ital organs which may be abnormally developed or
degenerate. How much this means to medical and surgical practice it
requires little imagination to conceive. Diagnosis, long a painfully
uncertain science, has received an unexpected and wonderful assistant;
and how greatly the world will benefit thereby, how much pain will be
saved, only the future can determine. In science a new door has been
opened where none was known to exist, and a side-light on phenomena has
appeared, of which the results may prove as penetrating and astonishing
as the Roentgen rays themselves. The most agreeable feature of the
discovery is the opportunity it gives for other hands to help; and the
work of these hands will add many new words to the dictionaries, many
new facts to science, and, in the years long ahead of us, fill many more
volumes than there are paragraphs in this brief and imperfect account.

THE WIRELESS TELEGRAPH

GEORGE ILES

[From "Flame, Electricity and the Camera," copyright by Doubleday,
Page & Co., New York.]

In a series of experiments interesting enough but barren of utility, the
water of a canal, river, or bay has often served as a conductor for the
telegraph. Among the electricians who have thus impressed water into
their service was Professor Morse. In 1842 he sent a few signals across
the channel from Castle Garden, New York, to Governor's Island, a
distance of a mile. With much better results, he sent messages, later in
the same year, from one side of the canal at Washington to the other, a
distance of eighty feet, employing large copper plates at each terminal.
The enormous current required to overcome the resistance of water has
barred this method from practical adoption.

We pass, therefore, to electrical communication as effected by
induction--the influence which one conductor exerts on another through
an intervening insulator. At the outset we shall do well to bear in mind
that magnetic phenomena, which are so closely akin to electrical, are
always inductive. To observe a common example of magnetic induction, we
have only to move a horseshoe magnet in the vicinity of a compass
needle, which will instantly sway about as if blown hither and thither
by a sharp draught of air. This action takes place if a slate, a pane of
glass, or a shingle is interposed between the needle and its perturber.
There is no known insulator for magnetism, and an induction of this kind
exerts itself perceptibly for