VEGETABLE LAMPS.
One of the most remarkable and awe-inspiring phenomena of the ocean is
the water-spout,--a lofty column composed of tons of water, whirling
upward, lifted by the mighty force of the wind. From a distance the
formation of a spout is an interesting sight. In my own observations,
there has generally been a low-lying bank of dark lead-colored cloud
to announce its coming. From this a sharp cone, seemingly of cloud,
was seen to drop, and in a very few moments an attenuated pillar rose
from the water directly beneath it. The two appeared to meet, and, the
alliance consummated, the lofty column moved away with a greater or
less velocity.
Near proximity to them is not unaccompanied with danger; and I once
found myself in the centre of four or five, which were moving slowly
about. The wind almost entirely died away, so that had our boat been a
large one, we would have been completely at the mercy of the aqueous
giants; as it was, we lowered the sail, and taking the oars, succeeded
in avoiding them all.
It is the general impression, that if a water-spout touches an object,
or is struck, its form is broken, and the water descends; but this is
not always the case. I was standing one day upon the sea-wall of Fort
Jefferson, on the island of Tortugas, Florida reef, when I perceived a
lofty water-spout, a mile to the east, headed directly for the fort,
as I thought. In a few moments it struck Long Key, a narrow island a
quarter of a mile away; passing over perhaps one hundred and fifty
feet of it, striking a small schooner which had been hauled upon the
beach, twisting it around, and then continuing its course with great
rapidity. It now turned a little to the north; and, seeing that in all
probability it would not strike the fort, I awaited its coming. Never
shall I forget the awful grandeur of the sight, as the watery monster,
seemingly several thousand feet in height, reached the shoal. For some
reason which I cannot explain, the central portion was invisible, but
the upper part was distinctly seen, and appeared to be nearly over my
head; and its proximity may be imagined from the fact that the drops
from it seemed like a heavy rain. The entire spout was bent like a bow
by the wind, and was moving along with great rapidity. I could not keep
up with it, though running at utmost speed as it passed. Its progress
was accompanied by a loud roar, and a hissing, splashing sound, while
great masses of foam were thrown up before and behind. In its wake
followed numbers of gulls, feeding upon the small fishes killed by
the rush of waters; and where it crossed the shoal, in perhaps eight
feet of water, quite a trench was scooped out. Imagine such a column
at night coursing over the ocean; its entire shape outlined against
the darkness in phosphorescent light (Plate XXV.), and an idea may be
gained of the magnificent spectacles which, on rare occasions, are
produced by some of the simplest of plants,--the diatoms,[45] whose
nuclei are luminous.
The southern oceans, in certain places, often swarm with these minute
light-givers, and when borne aloft in the spout, they tend to produce
one of the most remarkable and striking scenes possible to imagine. In
color these luminous columns are yellow, of different shades, according
to the numbers of diatoms present. The naturalists of the “Challenger”
found that _P. pseudo-noctiluca_ was always present, and often
existed at the surface in vast numbers, in the tropics and subtropical
regions where the temperature was over sixty-eight or seventy degrees;
and the most beautiful exhibitions seen during the cruise were due to
these little forms. They have been observed in the Bay of Funchal all
the year round. The light was equally brilliant in each species; and in
each, when disturbed several times in succession, the phosphorescence
perceptibly diminished, and finally disappeared: but after an hour’s
rest, it re-appeared as brilliant as before.
The phosphorescence of plants, though not so remarkable in its general
manifestations as in the forms previously reviewed, is sufficiently
interesting to attract general attention. In nearly all countries these
vegetable lamps are found; and even in the old legends of the Greeks,
Hindus, and Persians, references to the “burning bush,” and other
luminous phenomena are met with, evidently having some foundation in
fact. In India the old natives tell the story, that their forefathers,
who visited the mountain of Sufed Koh, at the north of Nalroo in
Afghanistan, found a spring in which grew a bush which, from a
distance, seemed to emit a brilliant light; but if any one approached,
it immediately disappeared, vanishing in the air. In 1845 the white
residents of Simla were informed by the natives that a wonderful plant
was illuminating the mountains near Syree; and those who investigated
it expressed the belief that the light, if it existed at all, came from
a species of _Dictamnus_, which was known to grow about Gungotree
and Jumnotree.
Even in Josephus we find reference to the luminosity of plants. “There
is a certain place,” he says, “called Baaras, which produces a root
of the same name with itself; its color is like to that of flame, and
towards evening it sends out a certain ray like lightning; it is not
easily taken by such as would do it, but recedes from their hands.”
In the “Proceedings of the Royal Asiatic Society” of April, 1845, there
is reference to a luminous root-stock found in the Oraghum jungles,
“gleaming in the dark with all the vividness of a glow-worm, or the
electric scolopendra, after having been moistened with a wet cloth
applied to its surface for an hour or two, and did not seem to lose
the property by use, becoming lustreless when dry, and lighting up
again whenever moistened.” It is probable that this is the plant which
is referred to by the Brahmins as _Jyotismati_, produced, it is
said, by a variety of _Cardiospermum_. According to Sanscrit
authorities, it abounds in the Himalaya Mountains; and is well known,
according to Major Madden, at Almora, where investigation showed it
to be, at least in this locality, the roots of the fragrant khus-khus
grass, which at certain times, as rainy nights, was luminous.
In South America and Asia occurs a plant known to science as
_Euphorbia phosphorea_; which emits, when severed or cut, a milky
juice somewhat resembling that of the dandelion. At night the juice of
the former is, when heated, brilliantly phosphorescent; so much so,
that, according to M. Martins of Montpellier, if the stem be broken
and used as a pen, this _latex_ may be employed as a luminous
ink, the characters appearing in the dark as letters of fire. One of
the most familiar exhibitions of vegetable luminosity is seen in the
“touchwood” or “fox-fire,” which many a schoolboy has employed in the
perpetuation of a practical joke. It is found about old decayed trees,
and is simply rotten wood permeated by the mycelium of fungi, which is
luminous in the dark. This simple luminant is often quite sufficient
to enable one to read large print, and is often the cause of laughable
episodes among camping-parties. A friend of the writer, in building a
camp-fire in the deep woods, hauled an old log to the door of the tent,
and there broke it up, making a fire about which the men slept. In the
night, after the fire was extinguished, one of the party awoke, and
with a shout aroused the rest, who sprang to their feet, believing that
they were lying among coals; as all about were masses of wood seemingly
at a white heat, but which investigation showed to be fox-fire.
This luminous decayed wood often rolls out from trees in the forests,
to the astonishment or alarm of animals unfamiliar with fire.
Perhaps the most remarkable exhibition of fox-fire is recorded by the
Rev. M. J. Berkeley, who says, “A quantity of wood had been purchased
in a neighboring parish, which was dragged up a very steep hill to
its destination. Amongst them was a log of larch or spruce, it is not
quite certain which, twenty-four feet long, and a foot in diameter.
Some young friends happened to pass up the hill at night, and were
surprised to find the road scattered with luminous patches, which,
when more closely examined, proved to be portions of bark or little
fragments of wood. Following the track, they came to a blaze of white
light which was perfectly surprising; on examination it appeared that
the whole of the inside of the bark of the log was covered with a white
byssoid mycelium of a peculiarly strong smell, but unfortunately in
such a state that the perfect form could not be ascertained. This was
luminous; but the light was by no means so bright as in those parts of
the wood where the spawn had penetrated more deeply, and where it was
so intense that the roughest treatment scarcely seemed to check it. If
any attempt was made to rub off the luminous matter, it only shone the
more brightly; and when wrapped up in five folds of paper the light
penetrated through all the folds on either side as brightly as if the
specimen was exposed; when, again, the specimens were placed in the
pocket, the pocket when opened was a mass of light. The luminosity
had now been going on for three days. Unfortunately we did not see it
ourselves till the third day, when it had, possibly from a change in
the state of electricity, been somewhat impaired; but it was still most
interesting, and we have merely recorded what we saw ourselves. It
was almost possible to read the time on the face of a watch, even in
its less luminous condition. We do not for a moment suppose that the
mycelium is essentially luminous, but are rather inclined to believe
that a peculiar occurrence of climatic conditions is necessary for the
production of the phenomenon, which is certainly one of great rarity.
Observers as we have been of fungi in their native haunts for fifty
years, it has never fallen to our lot to witness a similar case before;
though Professor Churchill Babington once sent us specimens of luminous
wood, which had, however, lost their luminosity before they arrived.
It should be observed that the parts of the wood which were most
luminous were not only deeply penetrated by the more delicate parts
of the mycelium, but were those which were most decomposed. It is
probable, therefore, that this fact is an element in the case as well
as the presence of fungoid matter.”
[Illustration:
PLATE XXII.
LUMINOUS FISH.
(_Malacosteus niger._)
With two luminous disks, one emitting a golden, the other a
greenish light.]
Any one who has wandered among old tree-trunks in search of insects,
or been a careful observer in underground nooks and corners, must have
seen the white tangles, often of beautiful shape, which constitute the
forms of some fungi. They are frequently to be seen under old boards in
frost-like designs of great delicacy, and many of these are supposed
by some to have a certain relation to luminous woods. Around old
tree-stumps, the decayed arms of the oak especially, long, cylindrical,
flexible branches with a hard bark covering are often found. When
freshly broken, the interior is pure white, later changing to a more
or less deep brown tint. The white, flocculent extremities form the
mycelium of the fungus known as _Rhizomorpha subterranea_, one of
the most interesting of the luminous plants. Its mystic light is often
seen in caves, where the rootlets have made their way, gleaming with a
soft phosphorescence.
In coal-mines this plant is quite common, and has been especially
observed near Dresden. Ehrman speaks in enthusiastic terms of these
“vegetable glow-worms,” as he calls them, which he observed gleaming on
the walls and in the crevices of Swedish mines.
In Bohemia the caves are not uncommonly illumined by this interesting
cryptogam; and, according to Phipson, sufficient light has been emitted
in English coal-mines from this source to enable miners to read
ordinary print. In the mines of North Hesse, Germany, the conditions
are particularly favorable for such displays, the gleams being
described as resembling moonbeams stealing through the gloomy caverns.
That this fungus is luminous when detached, is shown by the following
from M. Tulasue, in the “Annals of Natural Science,” 1848. “On
the evening of the day I received the specimens,” he writes, “the
temperature being about 22° C., all the young branches brightened with
an uniform phosphoric light the whole of their length. It was the same
with the surface of some of the older branches, the greater number of
which were still brilliant in some parts, and only on their surface. I
split and lacerated many of these twigs, but their internal substance
remained dull. The next evening, on the contrary, this substance,
having been exposed to contact with the air, exhibited at its surface
the same brightness as the bark of the branches. Prolonged friction
of the luminous surfaces reduced the brightness, and dried them to a
certain degree, but did not leave on the fingers any phosphorescent
matter.” And again, “By preserving these _Rhizomorphæ_ in an
adequate state of humidity, I have been able for many evenings to
renew the examination of their phosphorescence; the commencement of
desiccation, long before they really perish, deprives them of the
faculty of giving light.”
Rumphius, the celebrated botanist, was perhaps the first European
to discover the phosphorescence of fungi, observing it in a large
specimen on the island of Amboine, which he named _Fungus igneus_, or
fire-mushroom. In America such exhibitions are rare. Mr. H. K. Morrell,
editor of “The Gardiner (Me.) Home Journal,” informed me some few years
ago that he had observed the phosphorescence of _Tianus stypticus_ in
his garden; the young of which, being especially brilliant, emitted
a steady light. In Brazil a certain agaric is famous for its vivid
luminosity. It was observed by Mr. Gardner in 1840, who says, referring
to the species which has been named _Agaricus gardneri_, “One dark
night about the beginning of December, while passing along the streets
of the Villa de Natividate, Goyaz, Brazil, I observed some boys amusing
themselves with some luminous object, which I at first supposed to be
a kind of large fire-fly; but, on making inquiry, I found it to be a
beautiful phosphorescent species of _Agaricus_, and was told that it
grew abundantly in the neighborhood on the decaying fronds of a dwarf
palm. The whole plant gives out at night a bright phosphorescent light,
somewhat similar to that emitted by the larger fire-flies, having a
pale greenish hue. From this circumstance, and from growing on a palm,
it is called by the inhabitants ‘Flor de Coco.’”
Dr. Cuthbert Collingwood had a similar experience with an allied
species in Borneo. “The night being dark, the fungi could be very
distinctly seen, though not at any great distance, shining with a soft,
pale greenish light. Here and there spots of much more intense light
were visible, and these proved to be very young and minute specimens.
The older specimens may more properly be described as possessing a
greenish, luminous glow like the glow of the electric discharge; which,
however, was quite sufficient to define its shape, and when closely
examined, the chief details of its form and appearance. The luminosity
did not impart itself to the hand, and did not appear to be affected
by the separation from the root on which it grew, at least not for
some hours. I think it probable that the mycelium of this fungus is
also luminous; for, upon turning up the ground in search of small,
luminous worms, minute spots of light were observed, which could not be
referred to any particular object or body, when brought to the light
and examined, and were probably due to some minute portions of its
mycelium.” Mr. Hugh Low has stated that “he saw the jungle all in a
blaze of light, by which he could see to read, as some years ago he was
riding across the island by the jungle road, and that this luminosity
was produced by an agaric.”
Australia has produced a number of luminous toadstools. Drummond found
some striking forms near Swan River. He had noticed two species growing
as parasites on the stumps of trees. Their appearance in the daytime
did not attract particular attention; but at night they developed into
veritable plant lamps, exceeding any thing that he had ever seen. One
was about two inches across, and grew in clusters on the stump of a
banksia-tree which was surrounded by water. When the little plant was
secured from its miniature island home, it could have been used as a
lamp for several successive nights, a newspaper being read by placing
the agaric on it, the light illuminating the type in the immediate
vicinity. As the plant dried, the light gradually diminished.
[Illustration:
PLATE XIII.
LUMINOUS MUSHROOMS.
LUMINOUS INSECT. (_Geophilus electricus._)]
Later Mr. Drummond found a giant specimen that was sixteen inches in
diameter and a foot high, a veritable chandelier. He says regarding it,
“This specimen was hung up inside the chimney of our sitting-room to
dry; and, on passing through the apartment in the dark, I observed the
fungus giving out a most remarkable light, similar to that described
above. No light is so white as this, at least none that I have ever
seen. The luminous property continued, though gradually diminishing,
for four or five nights, when it ceased on the plant becoming dry. We
called some of the natives, and showed them this fungus when emitting
light. The room was dark, for the fire was very low and the candles
extinguished; and the poor creatures cried out, ‘Chinga,’ their name
for a spirit, and seemed afraid of it.”
A very attractive agaric, _Agaricus olearius_ (Plate XIII.), is
found at the foot of olive-trees in Southern Europe. During the daytime
the color is yellow, but observed at night it emits a brilliant blue
light. Like the Australian species, it continues to emit light after
it has been taken from the ground, the phosphorescence persisting
for successive nights. So brilliant are the gleams, that they may be
perceived at times before darkness sets in. Experiment showed that
the light was extinguished when the temperature was below +90° to
+6° C.; but the luminosity was not destroyed, as it re-appeared when
the temperature was raised above this point. If kept some time in
a temperature below freezing, it loses its light-emitting property
entirely. It gleams as brightly under water as out; pure oxygen seems
to have no effect upon it, and the most careful experiments fail to
show the slightest elevation of temperature about the parts which
shine. The light seems to emanate from the head (_pileus_) of the
fungus, the _lamellæ_ of the latter, where the seeds are found,
being the centre of the luminous phenomenon.
These interesting light-givers are perhaps more common than we are
aware of, from the fact that nocturnal investigations in the woods are
not frequent, nearly all the discoveries being the result of accident.
A small, luminous fungus has been observed in the Andaman Islands.
Gandichand found one in Manilla, while Dr. Hooker, as we have seen,
refers to the presence of one in the Sikkim Himalayas.
These curious families of fungi are not only ornamental, but useful.
In European countries the common mushroom[46] enjoys the widest
popularity as an esculent, especially the cultivated varieties. The
meadow mushroom is scarcely inferior, though stronger in flavor, and is
preferred by many to the cultivated species. In France the champignon
is largely eaten; and in Austria a kind which has no admirers in
England finds a constant place in the markets during the summer.
Truffles and morels are favorites not only in Europe, but also in the
vales of Cashmere, where two or three species of morels are dried for
consumption throughout the year. The great puff-ball is increasing
in reputation as a breakfast delicacy in Great Britain, while the
chantarelle and the hedgehog fungus are esteemed by many.
Numerous other species are more or less eaten by mycophagists,
although they are never found in the public markets. A species of
_Boletus_, cut in slices and dried, may be purchased throughout
the year in most of the Continental cities. In Tahiti the Jew’s ear[47]
is dried in large quantities and exported to China; while a species of
agaric comes into the markets of Singapore, and another dried agaric
is sent from the Cabul hills and the plains of north-western India.
Several species of _Cyttaria_ are eaten in the southern parts of
South America, and in Australia a native kind[48] is a favorite article
of food. Indeed, a very long catalogue might be made of the species
which are more or less consumed in different parts of the world.
The cultivation of fungi for esculent purposes has not hitherto
been successful with any other species than the ordinary mushroom.
Attempts were made in France to cultivate truffles, at first apparently
with considerable promise, but ultimately without much satisfaction.
There is no good reason to suppose it impossible or improbable that
many species might be devoted to experiments in that direction. Some
species of _Polyporus_ have been employed as styptics, or beaten till
soft and used as amadon. One species in Burmah has a good reputation
as an anthelmintic. Some species of _Polysaccum_ and _Geaster_ are
employed medicinally in China. Species of _Elaphomyces_ were at one
time supposed to possess great virtues now deemed apocryphal. Ergot,
developed on rye, wheat, and the germen of various grasses, still
maintains its position in the pharmacopœia; but is almost the only
fungus now employed, and that sparingly, by the legitimate medical
practitioner.
In the Cardiff coal-mines an interesting plant is found, which emits
so brilliant a light, that the men have been able to “see their hands
by it,” and was visible at a distance of sixty feet. Mr. Worthington
Smith, who is an authority for this, observed the same phenomenon in
_Polyporus sulfureus_.
While various theories have been recorded as to the physiological cause
of the light in cryptogams, and many writers give the most careful
details of the structure of the luminous parts, we are unable to go a
step farther to explain the cause of the light which appears to be a
combustion, but does not consume.