copper, silver,
brass, wood, glass, ivory, or whalebone; the magnet produces no
sensible effect upon any of the substances. You thence infer a
special property in the case of steel and iron. Multiply your
experiments, However, and you will find that some other substances,
besides iron and steel, are acted upon by your magnet. A rod of the
metal nickel, or of the metal cobalt, from which the blue colour used
by painters is derived, exhibits powers similar to those observed with
the iron and steel.

In studying the character of the force you may, however, confine
yourself to iron and steel, which are always at hand. Make your
experiments with the darning-needle over and over again; operate on
both ends of the needle; try both ends of the magnet. Do not think
the work dull; you are conversing with Nature, and must acquire over
her language a certain grace and mastery, which practice can alone
impart. Let every movement be made with care, and avoid slovenliness,
from the outset. Experiment, as I have said, is the language by which
we address Nature, and through which she sends her replies; in the use
of this language a lack of straightforwardness is as possible, and as
prejudicial, as in the spoken language of the tongue. If, therefore,
you wish to become acquainted with the truth of Nature, you must from
the first resolve to deal with her sincerely.

Now remove your needle from its loop, and draw it from eye to point
along one of the ends of the magnet; resuspend it, and repeat your
former experiment. You now find that each extremity of the magnet
attracts one end of the needle, and repels the other. The simple
attraction observed in the first instance, is now replaced by a _dual_
force. Repeat the experiment till you have thoroughly observed the
ends which attract and those which repel each other.

Withdraw the magnet entirely from the vicinity of your needle, and
leave the latter freely suspended by its fibre. Shelter it as well as
you can from currents of air, and if you have iron buttons on your
coat, or a steel penknife in your pocket, beware of their action. If
you work at night, beware of iron candlesticks, or of brass ones with
iron rods inside. Freed from such disturbances, the needle takes up a
certain determinate position. It sets its length nearly north and
south. Draw it aside and let it go. After several oscillations it
will again come to the same position. If you have obtained your
magn