Apologies if this is a little off-topic, but it is nevertheless of some interest to EVO researchers..
THE ROYAL SOCIETY.
S ection A .— M ath em atical and P h ysic a l S ciences.
Spontaneous Incandescence of Substances Atomic Hydrogen
By R. W . W ood, For. Mem. E.S.
(Received June 26, 1922.)
In a previous communication* it has been shown that if a very long
vacuum tube of moderate bore, filled with hydrogen at a pressure of \ mm.,
is operated by a direct or alternating high potential current, the secondary
spectrum appears only at the ends of the tube in the vicinity of the electrode
bulbs, the central portion showing the lines of the Balmer series, with a faint
trace only of the secondary spectrum. By this method photographs of the
series down to the twentieth member were obtained. In more recent work
the series has been photographed to the eighteenth line in the third order
spectrum of a 7-inch plane grating with a lens of 20-feet focus, and the wavelengths determined to within a few thousandths of an Angstrom. This work
will be described elsewhere. Practically all of the very peculiar effects
described in the paper referred to above have been explained, and in the
pursuit of some of the more elusive phenomena, some extremely interesting
properties of atomic hydrogen gas have come to light which will be described
briefly in the present paper.
The work developed out of a study of what I referred to in the earlier
paper as “ Infected Spots.” It was frequently observed that Avhite spots
sometimes appeared along the central portion of the tube, which normally is
fiery-purple in colour, and almost invisible through a green colour filter,
these spots showed the secondary spectrum of hydrogen, with the full
intensity exhibited at the ends of the tube, some fifty times as intense as in
adjacent portions of the tube which gave the nearly pure Balmer spectrum.