Washington sentinel., 1899-01-07

Of what is known upon the subject
NAV not be out OF place. The first
inquiry naturally suggesting itself
is as to the character of this light
as compared with light from other
sources. It has been found that
the light of glowworms contains
Photographic rays which WILL pass
through aluminium. 1t has also
been found that the rays emitted
bv freflies, after filtration through |
cardboard or through copper |
plates, will act photographically,
and are capable Of reflection and
probably refraction and polariza
ton. This would indicate the
presence Of rays belonging TO the
extreme extra violet end OF the
spectrum, since 1t is known thaI
extreme ultra violet rays have the
power Of passing through bodies
Opaque to the longer wave lengths
visible to the eye. If this is so,
they are probably the same as the
invisible rays emitted by uranium
and its salts, which have the power
OF passing through aluminium ana
cardboard and are capable OF re-
hection, reiraction and polarI|a-
ton. These are known as Sec
ouereIs rays. In short, therefore,
we NAV say that the light OF the
6reAv contains invisible photo
graphic rays from the extreme
| violet end of the spectrum, IN ad'
| drtion to the ordinary light rays.
Turning now to the construction
OF the light-producing apparatus,
il has been found by Max Schultz
that this organ in the glowworm
consists Of a pale, transparent,
superficial layer, which gives DIT
the light, and a deep opaque layer
whose function is less obvious.
The Italian 6reAy, in which both
male and female are luminous,
has been examined by Emery.
| Here, as in the glOwworm, the
organ was found to consist OF two
layers. II has also been iound
that the ultimate branches OF the
tracheR. or air tubes, are distr.-
buted through the photogenlc
| apparatus; nerve hbres are also
present. The luminous organ IN
the FREELY is regaI ded as homolo-
gous to the "fat body often found
| in insects, Now, directing atten-
ton to the cause Of the Light, we
are met by two very sIgnIhcant
discoveries first, that carbonic
acid extinguishes the light; and,
second, that oxygen intensitles It.
These facts, in conjunction with
the known distribution ofair tubes
to the photogenic body, point very
| strongly 70 the theory that the
| light is the result OF some form OF
! slow combustion; while the fatty
nature Of the luminous cells indI-
Gates the probability Of tat, with
some form of free phosphorus, as
the active agent.
II may be added that, as regards
| light producing animals in general,
il has been found in a large num-
! Der Of them that the luminous or
| gaus retain their power after death,
and even alter desIcCatiOn and sub
sequent moistening. There would,
therefore, seem no reason to adopt
the theory that we have here to
deal with any direct transformation
OF vital INTO radient energy. The
most probable explanation of the
phenomena, at least in the FREELY
and GLOW worm, is that it IS the re-
suit Of slow combustion. And yet,
even granting this is the cause oi
the light, there remains still to be
explained why this form Of slow
combustion produces these ex-
treme ultra violet rays, while other
forms OF combustion do not. There
are some underlying mystery oi
molecular physics here well worth
investigation.