, however, to demonstrate Oersted's
experiments, using small strips of zinc and copper dipped in
ammonium-chloride solution.

Amid innumerable, rambling theorizations (such as, that "hydrogenation
affects magnetism as oxidation affects galvanism," or "sulphur,
phosphorous and carbon are especially significant in magnetism, since
iron in combination with any of these inflammable materials becomes a
magnet-material"), Schweigger announces that he looked for the reactive
force of the needle on the connecting wire in the simple Oersted
experiment, and that he used his "amplifying apparatus" to look for
magnetic effects from an electrostatic machine, but without success in
both cases. He suggests that he will continue with many more
electromagnetic experiments because "with the use of the
doubling-apparatus, the needle, instead of needing for excitation a cell
capable of generating sparks, approaches more closely the sensitivity of
a twitching nerve." However, "additional special experiments are
required to find to what limits the amplification can be increased by
the method I have created in the construction of this
doubling-apparatus, using multiple turns of wire."

[Illustration: Figure 3.--THIS WIRE "BOW-PATTERN" was the first
illustration Schweigger gave of his "doubling apparatus," though he had
presented a verbal description of a single-coil arrangement somewhat
earlier. The purpose of the bow pattern was to show that compass needles
at the centers of the two loops deflected in opposite directions. (From
_Journal fuer Chemie und Physik_.)]

PAPER READ IN HALLE, NOVEMBER 4, 1820

[The first half of this paper describes successful observations of the
reaction-force of a magnetic needle on the connecting wire of a voltaic
circuit, achieved by pivoting the connecting wire in the form of brass
needles above and below the compass needle. Though the multiplier
configuration of needle and wire is in fact present here, Schweigger
does not mention it, evidently regarding this as a separate project. He
continues.]

In my lecture of September 16th, I showed that Oersted's results
depend, not on the voltaic cell, but only on the connecting circuit.
The principle I have used for amplification of the effects, for the
construction of an electromagnetic battery as it were, was the
winding of wire around the compass, and I now present to the Society
a bow-pattern of multiple-wound, wax-insulated