to observe, fill pages of every scientific journal that comes to
hand. And before the necessary time elapses for this article to
attain publication in America, it is in all ways probable that the
laboratories and lecture-rooms of the United States will also be
giving full evidence of this contagious arousal of interest over a
discovery so strange that its importance cannot yet be measured,
its utility be even prophesied, or its ultimate effect upon
long-established scientific beliefs be even vaguely foretold.

[Illustration: PICTURE OF AN ALUMINIUM CIGAR-CASE, SHOWING CIGARS
WITHIN.

From a photograph by A.A.C. Swinton, Victoria Street, London.
Exposure, ten minutes.]

[Illustration: PHOTOGRAPH OF A LADY'S HAND SHOWING THE BONES, AND A
RING ON THE THIRD FINGER, WITH FAINT OUTLINES OF THE FLESH.

From a photograph taken by Mr. P. Spies, director of the "Urania,"
Berlin.]

[Illustration: THE PHYSICAL INSTITUTE, UNIVERSITY OF
WÜRZBURG, WHERE PROFESSOR RÖNTGEN HAS HIS RESIDENCE, DELIVERS HIS
LECTURES, AND CONDUCTS HIS EXPERIMENTS.

From a photograph by G. Glock, Würzburg.]

The Röntgen rays are certain invisible rays resembling, in many
respects, rays of light, which are set free when a high pressure
electric current is discharged through a vacuum tube. A vacuum tube