San Marcos free press. [volume] (San Marcos, Tex.) 1877-1892, 1889-05-30
PHOSPHORESCENCE.
THE LIGHT WHICH illuMlNES WITH
OUT CREATING HEAT.

The Glowing Inhabitants Of the Sen-The
Fatal CLEAN Of nfAckerei-The Fireflies
Of South America and tho Lightning
bug" Of the Northern Section.
There Is no subject which tho re-
of scientists have moro COM
pletely failed to elucidate than that OF
the cause Of animal, mineral and vege-
table phosphorescenoe- light which,
unlike all other lights, illumlnes with
out either consuming or giving out any
perceptble heat Tho ocean Is the great
of phosphorescent light On
its surface myriads Of noctiluc~ Qittlo
creatures just visible to the naked eye)
are often seen lighting the waves for
miles, and presenting wonderful effects
when the water is broken by tho bow OF
a ship or tho oars Of boat. Persons who
have passed through q stretch Of water
crowded with noctilucn say that the
light they give dims that OF tho stars,
and makes tho sea look as though 1t were
q vast heaving mass Of metal at white
heat.
Tho Intensity Of the light Is explained
by tho immense quantity Of the little
animals, which ore computed to number
thirty thousand or 30 to the cubic foot.
Bathers In waters where they abound
have often been amazed to find, on
emerging. that their bodies are rendered
luminous by the noctiluc~ that cling to
them.
A kind Of sea slug that Is met with In
the Mediterranean and the Paciflc emits
light from certain spots In the body. 1t
is capable Of being kept in an aquarium,
and there are usually some specimens In
the famous one at Naples. When dis
turbed or swimming tho light makes 1t
look like q flame In the water.
PYRosoMlE.
The most splendid Of tho many lumi-
nous inhabitants Of the sen are tho pyro-
somm At night they look rs though
made Of glowing white hot Iron; diffus-
ing so strong a light that other fishes are
rendered visible when they happen to
swim within thesphere OF their radiance.
A distinguishing feature Of tho pyro-
soma is the variety Of ttnts that It gives
forth-orange, green, azure, blue, white,
and various shades Of dark red having
been all noticed by various observers.
A tiny kind of shark that Is met with oil
the shores Of the southern states OF
America Is noted light giver. Speci-
mems captured and taken into dark
apartment present an extraordinary spec
tacL. The entire surface Of tho head
and body emits n greenish CLEAN that Is
constant, and Is not, as In tho case OF
most Of these luminous inhabitants OF
the sea, increased by friction and agita-
ton.
The smallncss Of the fins Of this fish
show that It Is not an active swimner,
and the assumption ID that its light is
useful In attracting It's prey, on tho prin-
ciplc Of tho torches used by many saw
ages in fishing. Several kinds Of crabs
are luminous. One named the esapphirina
is noted for tho intensely vivid character
Of the light that proceeds from 1t. 30
brilliant Is II that 1t does not need dark
ness to make its presence known, but
corruscates blue, purple. green. gold and
sapphire rnys In full daylight. The
presence Of school Of mackerel Is often
indicated by tho phosphorescent CLEAN
which these fish produce. Fishermen
often descry them at a great distance by
this light, and hasten to surround them
by their nets. It Is thought that mack
erel mako n secretion which gives tho
light, as after they are captured O glcam-
ing fluid Ia noticed running of their
bodies, and sometimes covering the hands
of the mea who toss them from the boat
YrREFiIEs.
It has been urged that the poet was
guilty OF an exaggeration In describing
the frefiies as giving sufficient light to
be of any service; but the accounts OF
travellers In South America, who tell US
that tho natives light their path while
journeying by a couple Of these insects
tied TO their feet, show that he was
speaking quite within the bounds OF pos
sibility. At evening entertainments In
that part Of tho world Il Is customary
far Indies to decorate their hair and
dresses with fireflies, confined by deli
cate silken threads.
The natives Of Vera Cruz do quite q
large trade In flrehies, which they catch
by waving blazing coal at the end OF q
stick Tho insects fiy toward the light,
and are captured In meta Tho firehies
Of Northern America differ from those
just described In the fact that they emit
their light In capricious flashes. instead
Of with a steady. uniform glow. This
peculiarity has gained for them the name
Of lightning bugs" Their light is very
similar TO that Of our giowworm- A
story b told Of some French peasants
who we're returning homo one night and
saw a meteor fall through the sky In
front Of them: about half q mile further
On they came 10 n glowing mass In q
ditch and rushed away terrified, declar-
Ing that a star had fallen upon the earth
and was burning Il up. On investigation
Il was found that this burning star VA
pothinz more uncanny than q mas Of
frog egrs that bad developed phoSphOr'
escence.
Several varieties of the vegetable king.
dom are luminous m . greater o. les'
degree. One q the fungi. which b Dot
Al al uncommon On the walls q damp,
DARK mines, caverns. etc. occasi0uaAly
s-nifs sufscient light 70 admit of the
rsadiug of ordinary print ~ T. Ibs
eruis.son q Hshf from the comma 70
TAO ulhen IN a slsi4 q decoDDositioa /