rangement marked A B D, the other and far greater
part, as indicated by the arrows. The magnetic needle was then forced back,
by pins applied upon opposite sides of its two extremities, to its natural
position when uninfluenced by a current; after which, contact being
_broken_ at G or E, it was deflected strongly in the opposite direction;
thus showing, in accordance with the chemical effects (1084), that the
extra current followed a course in the cross-wires _contrary_ to that
indicated by the arrow, i. e. contrary to the one produced by the direct
action of the electromotor[A].

[A] It was ascertained experimentally, that if a strong current was
passed through the galvanometer only, and the needle restrained in one
direction as above in its natural position, when the current was
stopped, no vibration of the needle in the opposite direction took
place.

1088. With the _helix_ only (1061.), these effects could scarcely be
observed, in consequence of the smaller inductive force of this
arrangement, the opposed action from induction in the galvanometer wire
itself, the mechanical condition and tension of the needle from the effect
of blocking (1087.) whilst the current due to continuance of contact was
passing round it; and because of other causes. With the _extended wire_
(1064.) all these circumstances had still greater influence, and therefore
allowed less chance of success.

1089. These experiments, establishing as they did, by the quantity,
intensity, and even direction, a distinction between the primary or
generating current and the extra current, led me to conclude that the
latter was identical with the induced current described (6. 26. 74.) in the
First Series of these Researches; and this opinion I was soon able to bring
to proof, and at the same times obtained not the partial (1078.) but entire
separation of one current from the other.

1090. The double helix (1053.) was arranged so that it should form the
connecting wire between the plates of the electromotor, in being out of the
current, and its ends unconnected. In this condition it acted very well,
and gave a good spark at the time and place of disjunction. The opposite
ends of ii were then connected together so as to form an endless wire, i
remaining unchanged: but now _no spark_, or one scarcely sensible, could be
obtained from the latter at the place of disjunction. Then, again, the ends
of ii were held so nearly together that any current run