ffects I have shown--sparks in
unsuspected places and other things--have been observed before. Henry
observed things of the kind and Edison noticed some curious phenomena,
and said it was not electricity but 'etheric force' that caused these
sparks; and the matter was rather pooh-poohed. It was a small part of
THIS VERY THING; only the time was not ripe; theoretical knowledge was
not ready for it." Again in his "Signalling without Wires," in giving
the history of the coherer principle, Lodge remarks: "Sparks identical
in all respects with those discovered by Hertz had been seen in recent
times both by Edison and by Sylvanus Thompson, being styled 'etheric
force' by the former; but their theoretic significance had not been
perceived, and they were somewhat sceptically regarded." During the same
discussion in London, in 1889, Sir William Thomson (Lord Kelvin), after
citing some experiments by Faraday with his insulated cage at the Royal
Institution, said: "His (Faraday's) attention was not directed to look
for Hertz sparks, or probably he might have found them in the interior.
Edison seems to have noticed something of the kind in what he called
'etheric force.' His name 'etheric' may thirteen years ago have seemed
to many people absurd. But now we are all beginning to call these
inductive phenomena 'etheric.'" With which testimony from the great
Kelvin as to his priority in determining the vital fact, and with the
evidence that as early as 1875 he built apparatus that demonstrated the
fact, Edison is probably quite content.

It should perhaps be noted at this point that a curious effect observed
at the laboratory was shown in connection with Edison lamps at the
Philadelphia Exhibition of 1884. It became known in scientific parlance
as the "Edison effect," showing a curious current condition or discharge
in the vacuum of the bulb. It has since been employed by Fleming in
England and De Forest in this country, and others, as the basis for
wireless-telegraph apparatus. It is in reality a minute rectifier of
alternating current, and analogous to those which have since been made
on a large scale.

When Roentgen came forward with his discovery of the new "X"-ray in
1895, Edison was ready for it, and took up experimentation with it on
a large scale; some of his work being recorded in an article in the
Century Magazine of May, 1896, where a great deal of data may be found.
Edison says with regard to this work: "When the X-ray ca