Spontaneous combustion--In the absorption of air by powdered
charcoal--and of hydrogen by spongy platinum--Dobereiner’s
lamp--Spontaneous combustion in the bowels of the earth--Burning
cliffs--Burning soil--Combustion without flame--Spontaneous combustion
of human beings--Countess Zangari--Grace Pett--Natural fire-temples
of the Guebres--Spontaneous fires in the Caspian Sea--Springs of
inflammable gas near Glasgow--Natural light-house of Maracaybo--New
elastic fluids in their cavities--of gems--Chemical operation going
on in their cavities--Explosions produced in them by heat--Remarkable
changes of colour from chemical causes--Effects of the nitrous oxide
of Paradise gas when breathed--Remarkable cases described--Conclusion.
Among the wonderful phenomena which chemistry presents to us, there
are few more remarkable than those of spontaneous combustion, in which
bodies both animate and inanimate emit flames, and are sometimes
entirely consumed by internal fire. One of the commonest experiments
in chemistry is that of producing inflammation by mixing two fluids
perfectly cold. Becker, we believe, was the first person who discovered
that this singular effect was produced by mixing oil of vitriol with
oil of turpentine. Borrichios showed that aqua-fortis produced the
same effect as oil of vitriol. Tournefort proved that spirit of nitre
and oil of sassafras took fire when mixed; and Homberg discovered that
the same property was possessed by many volatile oils when mixed with
spirit of nitre.
Every person is familiar with the phenomena of heat and combustion
produced by fermentation. Ricks of hay and stacks of corn have been
frequently consumed by the heat generated during the fermentation
produced from moisture; and gunpowder-magazines, barns, and paper-mills
have been often burned by the fermentation of the materials which they
contained. Galen informs us that the dung of a pigeon is sufficient
to set fire to a house; and he assures us that he has often seen it
take fire when it had become rotten. Casati likewise relates, on good
authority, that the fire which consumed the great church of Pisa was
occasioned by the dung of pigeons that had for centuries built their
nests under its roof.
Among the substances subject to spontaneous combustion, pulverized
or finely-powdered charcoal is one of the most remarkable. During
the last thirty years no fewer than four cases of the spontaneous
inflammation of powdered charcoal have taken place in France. When
charcoal is triturated in tuns with bronze bruisers, it is reduced
into the state of the finest powder. In this condition it has the
appearance of an unctuous fluid, and it occupies a space three times
less than it does in rods of about six inches long. In this state of
extreme division it absorbs air much more readily than it does when
in rods. This absorption, which is so slow as to require several days
for its completion, is accompanied with a disengagement of heat which
rises from 340° to 360° nearly of Fahrenheit, and which is the true
cause of the spontaneous inflammation. The inflammation commences near
the centre of the mass, at the depth of five or six inches beneath
its surface, and at this spot the temperature is always higher than
at any other. Black charcoal, strongly distilled, heats and inflames
more easily than the orange, or that which is little distilled, or
than the charcoal made in boilers. The most inflammable charcoal
must have a mass of at least 66lbs. avoirdupois, in order that it
may be susceptible of spontaneous inflammation. With the other less
inflammable varieties, the inflammation takes place only in larger
masses.
The inflammation of powdered charcoal is more active in proportion
to the shortness of the interval between its carbonization and
trituration. The free admission of air to the surface of the charcoal
is also indispensable to its spontaneous combustion.
Colonel Aubert, to whom we owe these interesting results, likewise
found that when sulphur and saltpetre are added to the charcoal, it
loses its power of inflaming spontaneously. But as there is still an
absorption of air and a generation of heat, he is of opinion that it
would not be prudent to leave these mixtures in too large masses after
trituration.[34]
[34] See _Edinburgh Journal of Science_, New Series, No. viii. p. 274.
A species of spontaneous combustion, perfectly analogous to that now
described, but produced almost instantaneously, was discovered by
Professor Dobereiner of Jena in 1824. He found that when a jet of
hydrogen gas was thrown upon recently prepared spongy platinum, the
metal became almost instantly red hot, and set fire to gas. In this
case the minutely divided platinum acted upon the hydrogen gas in the
same manner as the minutely divided charcoal acted upon common air.
Heat and combustion were produced by the absorption of both gases,
though in the one case the effect was instantaneous, and in the other
was the result of a prolonged absorption.
[Illustration: _Fig. 78._]
This beautiful property of spongy platinum was happily applied to the
construction of lamps for producing an instantaneous light. The form
given to the lamp by Mr. Garden of London is shown in the annexed
figure, where AB is a globe of glass, fitting tightly into another
glass globe CD by a ground shoulder _m n_. The globe AB terminates
in a hollow tapering neck _m n o p_, on the lower end of which is
placed a small cylinder of zinc _o p_. A brass tube _a b c_, is
fitted at _a_ into the neck of the globe CD, and through this tube,
which is furnished with a stop-cock _d_, the gas can escape at the
small aperture _c_. A brass pin _c f_, carrying a brass box P, is made
to slide through a hole _h_, so that the brass box P, in which the
spongy platinum is placed, can be set at any required distance from
the aperture _c_. If sulphuric acid, diluted with an equal quantity of
water, is now poured into the vessel AB by its mouth at S, now closed
with a stopper, the fluid will descend through the tube _m n o p_, and
if the cock _d_ is shut, it will compress the air contained in CD. The
dilute acid thus introduced into CD will act upon the ring of zinc _o
p_, and generate hydrogen gas, which, after the atmospheric air in CD
is let off, will gradually fill the vessel CD, the diluted acid being
forced up the tube _o p m n_, into the glass globe AB. The ring of zinc
_o p_ floats on a piece of cork, so that when CD is full of hydrogen,
the diluted acid does not touch the zinc, and consequently is prevented
from producing any more gas. The instant, however, that any gas is let
off at _c_, the pressure of the fluid in the globe AB, and tube _m n o
p_, overcomes the elasticity of the remaining gas in CD, and forces the
diluted acid up to the zinc _o p_, so as to enable it to produce more
gas to supply what has been used.
The lamp being supplied with hydrogen in the manner now described,
it is used in the following manner. The spongy platinum in P being
brought near _c_, the cock _d_ is turned, and the gas is thrown upon
the platinum. An intense heat is immediately produced, the platinum
becomes red-hot, and the hydrogen inflames. A taper is then lighted at
the flame, and the cock _d_ is shut. Professor Cumming, of Cambridge,
found it necessary to cover up the platinum with a cap after every
experiment. This ingenious chemist likewise found, that, with platinum
foil the 9,000th part of an inch thick kept in a close tube, the
hydrogen was inflamed; but when the foil was only the 6,000th of an
inch thick, it was necessary to raise it previously to a red heat.
Spontaneous combustion is a phenomenon which occurs very frequently
and often to a great extent within the bowels of the earth. The heat
by which it is occasioned is produced by the decomposition of mineral
bodies and other causes. This heat increases in intensity till it is
capable of melting the solid materials which are exposed to it. Gases
and aqueous vapours of powerful elasticity are generated, new fluids
of expansive energy imprisoned in cavities under great pressure are
set free, and these tremendous agents, acting under the repressing
forces of the superincumbent strata, exhibit their power in desolating
earthquakes; or, forcing their way through the superficial crust of the
globe, they waste their fury in volcanic eruptions.
When the phenomena of spontaneous combustion take place near the
surface of the earth, its effects are of a less dangerous character,
though they frequently give birth to permanent conflagrations, which no
power can extinguish. An example of this milder species of spontaneous
combustion has been recently exhibited in the burning cliff at
Weymouth; and a still more interesting one exists at this moment near
the village of Bradley, in Staffordshire. The earth is here on fire,
and this fire has continued for nearly sixty years, and has resisted
every attempt that has been made to extinguish it. This fire, which
has reduced many acres of land to a mere calx, arises from a burning
stratum of coal about four feet thick and eight or ten yards deep, to
which the air has free access, in consequence of the main coal having
been dug from beneath it. The surface of the ground is sometimes
covered for many yards with such quantities of sulphur that it can be
easily gathered. The calx has been found to be an excellent material
for the roads, and the workmen who collect it often find large beds of
alum of an excellent quality.
A singular species of invisible combustion, or of combustion without
flame, has been frequently noticed. I have observed this phenomenon in
the small green wax tapers in common use. When the flame is blown out,
the wick will continue red-hot for many hours; and if the taper were
regularly and carefully uncoiled, and the room kept free from currents
of air, the wick would burn on in this way till the whole of the taper
is consumed. The same effects are not produced when the colour of the
wax is red. In this experiment the wick, after the flame is blown out,
has sufficient heat to convert the wax into vapour, and this vapour
being consumed without flame, keeps the wick at its red heat. A very
disagreeable vapour is produced during this imperfect combustion of the
wax.
Prof. Dobereiner, of Jena, observed that, when the alcohol in a spirit
of wine lamp was nearly exhausted, the wick became carbonized, and
though the flame disappeared, the carbonized part of the wick became
red-hot, and continued so while a drop of alcohol remained, provided
the air in the room was undisturbed. On one occasion the wick continued
red-hot for twenty-four hours, and a very disagreeable acid vapour was
formed.
[Illustration: _Fig. 79._]
On these principles depend the _lamp without flame_ which was
originally constructed by Mr. Ellis. It is shown in the annexed
figure, where AB is the lamp, and _h_ a cylindrical coil of platinum
wire, the hundredth part of an inch in diameter. This spiral is so
placed that four or five of the twelve coils of which the cylinder
consists are upon the wick, and the other seven or eight above it. If
the lamp is lighted, and continues burning till the cylindrical coil
is red-hot, then if the flame is blown out, the vapour which arises
from the alcohol will by its combustion keep the coils above the wick
red-hot, and this red heat will in its turn keep up the vaporization
of the alcohol till the whole of the alcohol is consumed. The heat of
the wire is always sufficient to kindle a piece of German fungus or
saltpetre paper, so that a sulphur match may at any time be lighted.
Mr. Gill found that a wick composed of twelve threads of the cotton
yarn commonly used for lamps will require half an ounce of alcohol to
keep the wire red-hot for eight hours. This lamp has been kept burning
for sixty hours; but it can scarcely be recommended for a bed-room, as
an acid vapour is disengaged during the burning of the alcohol. When
perfumes are dissolved in the alcohol, they are diffused through the
apartment during the slow combustion of the vapour.
A species of combustion without flame, and analogous to that which
has been described, is exhibited in the extraordinary phenomenon of
the spontaneous combustion of living bodies. That animal bodies are
liable to internal combustion, is a fact which was well known to the
ancients. Many cases which have been adduced as examples of spontaneous
combustion are merely cases of individuals who were highly susceptible
of strong electrical excitation. In one of these cases, however, Peter
Bovisteau asserts, that the sparks of fire thus produced, reduced to
ashes the hair of a young man; and John de Viana informs us, that the
wife of Dr. Freilas, physician to the Cardinal de Royas, Archbishop of
Toledo, emitted by perspiration an inflammable matter of such a nature,
that when the ribbon which she wore over her shift was taken from her,
and exposed to the cold air, it instantly took fire, and shot forth
like grains of gunpowder. Peter Borelli has recorded a fact of the very
same kind respecting a peasant whose linen took fire, whether it was
laid up in a box when wet, or hung up in the open air. The same author
speaks of a woman who, when at the point of death, vomited flames; and
Thomas Bartholin mentions this phenomenon as having often happened to
persons who were great drinkers of wine or brandy. Ezekiel de Castro
mentions the singular case of Alexandrinus Megetius, a physician, from
one of whose vertebræ there issued a fire which scorched the eyes of
the beholders; and Krantzius relates, that during the wars of Godfrey
of Bouillon, certain people of the territory of Nevers were burning
with invisible fire, and that some of them cut off a foot or a hand
where the burning began, in order to arrest the calamity. Nor have
these effects been confined to man. In the time of the Roman consuls
Gracchus and Juventius, a flame is said to have issued from the mouth
of a bull without doing any injury to the animal.
The reader will judge of the degree of credit which may belong to these
narrations when he examines the effects of a similar kind which have
taken place in less fabulous ages, and nearer our own times. John Henry
Cohausen informs us that a Polish gentleman in the time of the Queen
Bona Sforza, having drunk two dishes of a liquor called brandy-wine,
vomited flames, and was burned by them, and Thomas Bartholin[35] thus
describes a similar accident: “A poor woman at Paris used to drink
spirit of wine plentifully for the space of three years, so as to take
nothing else. Her body contracted such a combustible disposition, that
one night, when she lay down on a straw couch, she was all burned
to ashes except her skull and the extremities of her fingers.” John
Christ. Sturmius informs us, in the German Ephemerides, that in the
northern countries of Europe flames often evaporate from the stomachs
of those who are addicted to the drinking of strong liquors; and he
adds, “that seventeen years before, three noblemen of Courland drank by
emulation strong liquors, and two of them died scorched and suffocated
by a flame which issued from their stomachs.”
[35] Acta Medica et Philosophica Hafniensia, 1673.
One of the most remarkable cases of spontaneous combustion is that
of the Countess Cornelia Zangari and Bandi of Cesena, which has been
minutely described by the Reverend Joseph Bianchini, a prebend in the
city of Verona. This lady, who is in the sixty-second year of her age,
retired to bed in her usual health. Here she spent above three hours
in familiar conversation with her maid, and in saying her prayers; and
having at last fallen asleep, the door of her chamber was shut. As her
maid was not summoned at the usual hour, she went into the bed-room
to wake her mistress; but receiving no answer, she opened the window,
and saw her corpse on the floor in the most dreadful condition. At
the distance of four feet from the bed there was a heap of ashes. Her
legs, with the stockings on, remained untouched, and the head, half
burned, lay between them. Nearly all the rest of the body was reduced
to ashes. The air in the room was charged with floating soot. A small
oil lamp on the floor was covered with ashes, but had no oil in it; and
in two candlesticks, which stood upright upon a table, the cotton wick
of both the candles was left, and the tallow of both had disappeared.
The bed was not injured, and the blankets and sheets were raised on
one side, as if a person had risen up from it. From an examination
of all the circumstances of this case, it has been generally supposed
that an internal combustion had taken place; that the lady had risen
from her bed to cool herself, and that, in her way to open the window,
the combustion had overpowered her, and consumed her body by a process
in which no flame was produced which could set fire to the furniture
or the floor. The Marquis Scipio Maffei was informed by an Italian
nobleman who passed through Cesena a few days after this event, that
he heard it stated in that town, that the Countess Zangari was in
the habit, when she felt indisposed, of washing all her body with
camphorated spirit of wine.
So recently as 1744, a similar example of spontaneous combustion
occurred in our own country, at Ipswich. A fisherman’s wife, of the
name of Grace Pett, of the parish of St. Clement’s, had been in the
habit for several years of going down stairs every night, after she was
half undressed, to smoke a pipe. She did this on the evening of the 9th
of April, 1744. Her daughter, who lay in the same bed with her, had
fallen asleep, and did not miss her mother till she awaked early in
the morning. Upon dressing herself, and going down stairs, she found
her mother’s body lying on the right side, with her head against the
grate, and extended over the hearth, with her legs on the deal floor,
and appearing like a block of wood burning with a glowing fire without
flame. Upon quenching the fire with two bowls of water, the neighbours,
whom the cries of the daughter had brought in, were almost stifled with
the smell. The trunk of the unfortunate woman was almost burned to
ashes, and appeared like a heap of charcoal covered with white ashes.
The head, arms, legs, and thighs, were also much burned. There was no
fire whatever in the grate, and the candle was burned out in the socket
of the candlestick, which stood by her. The clothes of a child on one
side of her, and a paper screen on the other, were untouched: and the
deal floor was neither singed nor discoloured. It was said that the
woman had drunk plentifully of gin overnight in welcoming a daughter
who had recently returned from Gibraltar.
Among the phenomena of the natural world which are related to those
of spontaneous combustion, are what have been called the natural
fire-temples of the Guebres, and the igneous phenomena which are
seen in their vicinity. The ancient sect of the Guebres or Parsees,
distinguished from all other sects as the worshippers of fire,
had their origin in Persia; but, being scattered by persecution,
they sought an asylum on the shores of India. Those who refused
to expatriate themselves continued to inhabit the shores of the
Caspian Sea, and the cities of Ispahan, Yezd, and Kerman. Their great
fire-temple, called Attush Kudda, stands in the vicinity of Badku,
one of the largest and most commodious ports on the Caspian. In the
neighbourhood of this town the earth is impregnated with naphtha, an
inflammable mineral oil; and the inhabitants have no other fuel, and no
other light, but what is derived from this substance.
The remains of the ancient fire-temples of the Guebres are still
visible about ten miles to the north-east of the town. The temple in
which the deity is worshipped under the form of fire, is a space about
thirty yards square, surrounded with a low wall, and containing many
apartments. In each of these a small volcano of sulphureous fire issues
from the ground through a furnace or funnel in the shape of a Hindoo
altar. On closing the funnel, the fire is instantly extinguished;
and by placing the ear at the aperture, a hollow sound is heard,
accompanied with a strong current of cold air, which may be lighted
at pleasure by holding to it any burning substance. The flame is of a
pale, clear colour, without any perceptible smoke, and emits a highly
sulphureous vapour, which impedes respiration, unless when the mouth
is kept beneath the level of the furnace. This action on the lungs
gives the Guebres a wan and emaciated appearance, and oppresses them
with a hectic cough, which strangers also feel while breathing this
insalubrious atmosphere.
For about two miles in circumference, round the principal fire, the
whole ground, when scraped to the depth of two or three inches, has
the singular property of being inflamed by a burning coal. In this
case, however, it does not communicate fire to the adjacent ground: but
if the earth is dug up with a spade, and a torch brought near it, an
extensive but instantaneous conflagration takes place, in which houses
have often been destroyed, and the lives of the people exposed to
imminent danger.
When the sky is clear and the weather serene, the springs in their
ebullition do not rise higher than two or three feet; but in gloomy
weather, and during the prevalence of stormy clouds, the springs are
in a state of the greatest ebullition, and the naphtha, which often
takes fire spontaneously at the earth’s surface, flows burning in great
quantities to the sea, which is frequently covered with it, in a state
of flame, to the distance of several leagues from the shore.
Besides the fires in the temple, there is a large one which springs
from a natural cliff in an open situation, and which continually burns.
The general space in which this volcanic fire is most abundant is
somewhat less than a mile in circuit. It forms a low flat hill, sloping
to the sea, the soil of which is a sandy earth, mixed with stones. Mr.
Forster did not observe any violent eruption of flame in the country
around the Attush Kudda; but Kinneir informs us, that the whole country
round Badku has at times the appearance of being enveloped in flames.
“It often seems,” he adds, “as if the fire rolled down from the
mountains in large masses, and with incredible velocity; and during the
clear moonshine nights of November and December, a bright blue light is
observed at times to cover the whole western range. The fire does not
consume; and if a person finds himself in the middle of it, no warmth
is felt.”
The inhabitants apply these natural fires to domestic purposes, by
sinking a hollow cane or merely a tube of paper, about two inches in
the ground, and by blowing upon a burning coal held near the orifice
of the tube, there issues a slight flame, which neither burns the cane
nor the paper. By means of these canes or paper tubes, from which the
fire issues, the inhabitants boil the water in their coffee-urns, and
even cook different articles of food. The flame is put out by merely
plugging up the orifice. The same tubes are employed for illuminating
houses that are not paved. The smell of naphtha is of course diffused
through the house: but after any person is accustomed to it, it ceases
to be disagreeable. The inhabitants also employ this natural fire
in calcining lime. The quantity of naphtha procured in the plain to
the south-east of Badku is enormous. It is drawn from wells, some of
which yield from 1,000 to 1,500lbs. per day. As soon as these wells
are emptied, they fill again till the naphtha rises to its original
level.[36]
[36] See Forster’s Travels, and Kinneir’s Geog. Memoir.
Inflammable gases issuing from the earth have been used both in
the old and the new world for domestic purposes. In the salt mine
of Gottesgabe, at Rheims, in the county of Fecklenburg, there is a
pit called the _Pit of the Wind_, from which a constant current of
inflammable gas has issued for sixty years. M. Roeder, the inspector of
the mines, has used this gas for two years, not only as a light, but
for all the purposes of domestic economy. In the pits which are not
worked, he collects the gas, and conveys it in tubes to his house. It
burns with a white and brilliant flame, has a density of about O.66,
and contains traces of carbonic acid gas and sulphuretted hydrogen.[37]
[37] _Edinburgh Journal of Science_, No. xv., p. 183.
Near the village of Fredonia, in North America, on the shores of
Lake Erie, are a number of burning springs, as they are called. The
inflammable gas which issues from these springs is conveyed in pipes
to the village, which is actually lighted by them.[38]
[38] _Edinburgh Journal of Science_, No. xv., p. 183.
In the year 1828 a copious spring of inflammable gas was discovered in
Scotland, in the bed of a rivulet which crosses the north road between
Glasgow and Edinburgh, a little to the east of the seventh mile-stone
from Glasgow, and only a few hundred yards from the house of Bedlay.
The gas is said to issue for more than half a mile along the banks of
the rivulet. Dr. Thompson, who has analysed the gas, saw it issuing
only within a space about fifty yards in length, and about half as much
in breadth. “The emission of gas was visible in a good many places
along the declivity to the rivulet in the immediate neighbourhood of a
small farm-house. The farmer had set the gas on fire in one place about
a yard square, out of which a great many small jets were issuing. It
had burnt without interruption during five weeks, and the soil (which
was clay) had assumed the appearance of pounded brick all around.
“The flame was yellow and strong, and resembled perfectly the
appearance which _carburetted hydrogen gas_ or _fire-damp_ presents
when burnt in daylight. But the greatest issue of gas was in the
rivulet itself, distant about twenty yards from the place where the gas
was burning. The rivulet, when I visited the place, was swollen and
muddy, so as to prevent its bottom from being seen. But the gas issued
up through it in one place with great violence, as if it had been in a
state of compression under the surface of the earth; and the thickness
of the jet could not be less than two or three inches in diameter. We
set the gas on fire as it issued through the water. It burnt for some
time with a good deal of splendour; but as the rivulet was swollen,
and rushing along with great impetuosity, the regularity of the issue
was necessarily disturbed, and the gas was extinguished.” Dr. Thompson
found this gas to consist of _two_ volumes of hydrogen gas, and _one_
volume of vapour of carbon; and as its specific gravity was 0.555,
and as it issues in great abundance, he remarks that it might be used
for filling air-balloons. “Were we assured,” he adds, “that it would
continue to issue in as great abundance as at present, it might be
employed in lighting the streets of Glasgow.”[39]
[39] _Edinburgh Journal of Science_, No. 1, New Series, p. 71-75.
A very curious natural phenomenon, called the _Lantern_ or _Natural
Lighthouse_ of Maracaybo, has been witnessed in South America. A bright
light is seen every night on a mountainous and uninhabited spot on the
banks of the river Catatumbo, near its junction with the Sulia. It is
easily distinguished at a greater distance than _forty_ leagues, and as
it is nearly in the meridian of the opening of the Lake of Maracaybo,
navigators are guided by it as by a light-house. This phenomenon is
not only seen from the sea-coast, but also from the interior of the
country--at Merida, for example, where M. Palacios observed it for
two years. Some persons have ascribed this remarkable phenomenon to
a thunder-storm, or to electrical explosions which might take place
daily in a pass in the mountains; and it has even been asserted,
that the rolling of thunder is heard by those who approach the spot.
Others suppose it to be an air-volcano, like those on the Caspian Sea,
and that it is caused by asphaltic soils like those of Mena. It is
more probable, however, that it is a sort of carburetted hydrogen, as
hydrogen gas is disengaged from the ground in the same district.[40]
[40] Humboldt’s Personal Narrative, vol. iv. p. 254, note.
Grand as the chemical operations are which are going on in the great
laboratory of Nature, and alarming as their effects appear when they
are displayed in the terrors of the earthquake and the volcano, yet
they are not more wonderful to the philosopher than the minute though
analogous operations which are often at work near our own persons,
unseen and unheeded. It is not merely in the bowels of the earth
that highly expansive elements are imprisoned and restrained, and
occasionally called into tremendous action by the excitation of heat
and other causes. Fluids and vapours of a similar character exist in
the very gems and precious stones which science has contributed to
luxury and to the arts.
In examining with the microscope the structure of mineral bodies, I
discovered in the interior of many of the gems thousands of cavities
of various forms and sizes. Some had the shape of hollow and regularly
formed crystals; others possessed the most irregular outline, and
consisted of many cavities and branches united without order, but
all communicating with each other. These cavities sometimes occurred
singly, but most frequently in groups forming strata of cavities, at
one time perfectly flat and at another time curved. Several such
strata were often found in the same specimen, sometimes parallel to
each other, at other times inclined, and forming all varieties of
angles with the faces of the original crystal.
These cavities, which occurred in _sapphire_, _chrysoberyl_, _topaz_,
_beryl_, _quartz_, _amethyst_, _peridot_, and other substances, were
sometimes sufficiently large to be distinctly seen by the naked eye,
but most frequently they were so small as to require a high magnifying
power to be well seen, and often they were so exceedingly minute, that
the highest magnifying powers were unable to exhibit their outline.
[Illustration: _Fig. 80._]
The greater number of these cavities, whether large or small, contained
two new fluids different from any hitherto known, and possessing
remarkable physical properties. These two fluids are in general
perfectly transparent and colourless, and they exist in the same cavity
in actual contact, without mixing together in the slightest degree. One
of them expands _thirty_ times more than water, and at a temperature of
about 80° of Fahrenheit it expands so as to fill up the vacuity in the
cavity. This will be understood from the annexed figure, where A B C D
is the cavity, _m n p o_ the highly expansible fluid in which at low
temperatures there is always a vacuity V, like an air-bubble in common
fluids, and A _m n_, C _o p_, the second fluid occupying the angles A
and C. When heat such as that of the hand is applied to the specimen,
the vacuity V gradually contracts in size, and wholly vanishes at a
temperature of about 80°, as shown in Fig. 81. The fluids are shaded,
as in these two figures, when they are seen by light reflected from
their surfaces.
[Illustration: _Fig. 81._]
[Illustration: _Fig. 82._]
When the cavities are large, as in Fig. 82, compared with the quantity
of expansible fluid _m n p o_, the heat converts the fluid into vapour,
an effect which is shown by the circular cavity V becoming larger and
larger till it fills the whole space _m n o p_.
When any of these cavities, whether they are filled with fluid
or with vapour, is allowed to cool, the vacuity V reappears at a
certain temperature. In the fluid cavities the fluid contracts, and
the small vacuity appears, which grows larger and larger till it
resumes its original size. When the cavities are large, several small
vacuities make their appearance and gradually unite into one, though
they sometimes remain separate. In deep cavities a very remarkable
phenomenon accompanies the reappearance of the vacuity. At the instant
that the fluid has acquired the temperature at which it quits the
sides of the cavity, an effervescence or rapid ebullition takes place,
and the transparent cavity is for a moment opaque, with an infinite
number of minute vacuities, which instantly unite into one that goes
on enlarging as the temperature diminishes. In the vapour cavities the
vapour is reconverted by the cold into fluid, and the vacuity V, Fig.
82, gradually contracts till all the vapour has been precipitated. It
is curious to observe, when a great number of cavities are seen at once
in the field of the microscope, that the vacuities all disappear and
reappear at the same instant.
While all these changes are going on in the expansive fluid, the
other denser fluid at A and C, Fig. 80, 81, remains unchanged either
in its form or magnitude. On this account I experienced considerable
difficulty in proving that it was a fluid. The improbability of two
fluids existing in a transparent state in absolute contact, without
mixing in the slightest degree, or acting upon each other, induced
many persons to whom I showed the phenomenon to consider the lines _m
n_, _o p_, Fig. 80, 81, as a partition in the cavity, or the spaces A
_m n_, _o p_ C, either as filled with solid matter, or as corners into
which the expanding fluid would not penetrate. The regular curvature,
however, of the boundary line _m n_, _o p_, and other facts, rendered
these suppositions untenable.
[Illustration: _Fig. 83._]
This difficulty was at last entirely removed by the discovery of a
cavity of the form shown in the annexed figure, where A, B, and C are
three portions of the expansible fluid separated by the interposition
of the second fluid D E F. The first portion A of the expansible fluid
had four vacuities V, X, Y, Z, while the other two portions B, C, had
no vacuity. In order to determine if the vacuities of the portions B,
C, had passed over to A, I took an accurate drawing of the appearances
at a temperature of 50°, as shown in the figure, and I watched the
changes which took place in raising the temperature to 83°. The portion
A gradually expanded itself till it filled up all the four vacuities
V, X, Y, and Z, but as the portions B, C, had no vacuities, they could
expand themselves only by pushing back the supposed second fluid D E
F. This effect actually took place. The dense fluid quitted the side
of the cavity at F. The two portions B, C, of the expansible fluid
instantly united, and the dense fluid having retreated to the limit _m_
_n_ _o_, its other limit advanced to _p_ _q_ _r_, thus proving it to
be a real fluid. This experiment, which I have often shown to others,
involves one of those rare combinations of circumstances which nature
sometimes presents to us in order to illustrate her most mysterious
operations. Had the portions B, C, been accompanied, as is usual, with
their vacuities, the interposed fluid would have remained immoveable
between the two equal and opposite expansions; but owing to the
accidental circumstance of these vacuities having passed over into the
other branch A of the cavity, the fluid yielded to the difference of
the expansive forces between which it lay, and thus exhibited its fluid
character to the eye.
[Illustration: _Fig. 84._]
When we examine these cavities narrowly, we find that they are actually
little laboratories, in which chemical operations are constantly going
on, and beautiful optical phenomena continually displaying themselves.
Let A B D C, for example, be the summit of a crystallized cavity in
topaz, S S representing the dense, N N the expansible fluid, bounded
by a circular line _a b c d_, and V V the vacuity in the new fluid,
bounded by the circle _e f g h_. If the face A B D C is placed under a
compound microscope, so that light may be reflected at an angle less
than that of total reflexion, and if the observer now looks through
the microscope, the temperature of the room being 50°, he will see the
second fluid S S shining with a very feeble reflected light, the dense
fluid N N with a light perceptibly brighter, and the vacuity V V with
a light of considerable brilliancy. The boundaries _a b c d_, _e f g
h_, are marked by a well-defined outline, and also by the concentric
coloured rings of thin plates produced by the extreme thinness of each
of the fluids at their edges.
If the temperature of the room is raised slowly to 58°, a brown
spot will appear at _x_ in the centre of the vacuity V V. This spot
indicates the commencement of evaporation from the expansible fluid
below, and arises from the partial precipitation of the vapour in the
roof of the cavity. As the heat increases, the brown spot enlarges and
becomes very dark. It is then succeeded by a white spot and one or
more coloured rings rise in the centre of the vacuity. The vapour then
seems to form a drop, and all the rings disappear by retiring to the
centre, but only to reappear with new lustre. During the application
of heat, the circle _e f g h_ contracts and dilates like the pupil of
the eye. When the vaporization is so feeble as to produce only a single
ring of one or two tints of the second order, they vanish instantly
by breathing upon the crystal; but when the slight heat of the breath
reaches the fluid, it throws off fresh vapour, and the rings again
appear.
If a drop of ether is put upon the crystal when the rings are in a
state of rapid play, the cold produced by its evaporation causes them
to disappear, till the temperature again rises. When the temperature
is perfectly uniform, the rings are stationary, as shown between V and
V in fig. 84; and it is interesting to observe the first ring produced
by the vapour swelling out to meet the first ring at the margin of
the fluid, and sometimes coming so near it that the darkest parts of
both form a broad black band. As the heat increases, the vacuity V V
diminishes and disappears at 79°, exhibiting many curious phenomena,
which we have not room to describe.
Having fallen upon a method of opening the cavities, and looking at the
fluids, I was able to examine their properties with more attention.
When the expansible fluid first rises from the cavity upon the surface
of the topaz, it neither remains still like the fixed oils, nor
disappears like evaporable fluids. Under the influence, no doubt, of
heat and moisture, it is in a state of constant motion, now spreading
itself on a thin plate over a large surface, and now contracting itself
into a deeper and much less extended drop. These contractions and
extensions are marked by very beautiful optical phenomena. When the
fluid has stretched itself out into a thin plate, it ceases to reflect
light like the thinnest part of the soap-bubble; and when it is again
accumulated into a thicker drop, it is covered with thin coloured rings
of thin plates.
After performing these motions, which sometimes last for ten minutes,
the fluid suddenly disappears, and leaves behind it a sort of granular
residue. When examining this with a single microscope, it again started
into a fluid state, and extended and contracted itself as before. This
was owing to the humidity of the hand which held the microscope, and
I have been able to restore by moisture the fluidity of these grains
twenty days after they were formed from the fluid. This portion was
shown to the Rev. Dr. Fleming, who remarked, that, had he observed
it accidentally, he would have ascribed its apparent vitality to the
movements of some of the animals of the genus Planaria.
After the cavity has remained open for a day or two, the dense fluid
comes out and quickly hardens into a transparent and yellowish
resinous-looking substance, which absorbs moisture, though with less
avidity than the other. It is not volatilized by heat, and is insoluble
in water and alcohol. It readily dissolves, however, with effervescence
in the sulphuric, nitric, and muriatic acids. The residue of the
expansible fluid is volatilized by heat, and is dissolved, but without
effervescence, in the above-mentioned acids. The refractive power of
the dense fluid is about 1.295, and of the expansible one 1.131.
The particles of the dense fluid have a very powerful attraction for
each other and for the mineral which contains them, while those of
the expansible fluid have a very slight attraction for one another,
and also for the substance of the mineral. Hence the two fluids never
mix, the dense fluid being attracted to the angles of angular cavities,
or filling the narrow necks by which two cavities communicate. The
expansible fluid, on the other hand, fills the wide parts of the
cavities, and in deep and round cavities it lies above the dense fluid.
When the dense fluid occupies the necks which join two cavities,
it performs the singular function of a fluid valve, opening and
shutting itself according to the expansions or contractions of the
other fluid. The _fluid valves_ thus exhibited in action may suggest
some useful hints to the mechanic and the philosopher, while they
afford ground of curious speculation in reference to the functions of
animal and vegetable bodies. In the larger organizations of ordinary
animals, where gravity must in general overpower, or at least modify,
the influence of capillary attraction, such a mechanism is neither
necessary nor appropriate; but, in the lesser functions of the same
animals, and in almost all the microscopic structures of the lower
world, where the force of gravity is entirely subjected to the more
powerful energy of capillary forces, it is extremely probable that the
mechanism of immiscible fluids and fluid valves is generally adopted.
In several cavities in minerals I have found crystallized and other
bodies, sometimes transparent crystals, sometimes black spicular
crystals, and sometimes black spheres, all of which are moveable within
the cavity. In some cavities the two new fluids occur in an indurated
state, and others I have found to be lined with a powdery matter. This
last class of cavities occurred in topaz, and they were distinguished
from all others by the extraordinary beauty and symmetry of their
form. One of these cavities represented a finely ornamented sceptre,
and, what is still more singular, the different parts of which it is
composed lay in different planes.
When the gem which contains the highly expansive fluid is strong, and
the cavity not near the surface, heat may be applied to it without
danger; but in the course of my experiments on this subject, the
mineral has often burst with a tremendous explosion, and in one case
wounded me on the brow. An accident of the same kind occurred to a
gentleman who put a crystal into his mouth for the purpose of expanding
the fluid. The specimen burst with great force and cut his mouth, and
the fluid which was discharged from the cavity had a very disagreeable
taste.
In the gems which are peculiarly appropriated for female ornaments,
cavities containing the expansive fluid frequently occur, and if these
cavities should happen to be very near the surface or the edge of the
stone, the fever heat of the body might be sufficient to burst them
with an alarming and even dangerous explosion. I have never heard of
any such accident having occurred; but if it has, or if it ever shall
occur, and if its naturally marvellous character shall be heightened by
any calamitous results, the phenomena described in the preceding pages
will strip it of its wonder.
There are no facts in chemistry more interesting than those which
relate to the changes of colour, which are produced by the mixture of
fluids, and to the creation of brilliant colours by the combination
of bodies in which no colouring matter is visible. Facts of this kind
are too common and too generally known to require to be noticed in a
work like this. The art of producing such changes was known to some of
the early impostors, who endeavoured to obtain a miraculous sanction
to their particular dogmas. Marcos, the head of one of the sects that
wished to engraft paganism upon Christianity, is said to have filled
three transparent glasses with white wine, and while he prayed, the
wine in one of the glasses became red like blood, that in another
became purple, and that in the third sky-blue. Such transformations
present no difficulty to the chemist. There are several fluids, such
as some of the coloured juices of plants, which change their colour
rapidly and without any additional ingredient: and in other cases,
there would be no difficulty in making additions to fluids which should
produce a change of colour at any required instant.
A very remarkable experiment of an analogous nature has been publicly
exhibited in modern times. Professor Beyruss, who lived at the court
of the Duke of Brunswick, one day pronounced to his highness that the
dress which he wore should during dinner became red; and the change
actually took place, to the astonishment of the prince and the rest
of his guests. M. Vogel, who has recorded this curious fact, has not
divulged the secret of the German chemist; but he observes, that if
we pour lime-water into the juice of beet-root, we shall obtain a
colourless liquid; and that a piece of white cloth dipped in this
liquid and dried rapidly, will in a few hours become red by the mere
contact of air. M. Vogel is also of opinion that this singular effect
would be accelerated in an apartment where champagne or other fluids
charged with carbonic acid are poured out in abundance.
Among the wonders of chemistry we must number the remarkable effects
produced upon the human frame by the inhalation of _paradise_ or
_intoxicating gas_, as it has been called. This gas is known to
chemists by the name of the _nitrous oxide_, or the _gaseous oxide of
azote_, or the _protoxide of nitrogen_. It differs from atmospheric
air only in the proportion of its ingredients, atmospheric air
being composed of twenty-seven parts of oxygen, and seventy-three
of nitrogen, while the nitrous oxide consists of thirty-seven parts
of oxygen, and sixty-seven of nitrogen. The most convenient way of
procuring the gas is to expose nitrate of ammonia in a tubulated
glass retort to the heat of an Argand’s lamp between 400° and 500° of
Fahrenheit. The salt first melts; bubbles of gas begin to rise from
the mass, and in a short time a brisk effervescence takes place, which
continues till all the salt has disappeared. The products of this
operation are the nitrous oxide and water, the watery vapour being
condensed in the neck of the retort, while the gas is received over
water. The gas thus obtained is generally white, and hence, when it
is to be used for the purposes of respiration, it should remain at
least an hour over water, which will absorb the small quantity of acid
and of nitrate of ammonia which adhere to it. A pound of the nitrate
of ammonia will in this way yield five cubic feet of gas fit for the
purpose of inhalation.
It was discovered by Sir Humphrey Davy, that this gas could be safely
taken into the lungs, and that it was capable of supporting respiration
for a few minutes. In making this experiment he was surprised to find
that it produced a singular species of intoxication, which he thus
describes: “I breathed,” says he, “three quarts of oxide from and into
a silk bag for more than half a minute without previously closing my
nose or exhausting my lungs. The first inspiration caused a slight
degree of giddiness. This was succeeded by an uncommon sense of fulness
in the head, accompanied with loss of distinct sensation and voluntary
power, a feeling analogous to that produced in the first stage of
intoxication, but unattended by pleasurable sensations.” In describing
the effects of another experiment, he says, “Having previously closed
my nostrils and exhausted my lungs, I breathed four quarts of nitrous
oxide from and into a silk bag. The first feelings were similar to
those produced in the last experiment, but in less than half a minute,
the respiration being continued, they diminished gradually, and were
succeeded by a highly pleasurable thrilling, particularly in the
chest and the extremities. The objects around me became dazzling, and
my hearing more acute. Towards the last respiration the thrilling
increased, the sense of muscular power became greater, and at last an
irresistible propensity to action was indulged in. I recollect but
indistinctly what followed; I knew that my motions were varied and
violent. These effects very rarely ceased after respiration. In ten
minutes I had recovered my natural state of mind. The thrilling in the
extremities continued longer than the other sensations. This experiment
was made in the morning; no languor or exhaustion was consequent, my
feelings through the day were as usual, and I passed the night in
undisturbed repose.”
In giving an account of another experiment with this gas, Sir Humphrey
thus describes his feelings: “Immediately after my return from a
long journey, being fatigued, I respired nine quarts of nitrous
oxide, having been precisely thirty-three days without breathing any.
The feelings were different from those I had experienced on former
experiments. After the first six or seven respirations, I gradually
began to lose the perception of external things, and a vivid and
intense recollection of some former experiments passed through my mind,
so that I called out, ‘What an annoying concatenation of ideas!’”
Another experiment made by the same distinguished chemist was attended
by still more remarkable results. He was shut up in an airtight
breathing-box, having a capacity of about nine and a half cubic feet,
and he allowed himself to be habituated to the excitement of the gas,
which was gradually introduced. After having undergone this operation
for an hour and a quarter, during which eighty quarts of gas were
thrown in, he came out of the box and began to respire twenty quarts
of unmingled nitrous oxide. “A thrilling,” says he, “extending from
the chest to the extremities, was almost immediately produced. I felt
a sense of tangible extension highly pleasurable in every kind; my
visible impressions were dazzling and apparently magnified; I heard
distinctly every sound in the room, and I was perfectly aware of my
situation. By degrees, as the pleasurable sensation increased, I lost
all connexion with external things; trains of vivid visible images
rapidly passed through my mind, and were connected with words in such
a manner as to produce perceptions perfectly novel. I existed in a
world of newly connected and newly modified ideas. When I was awakened
from this same delirious trance by Dr. Kinglake, who took the bag from
my mouth, indignation and pride were the first feelings produced by
the sight of the persons about me. My emotions were enthusiastic and
sublime, and for a moment I walked round the room, perfectly regardless
of what was said to me. As I recovered my former state of mind, I felt
an inclination to communicate the discoveries I had made during the
experiment. I endeavoured to recall the ideas; they were feeble and
indistinct. One recollection of terms, however, presented itself, and
with the most intense belief and prophetic manner I exclaimed to Dr.
Kinglake, ‘Nothing exists but thoughts; the universe is composed of
impressions, ideas, pleasures, and pains!’”
These remarkable properties induced several persons to repeat the
experiment of breathing this exhilarating medicine. Its effects were,
as might have been expected, various in different individuals; but its
general effect was to produce in the gravest and most phlegmatic the
highest degree of exhilaration and happiness unaccompanied with languor
or depression. In some it created an irresistible disposition to laugh,
and in others a propensity to muscular exertion. In some it impaired
the intellectual functions, and in several it had no sensible effect,
even when it was breathed in the purest state, and in considerable
quantities. It would be an inquiry of no slight interest to ascertain
the influence of this gas over persons of various bodily temperaments,
and upon minds varying in their intellectual and moral character.
Although Sir Humphrey Davy experienced no unpleasant effects from the
inhalation of the nitrous oxide, yet such effects are undoubtedly
produced; and there is reason to believe that even permanent changes
in the constitution may be induced by the operation of this remarkable
stimulant. Two very interesting cases of this kind presented themselves
to Professor Silliman, of Yale College, when the nitrous oxide was
administered to some of his pupils. The students had been in the habit,
for several years, of preparing this gas, and administering it to
one another, and these two cases were the only remarkable ones which
deserved to be recorded. We shall describe them in Professor Silliman’s
own words:--
“A gentleman, about nineteen years of age, of a sanguine temperament,
and cheerful temper, and in the most perfect health, inhaled the usual
quantity of the nitrous oxide, when prepared in the ordinary manner.
Immediately his feelings were uncommonly elevated, so that, as he
expressed it, he could not refrain from dancing and shouting. Indeed
to such a degree was he excited, that he was thrown into a frightful
fit of delirium, and his exertions became so violent, that after a
while he sank to the earth exhausted, and there remained, until having
by quiet in some degree recovered his strength, he again arose, only
to renew the most convulsive muscular efforts, and the most piercing
screams and cries; within a few moments, overpowered by the intensity
of the paroxysm, he again fell to the ground, apparently senseless, and
panting vehemently. The long continuance and violence of the affection
alarmed his companions, and they ran for professional assistance. They
were, however, encouraged by the person to whom they applied to hope
that he would come out of his trance without injury; but for the space
of two hours these symptoms continued; he was perfectly unconscious of
what he was doing, and was in every respect like a maniac. He states,
however, that his _feelings vibrated_ between perfect happiness and the
most consummate misery. In the course of the afternoon, and after the
first violent effects had subsided, he was compelled to lie down two or
three times from excessive fatigue, although he was immediately aroused
upon any one’s entering the room. The effects remained in a degree for
three or four days, accompanied by a hoarseness, which he attributed
to the exertion made while under the immediate influence of the gas.
This case should produce a degree of caution, especially in persons of
a sanguine temperament, whom, much more frequently than others, we have
seen painfully, and even alarmingly affected.”
The other case described by Professor Silliman was that of a man of
mature age, and of a grave and respectable character. “For nearly
two years previous to his taking the gas, his health had been very
delicate, and his mind frequently gloomy and depressed. This was
peculiarly the case for a few days immediately preceding that time;
and his general state of health was such, that he was obliged almost
entirely to discontinue his studies, and was about to have recourse
to medical assistance. In this state of bodily and mental debility,
he inspired about three quarts of nitrous oxide. The consequences
were, an astonishing invigoration of his whole system, and the most
exquisite perceptions of delight. These were manifested by an uncommon
disposition for pleasantry and mirth, and by extraordinary muscular
power. The effects of the gas were felt without diminution for at least
thirty hours, and in a greater or less degree for more than a week.
“But the most remarkable effect was that _upon the organs of taste_.
Antecedently to taking the gas, he exhibited no peculiar choice in
the articles of food, but immediately subsequent to that event, he
_manifested a taste for such things only as were sweet_, and for
several days _ate nothing but sweet cake_. Indeed this singular taste
was carried to such excess, that he used _sugar and molasses, not
only upon his bread and butter, and lighter food, but upon his meat
and vegetables_. This he continues to do even at the present time;
and although eight weeks have elapsed since he inspired the gas, he
is still found _pouring molasses over beef, fish, poultry, potatoes,
cabbage, or whatever animal or vegetable food is placed before him_.
“His health and spirits since that time have been uniformly good, and
he attributes the restoration of his strength and mental energy to the
influence of the nitrous oxide. He is entirely regular in his mind, and
now experiences no uncommon exhilaration, but is habitually cheerful,
while before he was as habitually grave, and even to a degree gloomy.”
* * * * *
Such is a brief and general account of the principal phenomena of
Nature, and the most remarkable deductions of science, to which
the name of Natural Magic has been applied. If those who have not
hitherto sought for instruction and amusement in the study of the
material world, shall have found a portion of either in the preceding
pages, they will not fail to extend their inquiries to other popular
departments of science, even if they are less marked with the
attributes of the marvellous. In every region of space, from the
infinitely distant recesses of the heavens to the “dark unfathomed
caves of ocean,” the Almighty has erected monuments of miraculous
grandeur, which proclaim the power, the wisdom, and the beneficence
of their Author. The inscriptions which they bear--the hand-writing
which shines upon their walls--appeal to the understanding and to
the affections, and demand the admiration and the gratitude of every
rational being. To remain willingly ignorant of these revelations of
the Divine Power is a crime next to that of rejecting the revelation
of the Divine Will. Knowledge, indeed, is at once the handmaid and the
companion of true religion. They mutually adorn and support each other;
and beyond the immediate circle of our secular duties, they are the
only objects of rational ambition. While the calm deductions of reason
regulate the ardour of Christian zeal, the warmth of a holy enthusiasm
gives a fixed brightness to the glimmering lights of knowledge.
It is one of the darkest spots in the history of man, that these noble
gifts have been so seldom combined. In the young mind alone can the two
kindred seeds be effectually sown; and among the improvements which
some of our public institutions require, we yet hope to witness a
national system of instruction, in which the volumes of Nature and of
Revelation shall be simultaneously perused.