CHAPTER V.

Chemical wonders--Ice obtained in a red-hot vessel--The

corpse candles of Wales--Luminous appearances after

death--Sadoomeh the magician--The laughing gas--Sulphuric

ether--Chloroform--Gunpowder compared with gun-cotton.

The word chemistry is, probably, derived from a Coptic root, signifying

obscure or secret; and the German word _geheim_ is traced to the same

origin. The objects of this department of science are, to investigate

the nature and properties of the elements of matter and their mutual

actions and combinations; to ascertain the proportions in which they

unite and the modes of separating them when united; and to inquire into

the laws which affect and rule these agencies. A few of the wonders

connected with this science may, therefore, appropriately follow the

terrestrial phenomena which have just been considered.

The Romish church has rendered chemistry available in connexion

with one of its prodigies, the so-called blood of St. Januarius. A

substance is shown to the deluded worshippers in a phial, appearing

in a congealed state; but, as masses are performed by the priests,

it becomes fluid. The illusion practised in this case may, however,

be easily effected by reddening sulphuric ether with orchanet, the

_onosma_ of Linnæus, and then saturating the tincture with spermaceti.

This preparation is solid at ten degrees above the freezing point, and

melts and boils at twenty degrees. Let the phial which contains it when

coagulated, be held in the hand for a few minutes, and the temperature

of the substance rises, and it becomes fluid. Even the warmth of a

public assembly is sufficient for this purpose.

Marcus, the chief of one of the sects in the second century, who wished

to amalgamate with Christianity the doctrines and rules of pagan rites,

filled with white wine three cups of transparent glass; and, while

he was praying, the liquid in one of the cups became like blood; in

another, of a purple colour; and in the third, sky-blue. But these

effects might easily be produced by chemical action. Professor Beyruss,

at the court of the duke of Brunswick, promised that his white dress

should become red during a repast; and the change took place, to the

astonishment of the prince and his guests. M. Vogel, who relates this

fact, does not reveal the means employed; but observes that, by pouring

lime-water on the juice of beet-root, a colourless liquid is obtained,

that a piece of cloth dipped in it and quickly dried becomes red in a

few hours by the contact of the air alone; and that this effect may be

accelerated in a room where champagne and other beverages charged with

carbonic acid gas are abundantly used. Still more rapidly might the

chance be effected in some temple, in the midst of rising incense and

burning torches; and the veil which covered things deemed sacred, might

thus have been seen to change from white to the colour of blood--a

presage of fearful disasters.

A series of remarkable experiments was performed by professor Boutigny,

at the British Association at Cambridge, in 1845. He commenced by

showing, that when cold water is poured on a hot metallic surface, the

heat is not communicated to it; and that the water assumes a spheroidal

form, and continues to roll about, upheld at a minute distance from

the heated surface, without boiling. The water was poured into a hot

platinum cup kept in rapid motion, and resembled a small globe of

glass dancing about. There was no hissing noise nor appearance of

steam, though the globule of water must, nevertheless, have evaporated

rapidly; for, after gradually diminishing in size, in the course of

about two minutes it disappeared. The same result takes place when any

substance capable of assuming a globular form is placed on a heated

surface. In proof of this, the professor placed in the heated cup of

platinum, iodine, ammonia, and some inflammable substances; each of

which became globular, and danced about like the globule of water, but

without emitting smell or vapour, or being inflamed, until the platinum

cup was cooled.

Another experiment was yet more curious. Professor Boutigny heated a

silver weight, of the same shape as the weight of a clock, until it

was red-hot, and then lowered it by a wire into a glass of cold water,

without there being any more indication of action in the water than if

the weight had been quite cold. Professor Boutigny advanced no theory

to account for these peculiar actions, further than that a film of

vapour intervenes between the heated body and the substance, which

prevents the communication of heat. The facts, however, he thought

were of importance in a practical point of view, both as regards

the tempering of metals, and in the explanation of the causes of

steam-boiler explosions. It would seem, from experiments in tempering

metals, that, if the metal be too much heated, the effect of plunging

it into water will be diminished. In steam-boilers, also, if the

heated water be introduced into a heated surface, the heat may not

be communicated to the water, and the boiler may become red-hot, and

without any great emission of steam; until, at length, when the boiler

cools, a vast quantity of steam would become suddenly generated and the

boiler burst.

The last and most curious experiment performed by professor Boutigny,

was the freezing of water in a red-hot vessel. Having heated a platinum

cup red-hot, he poured into it a small quantity of water, which was

kept in a globular form, as in the other experiments. He then poured

into the cup some liquid sulphurous acid; when a sudden evaporation

ensued, and, on quickly inverting the cup, there came out a small mass

of ice. The principle of this experiment, which called forth loud

and continued applause, is this:--sulphurous acid has the property

of boiling water when it is at a temperature below the freezing

point; and, when poured into the heated vessel, the suddenness of the

evaporation occasions a degree of cold sufficient to freeze water.

Liquid carbonic acid takes a high position for its freezing qualities.

Mr. Adams, of Kensington, manufactures this curious liquid as an

article of commerce, and has, occasionally, as much as nine gallons of

it in store. In drawing it from its powerful reservoirs, it evaporates

so rapidly as to freeze, and it is then a light porous mass, like snow.

If a small quantity of this is drenched with ether, the degree of cold

produced is even more intolerable to the touch than boiling water; a

drop or two of the mixture producing blisters, just as if the skin had

been burned! Mr. Adams states that, in eight minutes he has frozen a

mass of mercury weighing ten pounds.

In one department of knowledge--that of vapours and gases--on which

chemistry casts so much light, we discover many remarkable phenomena.

Few persons have resided, for example, in the fenny and swampy

districts of our island, without seeing, at least occasionally, the

ignis fatuus, Will-o’-the-wisp, or Jack-o’-lantern, hovering a few

feet above the surface of stagnant water.

“Wild fires dancing o’er the heath,”

may be observed, indeed, at almost all times of the year, but it is

chiefly in autumn, and particularly in November, that they flit in mazy

circles and irregular evolutions; sometimes at the edge of a morass,

over the tops of withered sedges, reeds, and brushwood; and, at others,

over palings and hedgerows, or the still surface of the oozy bog.

It has been argued by some, that they are effects produced by luminous

insects, as the glow-worm, the gnat, and the mole-cricket. But this

theory is very unsatisfactory, and the cause which is now generally

acknowledged to be the real one, is far more natural. There is a

substance readily obtained, but of very offensive odour, called

phosphoret of lime; and, if a piece of this be taken and dropped into a

pool of water, little flames will be seen on its surface. These arise

from the power of the substance to decompose water, in consequence of

which, the hydrogen ascends to the surface, and ignites on coming in

contact with the air.

Dr. Weissenborn has given the following interesting statements:--“In

the year 1818, I was fortunate enough to get a fine view of the ignes

fatui operating on an extensive scale. I was then at Schnepfenthal,

in the duchy of Gotha; and in a clear November night, between eleven

and twelve o’clock, when I had just undressed, the bright moonshine

allured me to the window, to survey the expanse of boggy meadows, which

spread two or three English miles in length, a quarter-of-a-mile from

the foot of the hillock on which the house in which I then was, is

standing. Through the first third of the meadows there was a winding

rivulet, of the breadth of seven or eight feet, which then turns off

into an artificial bed, whilst the old bed continues in the direction

of the meadows, which are bounded on one side by a range of brushwood,

and on the other by cultivated grounds, with marshy dells here and

there. My intimate acquaintance with the locality, together with

the bright moonshine, enabled me to discover every object round the

meadow-ground, sufficiently well to judge of the position and direction

of the luminous phenomena, the display of which I saw as soon as I had

posted myself at the window. I perceived a number of reddish yellow

flames on different parts of the expanse of almost level ground. I

descried, perhaps, no more than six at a time, but dying away and

appearing in other places so rapidly, that it was impossible to count

them; but I should say, on a rough calculation, there were about twenty

or twenty-five within a second. Some were small and burned dimly;

others flashed with a bright flame, in a direction almost parallel

with the ground, and coinciding with that of the wind, which was

rather brisk. After having for some time looked with amazement at the

brilliant scene, as a whole, I tried to study its details, and soon

found that the flames which were nearest originated in a quagmire, the

position of which I knew exactly, by a solitary cluster of willows;

and I could trace a succession of flashes from that spot to a certain

point of the margin of the wood across the rivulet and meadow. The

distance of the two points from each other was more than half-a-mile,

and the flames travelled over it, perhaps, in less than a second. The

first flash was not always observed in the immediate neighbourhood

of the quagmire; but the succession of flames lay always in the same

straight line, and in the direction of the wind; whilst other sets were

observed, though not with the same distinctness, in the more distant

parts of the meadow-ground.

“After about an hour, a bank of mist began to overspread the meadows,

but I saw the light still glimmering through it, whilst I dressed

myself, in order to examine the phenomenon in its laboratory. However,

when I reached the meadows, the atmospheric conditions which gave rise

to the ignes fatui had ceased to exist.” Weissenborn then expresses his

belief that the phosphoric hydrogen gas, exhaled by certain swamps,

is kindled into flame by coming in contact with the atmospheric air;

but, as the hydrogen is not saturated with phosphorus, (the greater

portion of the latter being precipitated in passing through the water

as red oxide of phosphorus,) there is a certain electric condition

of the atmosphere necessary to cause the combustion. Thus, under

common circumstances, the gas is evolved and dissipated without being

observed; but when the state of the atmosphere is competent to effect

its combustion, the proper degree of electrical tension is lost at

the place where the explosion is effected; and, until it is restored,

or the gas comes in contact with that layer of the atmosphere which

possesses the requisite degree of electrical tension, a considerable

body of bog gas may collect, and be carried in the direction of the

wind, so as to give rise to a sort of quick fire, with occasional

flashes; in those places of the stream of gas where there happens to be

a considerable volume of it. The lights, which still frequently excite

apprehensions in Wales, and are popularly termed “corpse candles,” have

the same origin as the “ignes fatui.”

At the village of Wigmore, in Herefordshire, there are fields which

may be, and two houses which really are, illuminated with a natural

gas. This vapour, with which the subjacent strata seem to be charged,

is obtained in the following manner:--a hole is made in the cellar of

the house, or other locality, with an iron rod; a hollow tube is then

placed therein, fitted with a burner similar to those used for ordinary

gas-lights, and immediately on applying a flame to the jet, a soft and

brilliant light is obtained, which may be kept burning at pleasure. The

gas is very pure, quite free from any offensive smell, and does not

stain the ceilings, as is generally the case with the manufactured

article. Besides lighting rooms, etc., it has been used for cooking;

and, indeed, seems capable of the same applications as prepared

carburetted hydrogen. There are several fields in which the phenomenon

exists, and children are seen boring holes and setting the gas on fire

for amusement. It is now several months since the discovery was made;

and a great many of the curious have visited, and still continue to

visit, the spot.

If the Chinese are not manufacturers, they are, nevertheless, gas

consumers and employers on a large scale; and have evidently been so,

ages before the knowledge of its application was acquired by Europeans.

Beds of coal are frequently pierced by the borers of salt water; and

the inflammable gas is forced up in jets twenty or thirty feet in

height. From these fountains, the vapour has been conveyed to the

salt-works in pipes, and there used for the boiling and evaporation of

the salt; other tubes convey the gas intended for lighting the streets,

and the larger apartments and kitchens. As there is still more gas

than is required, the excess is conducted beyond the limits of the

salt-works, and forms separate chimneys or columns of flame.

A singular counterpart to this employment of natural gas, is witnessed

in the valley of the Kanawha, in Virginia. The origin, the means of

supply, the application to all the processes of manufacturing salt, and

of the appropriation of the surplus for the purposes of illumination,

are remarkably alike at such distant points as China and the United

States.

It has sometimes been stated of a departed person, that a luminous

appearance was observed to rest upon, and occasionally to surround, a

corpse. Such an effect has been described as supernatural--a Divine

attestation to extraordinary excellence; and, doubtless, Roman

Catholics have made the most of such circumstances in reference to

those whom they have denominated saints, and to whom a place has been

assigned in their calendar. And yet there was no departure in any such

instance from the ordinary laws of nature. Sir H. Marsh, in an essay on

“The Evolution of Light from the Human Subject,” states, that electric

sparks have been known to issue from the skin of some individuals

when rubbed lightly and quickly with a linen cloth. Not only has this

physician heard of such cases, but two had actually come under his

observation.

He was led to consider the subject by the following statement made to

him. “About an hour and-a-half before my sister’s death, we were struck

by appearances proceeding from her head, in a diagonal direction. She

was, at the time, in a half-recumbent position, and perfectly tranquil.

The light was pale as the moon, but quite evident to mamma, myself,

and sisters, who were watching over her at the time. One of us, at

first, thought that it was lightning; till, shortly after, we fancied

we perceived a sort of tremulous glimmer playing round the head of the

bed; and then, recollecting that we had read something of a similar

nature having been observed previous to dissolution, we had candles

brought into the room, fearing our dear sister would perceive it, and

that it might disturb the tranquillity of her last moments.”

A similar appearance around the person, and in the room, of a man who

fell a sacrifice to lingering disease in a remote district of the

south-west of Ireland, is recorded. All the witnesses agree in having

seen the light; many, however, came to the conclusion that it was

caused by supernatural agency, and a proof of miraculous interposition,

and even evidence of Divine favour. Considerable excitement was

occasioned in the south of Ireland by the following case, related by

Dr. D. Donavan, in the _Dublin Medical Press_, Jan. 15, 1840:--“I was

sent for,” the Doctor says, “in December, 1828, to see Harrington.

He had been under the care of my predecessor, and had been entered

in the dispensary book as a phthisical patient; and, on reference to

my note-book, I find that the stethoscopic and other indications of

phthisis were indubitable. He was under my care for about five years;

during which time, strange to say, the symptoms continued stationary;

and I had discontinued my attendance for about two years, when the

report became general, that mysterious lights were every night seen in

his cabin. The subject attracted a great deal of attention; and, like

everything else in Ireland, at once assumed a sectarian complexion;

some attributing the light to the miraculous interference of Heaven;

others, to the practice of the black art. Not regarding these views as

affording an explanation of the mystery, I determined to subject the

matter to the ordeal of my own senses; and, for this purpose, visited

the cabin for fourteen nights; and on three nights, only, did I witness

anything unusual. Once I perceived a luminous fog, resembling the

aurora borealis, and twice I saw the scintillations, like the sparkling

phosphorescence sometimes exhibited by the sea infusoria. From the

close scrutiny I made, I can, with certainty, say, that no imposition

was either employed or attempted. How are these appearances to be

accounted for? In answering this question, I would observe, that they

are never seen but in cases of extensive disease, and when considerable

alteration of structure has taken place. Processes analogous to

decomposition are witnessed in the human subject while the living

principle remains.”

On these, and similar facts, Dr. Marsh remarks: “Disease is but a

step toward dissolution, in which the vital powers are impaired; and,

unless the malady be checked, by the use of proper means, a period

will quickly approach when the chemical action will entirely prevail

over the whole frame. Phosphorescent matter may be generated in

organic bodies at a period of incipient decomposition; and when we

consider that phosphuretted hydrogen undergoes spontaneous combustion,

when brought in contact with the oxygen of the atmosphere, and that

the component parts of which this gas is formed exist in the body

in great abundance, an easy solution is at hand, accounting for the

luminous appearances which have been witnessed in dissecting-rooms, in

burial-grounds, and in marine substances, as well as on the approach of

dissolution.”

The Arabs are well known as believers in wonders; and of one of their

magicians, named Sadoomeh, the following story is told. “In order to

give one of his friends a treat, he took him to the distance of about

half-an-hour’s walk into the desert, on the north of Cairo, where

they both sat down upon the pebbly and sandy plain; and the magician

having uttered a spell, they suddenly found themselves in the midst of

a garden, like one of the gardens of Paradise, abounding with flowers

and fruit-trees of every kind, springing up from a soil covered with

verdure brilliant as the emerald, and irrigated by numerous streamlets

of the purest water. A repast of the most delicious viands and fruit

was spread before them by invisible hands; and they both ate and drank

to satiety, taking copious draughts of the various wines. At length

the magician’s guest sank into a deep sleep, and when he awoke he

found himself again in the pebbly and sandy plain, with Sadoomeh still

by his side.” “The reader will probably attribute this vision,” says

Mr. Lane, who relates the tale, “to a dose of opium or some similar

drug; and such I suppose to have been the means employed; for I cannot

doubt the integrity of the narrator, though he would not admit such

an explanation; regarding the whole as an affair of magic, ‘jinn,’ or

genii.”

A story of Gassendi, one of the most distinguished of naturalists,

mathematicians, and philosophers of France, in the sixteenth century,

will place this solution in a still clearer light. As he was taking

a morning walk near Deigne, in Provence, his ears were assailed by

repeated exclamations of “A sorcerer! a sorcerer!” On glancing behind

him, he beheld a mean and simple-looking man, with his hands tied,

whom a mob of the country-people were hurrying to prison. Gassendi’s

character and learning had given him great authority with them, and he

desired to be left alone with the man. They immediately surrendered

him, and Gassendi said to him, in private, “My friend, you must tell

me sincerely, whether you have made a compact with the devil or not:

if you confess it, I will give you your liberty immediately; but, if

you refuse to tell me, I will give you immediately into the hands of a

magistrate.” The man answered, “Sir, I will own that I go to a meeting

of wizards every day. One of my friends has given me a drug, which I

take to effect this, and I have been received as a sorcerer these three

years.” He then described the proceedings of these meetings, and spoke

of the different devils, as if he had been all his life acquainted

with them. “Show me,” said Gassendi, “the drug which you take to attend

this infernal meeting, for I intend to go there with you to-night.”

The man replied, “As you please, Sir; I will take you at midnight, as

soon as the clock strikes twelve.” Accordingly, he met Gassendi at the

appointed hour, and, showing him two boluses, each of the size of a

walnut, he desired him to swallow one, as soon as Gassendi had seen him

swallow the other, and then they lay down together on a goat-skin. The

man soon fell asleep, but Gassendi remained awake and watched him, and

perceived that he was greatly disturbed in his slumbers, and writhed

and twisted his body about, as if he had been troubled by bad dreams.

At the expiration of five or six hours he awoke, and said to Gassendi,

“I am sure, Sir, you ought to be satisfied with the manner in which

the great goat received you; he conferred on you a high honour when

he permitted you to kiss his tail the first time he ever saw you.” It

was thus apparent that the deleterious opiate had operated upon his

imagination. Gassendi, compassionating his weakness and credulity,

took pains to convince him of his self-delusion; and, showing him

the bolus, he gave it to a dog, who soon fell asleep, and suffered

great convulsions. The poor fellow was set at liberty to undeceive

his brethren, who had, like him, been lulled by the noxious drug into

imagining themselves sorcerers.

In India there is a native plant, which, after it has flowered, is

dried and sold in the bazaars of Calcutta, for smoking. The Hindoos

call it “ganpah,” and they give the name of “bang” or “subjee” to

the large leaves and capsules which they use for the same purpose.

The plant is a species of hemp; the smoking of which is considered

so delightful, according to Dr. Thomson, as to have been denominated

by such epithets as “Assuager of sorrow,” “Increaser of pleasure,”

“Cementer of friendship,” “Laughter-mover,” and others of the same kind.

On the same authority it is stated, that in Nepaul, the resin only

is used; in some places it is collected by native coolies, walking

through the fields of hemp at the time the plants give forth the resin,

which, adhering to the skin, is scraped off from it, and kneaded into

balls. It is taken in doses, from a grain to two grains, and causes

a delightful delirium. When repeated, however, it is followed by

catalepsy, or that state of insensibility which allows the body to be

moulded into any form like a Dutch-jointed doll, the limbs remaining in

the position in which they were placed, though contrary to the law of

gravity, and continuing so for many hours.

We are well acquainted with various means of acting in an extraordinary

manner on the human frame. The writer, in common with multitudes, has

witnessed, for example, the operation of nitrous oxide, often called

“the laughing-gas.” It acts, however, very differently on different

persons; some laugh immoderately, others become depressed, others

assume the airs of vanity and importance which accord with their most

cherished dispositions; and some can only be forcibly restrained from

deeds of great violence. It is certainly a most singular sight to see

a person laughing most boisterously, or strutting with all the hauteur

of a newly-made potentate, suddenly subside as the action of the gas

ceases, into a very unobtrusive individual.

We may now briefly allude to one of the most extraordinary applications

of the present times. The late sir Humphry Davy made many experiments

on the effects of various gases on the human lungs. He found, in his

own person, that the inhalation of nitrous oxide removed head-ache,

and greatly assuaged the pain of cutting a wisdom-tooth. In his works,

edited by Dr. John Davy, is the following passage:--

“As nitrous oxide, in its extensive operation, appears capable of

destroying physical pain, it may probably be used with advantage during

surgical operations in which no great effusion of blood takes place.”

Here is the germ of the recent application of ether.

“The effects of this inhalation, as indicated by the patient’s own

recollection,” says a writer in the _North British Review_, “are very

various. In general they are somewhat as follows:--A pleasing sense

of soothing succeeds the first irksomeness of the pungent vapour--a

soothing of both mind and body. Ringing in the ears takes place, with

some confusion of sight and intellectual perception. The limbs are

felt cold and powerless; the hands and feet first, then the knees;

and the feeling is as if these parts had ceased to be peculiar

property, and dropped away. This sensation may gradually creep over

the whole frame; the patient becoming, in more senses than one, truly

etherealized; reduced to the condition of no body and all soul. The

objects around are either lost sight of or strangely perverted; fancied

shadows flit before the eyes, and then a dream sets in--sometimes calm

and placid, sometimes active and bustling, sometimes very pleasurable,

sometimes frightful, as a nightmare. Emerging, the figures and scenes

shift rapidly, and grow fainter and fainter; present objects are

caught by the eye once more, the ringing of the ears is heard again,

consciousness and self-control return, a tendency to excited talking is

very manifest, movement is unsteady, and, both in mind and body, a kind

of intoxication is declared. It is, however, of a light and airy kind;

very pure, very pleasant, and very passing, and, when gone, leaving

very little trace behind.

“Experience has fully shown that the brain may be acted on so as to

annihilate, for the time, what may be termed the faculty of feeling

pain; the organ of general sense may be lulled into profound sleep,

while the organ of special sense, and the organ of intellectual

function remain wide awake, active, and busily employed. The patient

may feel no pain under very cruel cutting, and yet he may see,

hear, taste, and smell, as well as ever, to all appearance; and he

may also be perfectly conscious of everything within reach of his

observation--able to reason on such events most lucidly, and able to

retain both the events and the reasoning in his memory afterwards.

We have seen a patient following the operator with her eyes most

intelligently and watchfully, as he shifted his place near her, lifted

his knife, and proceeded to use it; wincing not at all during its use;

answering questions by gesture, very readily and plainly; and, after

the operation was over, narrating every event as it occurred; declaring

that she knew and saw all; stating that she knew and felt that she was

being cut, and yet that she felt no pain whatever. Patients have said,

quietly, ‘You are sawing now,’ during the use of the saw in amputation;

and afterwards they have declared most solemnly, that though quite

conscious of that part of the operation, yet they felt no pain. We

have seen a patient enduring amputation of a limb without any sign

of suffering, opening her eyes during the performance, at its most

painful part, descrying a country practitioner at some distance--under

whose care she had formerly been, and whom she had not seen for some

considerable time--addressing him by name, and requesting that he might

not leave town without seeing her.”

Since the period to which the writer just quoted refers, Dr.

Simpson, of Edinburgh, has discovered a substitute for sulphuric

ether--chloroform, or the perchloride of formyle. It is stated to

possess over sulphuric ether the following advantages:--1. A greatly

less quantity of chloroform than of ether is requisite to produce the

desired effect. 2. Its action is much more rapid and complete, and

generally more enduring. 3. The inhalation and influence of chloroform

are far more agreeable and pleasant than those of ether. 4. The use

of chloroform is less expensive than that of ether. 5. Its odour is

not unpleasant; nor does it exhale in a disagreeable form from the

lungs of the patient, as so generally happens with sulphuric ether.

6. Being required in much less quantity, it is much more portable and

transmissible than sulphuric ether. 7. No special kind of inhaler

or instrument is necessary for its exhibition. A little of the

liquid diffused upon the interior of a hollow-shaped sponge, or on a

pocket-handkerchief, or a piece of linen or paper, or held over the

mouth and nostrils, so as to be fully inhaled, generally suffices, in

about a minute or two, to produce the effect. This agent, however,

requires to be used to annul pain under the direction of a judicious

medical practitioner; it may otherwise be productive of serious

consequences.

A prodigious force often arises from chemical affinity. Of this,

gunpowder presents a familiar instance. It is formed of nitre,

sulphur, and charcoal, which, in the ordinary state, are only combined

mechanically; but no sooner is this compound ignited, than these

substances are brought, by chemical action, into such close contact,

as to evolve a mighty and destructive power. It seemed likely to be

thrown into the shade by the discovery of gun-cotton as an explosive

agent, which excited extraordinary interest throughout Europe. On

projectile experiments being made, a gun, charged with thirty grains

of prepared cotton, propelled an equal charge of shot, with greater

force and precision, at a distance of forty yards, than were gained

by the same gun loaded with a hundred-and-twenty grains of gunpowder.

A rifle, charged with fifty-four and-a-half grains of gunpowder,

sent a ball through seven boards, half-an-inch in thickness, at a

distance of forty yards; the same rifle, charged with forty grains of

gun-cotton, caused the ball to enter the eighth board. Another rifle,

which had been used for elephant-shooting, and consequently carried a

much larger ball, charged with forty grains of gun-cotton, forced the

ball through eight boards, at a distance of ninety yards. In no case

was the discharge accompanied by a greater recoil than usual; and the

reports were not louder than those accompanying the discharge of guns

and rifles loaded with gunpowder. According to the specification of the

patentee, M. Schönbein, cotton is preferred for this purpose, freed

from extraneous matters; and it is considered desirable to operate on

the clean fibres of the cotton in a dry state, by means of nitric and

sulphuric acids. These are mixed together in the proportion of one

measure of nitric acid to three measures of sulphuric acid, in any

suitable or convenient vessel not liable to be affected by the acids.

A great degree of heat being generated by the mixture, it is left to

cool until its temperature falls to sixty or fifty degrees Fahrenheit.

The cotton is then immersed in it; and, in order that it may become

thoroughly saturated with the acids, it is stirred with a rod of glass,

or other material, not affected by the acids. The cotton should be

introduced in as open a state as practicable. The acids are then poured

or drawn off, and the cotton gently pressed by a presser of glazed

earthenware, to take out the acids, after which it is covered up in

the vessel, and allowed to stand for about an hour. It is subsequently

washed in a continuous flow of water, until the presence of the acids

is not indicated by the ordinary test of litmus paper. To remove any

uncombined portions of the acids which may remain after the cleansing

process, the patentee dips the cotton in a weak solution of carbonate

of potash, composed of one ounce of carbonate of potash to one gallon

of water, and partially dries it by pressing, as before. The cotton is

then highly explosive, and may be used in that state; but, to increase

its explosive power, it is dipped in a weak solution of nitrate of

potash, and, lastly, dried in a room heated by hot air, or steam, to

about one hundred and fifty degrees Fahrenheit.

The advantages and disadvantages of this substance have thus been

stated by professor Brande:--“The disadvantages are, that the effects

are less regular than those of gunpowder; that it is more dangerous,

because inflaming at a lower temperature; that it does not take

fire when compressed in tubes; that it burns slowly in all kinds of

cartridges; that guns and pistols must be altered to admit of its

use; that it is not adapted for the use of the army; that the barrel

of the gun is moistened by the water produced during combustion. The

advantages, on the other hand, may be stated as follows:--Its extreme

cleanliness, leaving no residue after combustion; its freedom from

all bad smell; the facility and the safety of its preparation; the

possessing treble the force of gunpowder; its explosion producing

no smoke, and less noise than that of gunpowder; its filamentary

nature admitting of its being used over head in mining operations;

its not being liable (as a granulated substance is) to the accidents

of leakage; its occasioning very little recoil.”--Every benevolent

mind must wish to hear no more of “the confused noise of battle and

of garments rolled in blood;” and that the time may soon arrive when

men shall “beat their swords into ploughshares, and their spears

into pruning-hooks;” when “they shall learn war no more,” but yield

themselves heartily and devotedly to the benignant sway of the Prince

of peace. There seems, however, no reason to conclude that gun-cotton

will be employed for any hostile purpose, the Board of Ordnance having

definitely decided against its adoption in the military and naval

services. The principal objection to it is, the very low temperature at

which it explodes. The mere heating of a gun, from a number of charges

successively fired, has been proved sufficient to cause an instant

explosion of gun-cotton.

In mining, it is likely to be of great use. In the slate-quarries at

Penrhyns it has been found far superior to gunpowder. A huge mass of

sixty tons’ weight, for instance, was gently pushed from its firmly

compacted bed by the explosion of only eight ounces of cotton, while

the slate was not splintered. In other great works it will also be of

service. In a cutting on the Syston and Peterborough railway, not far

from Stamford, experiments showed the average powers of the gun-cotton

to be in the proportion of one to six of gunpowder; so that, in a hard

freestone foundation, about five feet thick, and with an entire depth

of twenty-eight feet, where six holes were necessary for gunpowder,

only one was required for gun-cotton. In all blasting operations,

whether in open cuttings, tunnels, or deep mines, a great saving of

time, labour, and cost, is thus likely to be effected.

Magic, Pretended Miracles, and Remarkable Natural Phenomena · 第 5 / 11 章