,
but with an interval of an inch and three quarters between them, in which
interval was placed the end or pole of a bar magnet. It is evident, that on
moving the magnetic pole from one core towards the other, a current would
tend to form in both helices, in the one because of the lowering, and in
the other because of the strengthening of the magnetism induced in the
respective soft iron cores. The helices were connected together, and also
with a galvanometer, so that these two currents should coincide in
direction, and tend by their joint force to deflect the needle of the
instrument. The whole arrangement was so effective and delicate, that
moving the magnetic pole about the eighth of an inch to and fro two or
three times, in periods equal to those required for the vibrations of the
galvanometer needle, was sufficient to cause considerable vibration in the
latter; thus showing readily the consequence of strengthening the influence
of the magnet on the one core and helix, and diminishing it on the other.

1712. Then without disturbing the distances of the magnet and cores, plates
of substances were interposed. Thus calling the two cores A and B, a plate
of shell-lac was introduced between the magnetic pole and A for the time
occupied by the needle in swinging one way; then it was withdrawn for the
time occupied in the return swing; introduced again for another equal
portion of time; withdrawn for another portion, and so on eight or nine
times; but not the least effect was observed on the needle. In other cases
the plate was alternated, i.e. it was introduced between the magnet and A
for one period of time, withdrawn and introduced between the