The mind of Mr. Bagges was decidedly affected—beneficially—by the
lecture on the Chemistry of a Candle, which, as set forth in a previous
number of this journal, had been delivered to him by his youthful
nephew. That learned discourse inspired him with a new feeling; an
interest in matters of science. He began to frequent the Polytechnic
Institution, nearly as much as his club. He also took to lounging at the
British Museum; where he was often to be seen, with his left arm under
his coat-tails, examining the wonderful works of nature and antiquity,
through his eye-glass. Moreover, he procured himself to be elected a
member of the Royal Institution, which became a regular house of call to
him, so that in a short time he grew to be one of the ordinary phenomena
of the place.
Mr. Bagges likewise adopted a custom of giving _conversaziones_, which,
however, were always very private and select—generally confined to his
sister’s family. Three courses were first discussed; then dessert; after
which, surrounded by an apparatus of glasses and decanters, Master Harry
Wilkinson was called upon, as a sort of juvenile Davy, to amuse his
uncle by the elucidation of some chemical or other physical mystery.
Master Wilkinson had now attained to the ability of making experiments;
most of which, involving combustion, were strongly deprecated by the
young gentleman’s mamma; but her opposition was overruled by Mr. Bagges,
who argued that it was much better that a young dog should burn
phosphorus before your face than let off gunpowder behind your back, to
say nothing of occasionally pinning a cracker to your skirts. He
maintained that playing with fire and water, throwing stones, and such
like boys’ tricks, as they are commonly called, are the first
expressions of a scientific tendency—endeavours and efforts of the
infant mind to acquaint itself with the powers of Nature.
His own favourite toys, he remembered, were squibs, suckers, squirts,
and slings; and he was persuaded that, by his having been denied them at
school, a natural philosopher had been nipped in the bud.
Blowing bubbles was an example—by-the-bye, a rather notable one—by which
Mr. Bagges, on one of his scientific evenings, was instancing the
affinity of child’s play to philosophical experiments, when he bethought
him Harry had said on a former occasion that the human breath consists
chiefly of carbonic acid, which is heavier than common air. How then, it
occurred to his inquiring, though elderly mind, was it that
soap-bladders, blown from a tobacco-pipe, rose instead of sinking? He
asked his nephew this.
“Oh, uncle!” answered Harry, “in the first place, the air you blow
bubbles with mostly comes in at the nose and goes out at the mouth,
without having been breathed at all. Then it is warmed by the mouth, and
warmth, you know, makes a measure of air get larger, and so lighter in
proportion. A soap-bubble rises for the same reason that a fire-balloon
rises—that is, because the air inside of it has been heated, and weighs
less than the same sized bubbleful of cold air.”
“What, hot breath does!” said Mr. Bagges. “Well, now, it’s a curious
thing, when you come to think of it, that the breath should be
hot—indeed, the warmth of the body generally seems a puzzle. It is
wonderful, too, how the bodily heat can be kept up so long as it is.
Here, now, is this tumbler of hot grog—a mixture of boiling water, and
what d’ye call it, you scientific geniuses?”
“Alcohol, uncle.”
“Alcohol—well—or, as we used to say, brandy. Now, if I leave this
tumbler of brandy-and-water alone——”
“_If_ you do, uncle,” interposed his nephew, archly.
“Get along, you idle rogue! If I let that tumbler stand there, in a few
minutes the brandy-and water—eh?—I beg pardon—the alcohol-and-water—gets
cold. Now, why—why the deuce—if the brandy—the alcohol-and-water cools;
why—how—how is it we don’t cool in the same way, I want to know? eh?”
demanded Mr. Bagges, with the air of a man who feels satisfied that he
has propounded a “regular poser.”
“Why,” replied Harry, “for the same reason that the room keeps warm so
long as there is a fire in the grate.”
“You don’t mean to say that I have a fire in my body?”
“I do, though.”
“Eh, now? That’s good,” said Mr. Bagges. “That reminds me of the man in
love crying, ‘Fire! fire!’ and the lady said, ‘Where, where?’ And he
called out, ‘Here! here!’ with his hand upon his heart. Eh?—but now I
think of it—you said, the other day, that breathing was a sort of
burning. Do you mean to tell me that I—eh?—have fire, fire, as the lover
said, here, here—in short, that my chest is a grate or an Arnott’s
stove?”
“Not exactly so, uncle. But I do mean to tell you that you have a sort
of fire burning partly in your chest; but also, more or less, throughout
your whole body.”
“Oh, Henry!” exclaimed Mrs. Wilkinson, “How can you say such horrid
things!”
“Because they’re quite true, mamma—but you needn’t be frightened. The
fire of one’s body is not hotter than from ninety degrees to one hundred
and four degrees or so. Still it is fire, and will burn some things, as
you would find, uncle, if, in using phosphorus, you were to let a little
bit of it get under your nail.”
“I’ll take your word for the fact, my boy,” said Mr. Bagges. “But, if I
have a fire burning throughout my person—which I was not aware of, the
only inflammation I am ever troubled with being in the great toe—I say,
if my body is burning continually—how is it I don’t smoke—eh? Come,
now!”
“Perhaps you consume your own smoke,” suggested Mr. Wilkinson, senior,
“like every well-regulated furnace.”
“You smoke nothing but your pipe, uncle, because you burn all your
carbon,” said Harry. “But, if your body doesn’t smoke, it steams.
Breathe against a looking-glass, or look at your breath on a cold
morning. Observe how a horse reeks when it perspires. Besides—as you
just now said you recollected my telling you the other day—you breathe
out carbonic acid, and that, and the steam of the breath together, are
exactly the same things, you know, that a candle turns into in burning.”
“But if I burn like a candle—why don’t I burn _out_ like a candle?”
demanded Mr. Bagges. “How do you get over that?”
“Because,” replied Harry, “your fuel is renewed as fast as burnt. So
perhaps you resemble a lamp rather than a candle. A lamp requires to be
fed; so does the body—as, possibly, uncle, you may be aware.”
“Eh?—well—I have always entertained an idea of that sort,” answered Mr.
Bagges, helping himself to some biscuits. “But the lamp feeds on
train-oil.”
“So does the Laplander. And you couldn’t feed the lamp on turtle or
mulligatawny, of course, uncle. But mulligatawny or turtle can be
changed into fat—they are so, sometimes, I think—when they are eaten in
large quantities, and fat will burn fast enough. And most of what you
eat turns into something which burns at last, and is consumed in the
fire that warms you all over.”
“Wonderful, to be sure,” exclaimed Mr. Bagges. “Well, now, and how does
this extraordinary process take place?”
“First, you know, uncle, your food is digested—”
“Not always, I am sorry to say, my boy,” Mr. Bagges observed, “but go
on.”
“Well; when it _is_ digested, it becomes a sort of fluid, and mixes
gradually with the blood, and turns into blood, and so goes over the
whole body, to nourish it. Now, if the body is always being nourished,
why doesn’t it keep getting bigger and bigger, like the ghost in the
Castle of Otranto?”
“Eh? Why, because it loses as well as gains, I suppose. By
perspiration—eh—for instance?”
“Yes, and by breathing; in short, by the burning I mentioned just now.
Respiration, or breathing, uncle, is a perpetual combustion.”
“But if my system,” said Mr. Bagges, “is burning throughout, what keeps
up the fire in my little finger—putting gout out of the question?”
“You burn all over, because you breathe all over, to the very tips of
your fingers’ ends,” replied Harry.
“Oh, don’t talk nonsense to your uncle!” exclaimed Mrs. Wilkinson.
“It isn’t nonsense,” said Harry. “The air that you draw into the lungs
goes more or less over all the body, and penetrates into every fibre of
it, which is breathing. Perhaps you would like to hear a little more
about the chemistry of breathing, or respiration, uncle?”
“I should, certainly.”
“Well, then; first you ought to have some idea of the breathing
apparatus. The laboratory that contains this, is the chest, you know.
The chest, you also know, has in it the heart and lungs, which, with
other things in it, fill it quite out, so as to leave no hollow space
between themselves and it. The lungs are a sort of air-sponges, and when
you enlarge your chest to draw breath, they swell out with it and suck
the air in. On the other hand you narrow your chest and squeeze the
lungs and press the air from them;—that is breathing out. The lungs are
made up of a lot of little cells. A small pipe—a little branch of the
windpipe—opens into each cell. Two blood-vessels, a little tiny artery,
and a vein to match, run into it also. The arteries bring into the
little cells dark-coloured blood, which _has been_ all over the body.
The veins carry out of the little cells bright scarlet-coloured blood,
which _is to go_ all over the body. So all the blood passes through the
lungs, and in so doing, is changed from dark to bright scarlet.”
“Black blood, didn’t you say, in the arteries, and scarlet in the veins?
I thought it was just the reverse,” interrupted Mr. Bagges.
“So it is,” replied Harry, “with all the other arteries and veins,
except those that circulate the blood through the lung-cells. The heart
has two sides, with a partition between them that keeps the blood on the
right side separate from the blood on the left; both sides being hollow,
mind. The blood on the right side of the heart comes there from all over
the body, by a couple of large veins, dark, before it goes to the lungs.
From the right side of the heart, it goes on to the lungs, dark still,
through an artery. It comes back to the left side of the heart from the
lungs, bright scarlet, through four veins. Then it goes all over the
rest of the body from the left side of the heart, through an artery that
branches into smaller arteries, all carrying bright scarlet blood. So
the arteries and veins of the lungs on one hand, and of the rest of the
body on the other, do exactly opposite work, you understand.”
“I hope so.”
“Now,” continued Harry, “it requires a strong magnifying glass to see
the lung-cells plainly, they are so small. But you can fancy them as big
as you please. Picture any one of them to yourself of the size of an
orange, say, for convenience in thinking about it; that one cell, with
whatever takes place in it, will be a specimen of the rest. Then you
have to imagine an artery carrying blood of one colour into it, and a
vein taking away blood of another colour from it, and the blood changing
its colour in the cell.”
“Aye, but what makes the blood change its colour?”
“Recollect, uncle, you have a little branch from the windpipe opening
into the cell which lets in the air. Then the blood and the air are
brought together, and the blood alters in colour. The reason, I suppose
you would guess, is that it is somehow altered by the air.”
“No very unreasonable conjecture, I should think,” said Mr. Bagges.
“Well; if the air alters the blood, most likely, we should think, it
gives something to the blood. So first let us see what is the difference
between the air we breathe _in_, and the air we breathe _out_. You know
that neither we nor animals can keep breathing the same air over and
over again. You don’t want me to remind you of the Black Hole of
Calcutta, to convince you of that; and I dare say you will believe what
I tell you, without waiting till I can catch a mouse and shut it up in
an air-tight jar, and show you how soon the unlucky creature will get
uncomfortable, and begin to gasp, and that it will by-and-by die. But if
we were to try this experiment—not having the fear of the Society for
the Prevention of Cruelty to Animals, nor the fear of doing wrong,
before our eyes—we should find that the poor mouse, before he died, had
changed the air of his prison considerably. But it would be just as
satisfactory, and much more humane, if you or I were to breathe in and
out of a silk bag or a bladder till we could stand it no longer, and
then collect the air which we had been breathing in and out. We should
find that a jar of such air would put out a candle. If we shook some
lime-water up with it, the lime-water would turn milky. In short, uncle,
we should find that a great part of the air was carbonic acid, and the
rest mostly nitrogen. The air we inhale is nitrogen and oxygen; the air
we exhale has lost most of its oxygen, and consists of little more than
nitrogen and carbonic acid. Together with this, we breathe out the
vapour of water, as I said before. Therefore in breathing, we give off
exactly what a candle does in burning, only not so fast, after the rate.
The carbonic acid we breathe out, shows that carbon is consumed within
our bodies. The watery vapour of the breath is a proof that hydrogen is
so too. We take in oxygen with the air, and the oxygen unites with
carbon, and makes carbonic acid, and with hydrogen, forms water.”
“Then don’t the hydrogen and carbon combine with the oxygen—that is,
burn—in the lungs, and isn’t the chest the fireplace, after all?” asked
Mr. Bagges.
“Not altogether, according to those who are supposed to know better.
They are of opinion, that some of the oxygen unites with the carbon and
hydrogen of the blood in the lungs; but that most of it is merely
absorbed by the blood, and dissolved in it in the first instance.”
“Oxygen absorbed by the blood? That seems odd,” remarked Mr. Bagges,
“How can that be?”
“We only know the fact that there are some things that will absorb
gases—suck them in—make them disappear. Charcoal will, for instance. It
is thought that the iron which the blood contains gives it the curious
property of absorbing oxygen. Well; the oxygen going into the blood
makes it change from dark to bright scarlet; and then this blood
containing oxygen is conveyed all over the system by the arteries, and
yields up the oxygen to combine with hydrogen and carbon as it goes
along. The carbon and hydrogen are part of the substance of the body.
The bright scarlet blood mixes oxygen with them, which burns them, in
fact; that is, makes them into carbonic acid and water. Of course, the
body would soon be consumed if this were all that the blood does. But
while it mixes oxygen with the old substance of the body, to burn it up,
it lays down fresh material to replace the loss. So our bodies are
continually changing throughout, though they seem to us always the same;
but then, you know, a river appears the same from year’s end to year’s
end, although the water in it is different every day.”
“Eh, then,” said Mr. Bagges, “if the body is always on the change in
this way, we must have had several bodies in the course of our lives, by
the time we are old.”
“Yes, uncle; therefore, how foolish it is to spend money upon funerals.
What becomes of all the bodies we use up during our lifetimes? If we are
none the worse for their flying away in carbonic acid and other things
without ceremony, what good can we expect from having a fuss made about
the body we leave behind us, which is put into the earth? However, you
are wanting to know what becomes of the water and carbonic acid which
have been made by the oxygen of the blood burning up the old materials
of our frame. The dark blood of the veins absorbs this carbonic acid and
water, as the blood of the arteries does oxygen,—only, they say, it does
so by means of a salt in it, called phosphate of soda. Then the dark
blood goes back to the lungs, and in them it parts with its carbonic
acid and water, which escapes as breath. As fast as we breathe out,
carbonic acid and water leave the blood; as fast as we breathe in,
oxygen enters it. The oxygen is sent out in the arteries to make the
rubbish of the body into gas and vapour, so that the veins may bring it
back and get rid of it. The burning of rubbish by oxygen throughout our
frames is the fire by which our animal heat is kept up. At least this is
what most philosophers think; though doctors differ a little on this
point, as on most others, I hear. Professor Liebig says, that our carbon
is mostly prepared for burning by being first extracted from the blood
sent to it—(which contains much of the rubbish of the system
dissolved)—in the form of bile, and is then re-absorbed into the blood,
and burnt. He reckons that a grown-up man consumes about fourteen ounces
of carbon a day. Fourteen ounces of charcoal a day, or eight pounds two
ounces a week, would keep up a tolerable fire.”
“I had no idea we were such extensive charcoal-burners,” said Mr.
Bagges. “They say we each eat our peck of dirt before we die—but we must
burn bushels of charcoal.”
“And so,” continued Harry, “the Professor calculates that we burn quite
enough fuel to account for our heat. I should rather think, myself, it
had something to do with it—shouldn’t you?”
“Eh?” said Mr. Bagges; “it makes one rather nervous to think that one is
burning all over—throughout one’s very blood—in this kind of way.”
“It is very awful!” said Mrs. Wilkinson.
“If true. But in that case, shouldn’t we be liable to inflame
occasionally?” objected her husband.
“It is said,” answered Harry, “that spontaneous combustion does happen
sometimes; particularly in great spirit drinkers. I don’t see why it
should not, if the system were to become too inflammable. Drinking
alcohol would be likely to load the constitution with carbon, which
would be fuel for the fire, at any rate.”
“The deuce!” exclaimed Mr. Bagges, pushing his brandy-and-water from
him. “We had better take care how we indulge in combustibles.”
“At all events,” said Harry, “it must be bad to have too much fuel in
us. It must choke the fire I should think, if it did not cause
inflammation; which Dr. Truepenny says it does, meaning, by
inflammation, gout, and so on, you know, uncle.”
“Ahem!” coughed Mr. Bagges.
“Taking in too much fuel, I dare say you know, uncle, means eating and
drinking to excess,” continued Harry. “The best remedy, the doctor says,
for overstuffing is exercise. A person who uses great bodily exertion,
can eat and drink more without suffering from it than one who leads an
inactive life; a foxhunter, for instance, in comparison with an
alderman. Want of exercise and too much nourishment must make a man
either fat or ill. If the extra hydrogen and carbon are not burnt out,
or otherwise got rid of, they turn to blubber, or cause some disturbance
in the system, intended by Nature to throw them off, which is called a
disease. Walking, riding, running, increase the breathing—as well as the
perspiration—and make us burn away our carbon and hydrogen in
proportion. Dr. Truepenny declares that if people would only take in as
much fuel as is requisite to keep up a good fire, his profession would
be ruined.”
“The good old advice—Baillie’s, eh?—or Abernethy’s—live upon sixpence a
day, and earn it,” Mr. Bagges observed.
“Well, and then, uncle, in hot weather the appetite is naturally weaker
than it is in cold—less heat is required, and therefore less food. So in
hot climates; and the chief reason, says the doctor, why people ruin
their health in India is their spurring and goading their stomachs to
crave what is not good for them, by spices and the like. Fruits and
vegetables are the proper things to eat in such countries, because they
contain little carbon compared to flesh, and they are the diet of the
natives of those parts of the world. Whereas food with much carbon in
it, meat, or even mere fat or oil, which is hardly anything else than
carbon and hydrogen, are proper in very cold regions, where heat from
within is required to supply the want of it without. That is why the
Laplander is able, as I said he does, to devour train-oil. And Dr.
Truepenny says that it may be all very well for Mr. M‘Gregor to drink
raw whiskey at deer-stalking in the Highlands, but if Major Campbell
combines that beverage with the diversion of tiger-hunting in the East
Indies, habitually, the chances are that the Major will come home with a
diseased liver.”
“Upon my word, sir, the whole art of preserving health appears to
consist in keeping up a moderate fire within us,” observed Mr. Bagges.
“Just so, uncle, according to my friend the Doctor. ‘Adjust the fuel,’
he says, ‘to the draught—he means the oxygen; keep the bellows properly
at work, by exercise, and your fire will seldom want poking.’ The
Doctor’s pokers, you know, are pills, mixtures, leeches, blisters,
lancets, and things of that sort.”
“Indeed? Well, then, my heart-burn, I suppose, depends upon bad
management of my fire?” surmised Mr. Bagges.
“I should say that was more than probable, uncle. Well, now, I think you
see that animal heat can be accounted for, in very great part at least,
by the combustion of the body. And then there are several facts that—as
I remember Shakespeare says—
“‘help to thicken other proofs,
That do demonstrate thinly.’
“Birds that breathe a great deal are very hot creatures; snakes and
lizards, and frogs and fishes, that breathe but little, are so cold that
they are called cold-blooded animals. Bears and dormice, that sleep all
the winter, are cold during their sleep, whilst their breathing and
circulation almost entirely stop. We increase our heat by walking fast,
running, jumping, or working hard; which sets us breathing faster, and
then we get warmer. By these means we blow up our own fire, if we have
no other, to warm ourselves on a cold day. And how is it that we don’t
go on continually getting hotter and hotter?”
“Ah!” exclaimed Mr. Bagges, “I suppose that is one of Nature’s
mysteries.”
“Why, what happens, uncle, when we take violent exercise? We break out
into a perspiration; as you complain you always do, if you only run a
few yards. Perspiration is mostly water, and the extra heat of the body
goes into the water, and flies away with it in steam. Just for the same
reason, you can’t boil water so as to make it hotter than two hundred
and twelve degrees; because all the heat that passes into it beyond
that, unites with some of it and becomes steam, and so escapes. Hot
weather causes you to perspire even when you sit still; and so your heat
is cooled in summer. If you were to heat a man in an oven, the heat of
his body generally wouldn’t increase very much till he became exhausted
and died. Stories are told of mountebanks sitting in ovens, and meat
being cooked by the side of them. Philosophers have done much the same
thing—Dr. Fordyce and others, who found they could bear a heat of two
hundred and sixty degrees. Perspiration is our animal fire-escape. Heat
goes out from the lungs, as well as the skin, in water; so the lungs are
concerned in cooling us as well as heating us, like a sort of regulating
furnace. Ah, uncle, the body is a wonderful factory, and I wish I were
man enough to take you over it. I have only tried to show you something
of the contrivances for warming it, and I hope you understand a little
about that!”
“Well,” said Mr. Bagges, “breathing, I understand you to say, is the
chief source of animal heat, by occasioning the combination of carbon
and hydrogen with oxygen, in a sort of gentle combustion, throughout our
frame. The lungs and heart are an apparatus for generating heat, and
distributing it over the body by means of a kind of warming pipes,
called blood-vessels. Eh?—and the carbon and hydrogen we have in our
systems we get from our food. Now, you see, here is a slice of cake, and
there is a glass of wine—Eh?—now see whether you can get any carbon and
oxygen out of that.”
The young philosopher, having finished his lecture, applied himself
immediately to the performance of the proposed experiment, which he
performed with cleverness and dispatch.