<h2><SPAN name="CHAPTER_XXXVII" id="CHAPTER_XXXVII"></SPAN>CHAPTER XXXVII.</h2>
<hr class="bible-verse" />
<p class="center bq">"Where wast thou when I laid the foundations of
the earth? declare, if thou hast understanding."</p>
<hr class="bible-verse" />
<p><SPAN id="question_792"></SPAN>792. <i>What is repulsion?</i></p>
<p>Repulsion is that property in matter by which it <i>repels</i> or <i>recedes
from</i>, those bodies for which it has <i>no attraction or affinity</i>.</p>
<p><SPAN id="question_793"></SPAN>793. <i>Why does dew form into round drops upon the leaves of plants?</i></p>
<p>Because it <i>repels the air</i>, and the <i>substances of the leaves</i> upon
which it rests. Because, also, its own particles <i>cohere</i>.</p>
<p><SPAN id="question_794"></SPAN>794. <i>Why do drops of water roll over dusty surfaces?</i></p>
<p>Because they <i>repel</i> the particles of dust; and also because their
own particles have <i>a stronger attraction for each other</i> than for
the particles of dust.</p>
<p><SPAN id="question_795"></SPAN>795. <i>Why does a needle float when carefully laid upon the surface of
water?</i></p>
<p>Because the needle and the water <i>mutually repel each other</i>.</p>
<p><SPAN id="question_796"></SPAN>796. <i>Why does water, when dropped upon hot iron, move about in
agitated globules?</i></p>
<p>Because the <i>caloric</i> repels the particles of the water.</p>
<p><SPAN id="question_797"></SPAN>797. <i>Why does oil float upon the surface of water?</i></p>
<p>Because, besides being specially lighter than water, the particles of
the oil and the water <i>mutually repel each other</i>.</p>
<p><SPAN id="question_798"></SPAN>798. <i>What is carbonic acid?</i></p>
<p>Carbonic acid is a mixture of <i>carbon</i> and <i>oxygen</i>, in the
proportion of 3 lbs. of carbon to 8 lbs. of oxygen.</p>
<hr class="bible-verse" />
<p class="center bq">"Who hath laid the measures thereof, if thou
knowest? or who hath stretched the line upon it?"</p>
<hr class="bible-verse" />
<p><SPAN id="question_799"></SPAN>799. <i>Where does carbonic acid chiefly exist?</i></p>
<p><span class="pagenum"><SPAN name="Page_177" id="Page_177">[Pg 177]</SPAN></span></p>
<p>It exists in various natural bodies in which carbon and oxygen are
combined; it is evolved by the decomposition of numerous bodies
called carbonates, in which carbon is united with a particular base,
such as the carbonate of lime, the carbonate of iron, the carbonate
of copper, &c. It is also evolved by the processes of <i>fermentation</i>,
by the <i>breathing of animals</i>, the <i>combustion of fuel</i>, and the
<i>functions of plants</i>. Carbonic acid also <i>exists in various waters</i>.</p>
<p>Carbonic acid is <i>found most largely in solid combinations with other
bodies</i>: it forms 44-100ths of all limestones and marbles, and it
exists in smaller quantity, combined with other earths, and with
metallic oxides.</p>
<p><SPAN id="question_800"></SPAN>800. <i>What are the states in which pure carbonic acid exists?</i></p>
<p>Pure carbonic acid may exist in the <i>solid</i>, the <i>liquid</i>, or
the <i>æriform</i> state. In the <i>solid state</i> it is produced only
by artificial means, and it is then a white crystallised body,
in appearance <i>like snow</i>;
in the <i>liquid state</i> it is a <i>heavy
colourless fluid</i>;
in the <i>æriform state</i> it is a <i>pungent</i>, <i>heavy</i>,
<i>colourless gas</i>, and is known as <i>carbonic acid gas</i>.</p>
<p><SPAN id="question_801"></SPAN>801. <i>Why does bottled porter produce large volumes of froth, much
more than the bottle could contain?</i></p>
<p>Because, by the fermentive process, <i>carbonic acid</i> has been
developed in the porter, and is held in <i>liquid solution</i>;
but it
always has a <i>strong tendency to escape</i>, and directly the pressure
is removed, it <i>evolves into gas</i>, by which it occupies much greater
space, and forces the porter in millions of small bubbles out of the
bottle.</p>
<p><SPAN id="question_802"></SPAN>802. <i>Why does soda-water effervesce?</i></p>
<p>Because <i>carbonic acid gas</i> is forced into the water <i>by pressure</i>.
Pressure <i>alters the gas into a liquid</i>, and directly the pressure
ceases, the liquid again <i>evolves into gas</i>.</p>
<p><SPAN id="question_803"></SPAN>803. <i>Why does spring water taste fresh and invigorating?</i></p>
<p>Because it contains <i>carbonic acid</i>.</p>
<p><span class="pagenum"><SPAN name="Page_178" id="Page_178">[Pg 178]</SPAN></span></p>
<hr class="bible-verse" />
<p class="center bq">"Whereupon are the foundations thereof fastened?
or who laid the cornerstone thereof."—<span class="smcap">Job xxxviii.</span></p>
<hr class="bible-verse" />
<p><SPAN id="question_804"></SPAN>804. <i>Why does boiled water taste flat and insipid?</i></p>
<p>Because the <i>carbonic acid</i> has been <i>driven off</i> by boiling.</p>
<p><SPAN id="question_805"></SPAN>805. <i>Why does beer which has been standing in a glass taste flat?</i></p>
<p>Because its <i>carbonic acid</i> has escaped as <i>carbonic acid gas</i>.</p>
<p><SPAN id="question_806"></SPAN>806. <i>Why, when we look into a glass of champagne, do we see bubbles
spontaneously appear at the bottom, and then rise to the top?</i></p>
<p>Because, in the places where the bubbles are formed, the <i>liquid
carbonic acid</i> is evolving into <i>carbonic acid gas</i>.</p>
<p><SPAN id="question_807"></SPAN>807. <i>Why do the bubbles arise from two or three points in columns,
rapidly succeeding each other?</i></p>
<p>Because, when the formation of gas once begins, and bubbles ascend,
there is <i>less pressure</i> in the line of the <i>column of bubbles</i>;
the
carbonic acid, therefore, draws towards those points as the <i>easiest
channel of escape</i>.</p>
<p class="bq">These explanations equally apply to the "working" of beer, by
which yeast is produced; to the effervescence of various waters,
acidulated drinks, ginger beer, &c., and also to the "sponging" of
bread, &c.</p>
<p><SPAN id="question_808"></SPAN>808. <i>Why does gunpowder explode?</i></p>
<p>Gunpowder is made of a very intimate <i>mechanical mixture</i> of <i>nitrate
of potash</i>, <i>charcoal</i>, and <i>sulphur</i>. When these substances are
heated to a certain degree, the nitrate of potash is decomposed,
and its <i>oxygen</i> combines with the <i>charcoal</i> and <i>sulphur</i>,
instantaneously forming <i>large volumes of carbonic acid gas</i> and
<i>nitrogen</i>, which, seeking an escape, produce an explosion.</p>
<hr class="bible-verse" />
<p class="center bq">"Thus saith the Lord, Let not the wise man glory in his
wisdom, neither let the mighty man glory in his might, let not the
rich man glory in his riches."—<span class="smcap">Jeremiah ix.</span></p>
<hr class="bible-verse" />
<p><SPAN id="question_809"></SPAN>809. <i>Why does charcoal act as a powerful disinfectant?</i></p>
<p>Because the <i>carbon</i> readily absorbs, and combines with <i>various
gases</i>, neutralising their <i>offensive odours</i>, and destroying their
<i>unhealthy properties</i>.</p>
<p class="bq">Let us now pause for a few moments to consider the importance of
those two great divisions of nature, Air and Water, and to reflect
upon the wisdom of some of those laws which are connected with
the phenomena thereof, and which have not yet been sufficiently
explained.</p>
<p class="bq">We have seen that the air is a thin elastic body surrounding the
globe; that <span class="pagenum"><SPAN name="Page_179" id="Page_179">[Pg 179]</SPAN></span>
it consists of certain gases essential to the life of
animals, and to the growth of plants; and that it takes part in
most of those chemical changes, which mark the transformations
of the inorganic creation. Whether it be the burning of a piece
of wood, the evaporation of a drop of water, the breathing of an
animal, the respiration of a plant, or the fermentation of bodies,
the air in almost every instance gives or receives—and in most of
the operations in which it engages, it does both.</p>
<p class="bq">But there is one point of view, which we must add to those which
have already been considered: the order of nature consists of
generation, life, and death. Every beat of the watch signals the
birth of millions of living things, and the same beat proclaims
that as many living organisms have yielded up their vital spark,
and that forthwith the elements of which they are composed must be
dissolved, and restored to the great laboratory of nature.</p>
<p class="bq">The air is the vast receptacle of those organic matters which are
undergoing dissolution. The body of the shipwrecked mariner, cast
upon the shore of a desolate island, blackens in the sun, and the
full round form gradually dwindles to skin and bone, until at last
the few atoms that remain crumble into dust, and are scattered
to the wind. The same process occurs, with some modifications,
whether bodies are buried in the earth, or dissolve upon its
surface. The leaves of forests fall and accumulate in heaps,
where they ferment and dissolve, leaving only their more earthy
particles behind.</p>
<p class="bq">The amount of matter which day by day passes from the state
of the living to that of the dead, must be enormous; but from
the difficulties of acquiring data, beyond the possibility of
calculation. Such statistics as we have, however, enable us to
form conclusions as to the mighty agencies in which the air
is constantly engaged. There are on the earth 1,000,000,000
inhabitants of whom nearly 35,000,000 die every year, 91,824 every
day, 3,730 every hour, and 60 every minute. But <i>even the living
die daily</i>, and undergo an invisible change of substance, as we
shall hereafter explain.</p>
<p class="bq">The bodies of those many millions are dissolved in the air, in
vapours and gases which, before the dissolution of each corporeal
organism is complete, begin to live again in the various forms of
vegetable and animal life.</p>
<p class="bq">Of the number of animals living and dying upon the face of the
earth, we can form no adequate estimate. Of mammals there are
about 2,000 ascertained species; of birds 8,000 species; of
reptiles 2,000 species; of fishes some 8,000 or 10,000 species;
of molluscs some 15,000 species; of shell fish 8,000 species; of
insects 70,000 species. And, including others not specified here,
the total number of <i>species</i> of animals probably amounts to no
less than 250,000,—each species consisting of <i>many millions</i> of
living creatures.</p>
<p class="bq">In the area of London alone, no less than 200,000 tons of fuel
are annually cast into the air in the form of smoke. And if we
take into account the vast operations of nature in evaporation,
fermentation, and putrefactive decomposition, we may be enabled
to form a conception of the mighty part which that <i>thin air</i>, of
which we think so little, plays in the grand alchemy of nature.</p>
<hr class="bible-verse" />
<p class="center bq">"I will praise thee; for I am fearfully and
wonderfully made; marvellous are thy works; and that my soul knoweth
right well."—<span class="smcap">Psalm cxxxix.</span></p>
<hr class="bible-verse" />
<p class="bq">In addition, also, to the facts already communicated, respecting
the sound-bearing and light-refracting properties of air, it
must be remarked, that but for the atmosphere, and the general
refraction of light by its particles—each atom as it were
catching a fairy taper, and dancing with it before our view—the
condition of vision would be widely opposite to that which exists,
and totally <span class="pagenum"><SPAN name="Page_180" id="Page_180">[Pg 180]</SPAN></span>
unsuited to our wants. The various objects upon
which the illuminating rays of the sun fell, would be lighted up
with an intense glare, but all around would be darkness, just as
when a single ray of light is passed into a dark chamber, and
directed upon a solitary object. The air, without becoming itself
visible, <i>diffuses luminous rays</i>, in modified intensity, in every
direction. If the air reflected so much light as to render <i>itself
visible</i>, it would appear like the glittering surface of the water
reflecting the solar rays, and we should then be unable to see the
various objects which surround us.</p>
<p class="bq">Of the importance of Water in the scheme of creation, man
generally entertains an imperfect conception. It is simply
supposed to afford moisture to plants, drink to animals, and to
promote salubrity by its cleansing properties. Let us, however,
contemplate man as he stands before us, noble in form, erect
in position, full of strength, joy, ambition. How much of that
noble form is composed of water? Suppose that it could all be
instantaneously withdrawn—not the oxygen and the hydrogen, which
might combine to form water—but the fluid that exists in his
body as <i>water</i>, unchanged—except by mechanical admixture with
the secretions of the body—Why then that beautiful temple would
collapse and become a mere shred, so thin, that it would seem but
a shadow of the body as it existed before, and the beholder might
doubt whether life ever inhabited a frame whose structure was so
frail. It is said that <i>three-fourths</i> by weight of the human body
consist of <i>water</i>. Thus, if man weighs 120lbs., 90lbs. consist of
water, and this subtracted, only 30lbs. of solid matter remain.
This statement is rather under than over the fact.</p>
<p class="bq">The assertion is startling, but so true that it can be verified
by simple experiment. A piece of lean flesh—say of beef—cut an
inch thick, and placed in a slow oven, and allowed to remain until
all its water was driven off in vapour, would become as thin as a
wafer, and as light as a cork. With a more scientific arrangement,
it would be possible to collect the water, and the weights of the
condensed vapour, and of the solid residue, would together make
up the weight of the beef: if the piece weighed sixteen ounces,
the weight of the water would be about 14 ounces, and the <i>solid
matter</i> about <i>two ounces</i>.</p>
<p class="bq">Water holds a similar proportion in the bodies of all animals,
and of vegetables. It is evident, therefore, that it occupies a
more important place in the scale of creation than is generally
accorded to it by the unobservant mind. We are indebted to it for
those atmospheric changes which constitute the peculiar feature
of our varying climate. Rising in invisible vapours, it builds
palaces of glory in the skies, and often presents to the view of
man the imagery of heaven. Persons who have ascended above the
altitude of the clouds, have described the scene upon looking down
towards them as the most celestial that the mind can conceive.
Fields of fleecy radiance, majestically rolling like a sea of
gold, occupied the whole range of vision, and seemed to embellish
an eternity of space. Those golden clouds that at one time are
decked in the richest splendour, and occupy the upper chambers
of the Court of Nature, become grave councillors when the earth
grows thirsty, and the plant droops with languor. They roll
their heavy brows together, as in consultation upon some grave
necessity: down come the refreshing showers, the mighty tongue
of thunder rocks the air, the earth is drenched, and becomes
fresh with the salubrity of her toilette; obnoxious substances,
with their offensive exhalations, are swept away: living things
rejoice, and beautiful flowers throw their incense in thanksgiving
into the air; the broad blue heavens for a time look down and
<span class="pagenum"><SPAN name="Page_181" id="Page_181">[Pg 181]</SPAN></span>
smile upon the blessed work; and then the clouds again gather
in a golden train, and one by one fill the high arches of the
atmosphere, until the earth once more grows thirsty, and the
flower supplicates for drink.</p>
<hr class="bible-verse" />
<p class="center bq">"How mighty are his wonders! his kingdom is
an everlasting kingdom, and his dominion is from generation to
generation."—<span class="smcap">Daniel iv.</span></p>
<hr class="bible-verse" />
<p class="bq">With reference to Light, its wonders, and the curious but
imperfect theories respecting it, we have little to add, except
with regard to its physiological action upon the eyes of man
and of animals, which will be given in another place. But of
its sister, Darkness—for it would not do now to call darkness
the antagonist of light, since it will be seen that they work
harmoniously for good—we have to say, that recent discoveries
indicate that darkness is as necessary to the health of nature
as light. Not only is it necessary to compose man and animals
to sleep, to give rest to the over-wrought nerves of the
industrious—but light is the quickening power of vegetation,
and although plants grow by night, they grow, as man does, when
stretched upon his bed—but some of their functions, which
are actively excited in the presence of light, are at rest in
darkness. Nor is this all: there is not an atom upon the face
of the earth which is not affected by the rays of the sun,
their light, their heat, their actinism. Colours change: some
are bleached, others are darkened. All bodies are expanded. The
hardest rock sustains <i>an effect</i> from the sun's rays; and an
unceasing sun, shining upon the hardest granite, would in time
produce such a disturbance of its atomic condition, that adamant
would crumble away to dust.</p>
<p class="bq">The going down of the sun, therefore, marks the period when not
only does the bird fly to her resting-place, and man turn to his
couch; but when <i>every atom of a vast hemisphere</i> subsides into a
state of quietude, and when homogeneous particles of matter return
to their mutual rest.</p>
<p class="bq">In a few succeeding lessons, we intend to point out some of the
scientific truths that are <i>illustrated in the use of toys</i>. We
think we shall be able to show to our young readers, that even the
hours of play may be made the periods of delightful instruction;
and that there is <i>no</i>"reason why" the acquirement of knowledge
should not sweetly accord with the occasional pursuit of those
pastimes by which health of body and vigour of mind are induced.</p>
<p class="bq">But before we commence the discharge of that pleasant duty, let
us say a few words respecting Carbon, that important agent in the
world's history. It is, doubtless, perplexing to the minds of many
persons, to understand how the <i>diamond</i> can be <i>pure carbon</i>;
how
<i>charcoal</i> can be <i>carbon</i> a <i>little less pure</i> than the diamond;
and how <i>coal</i> and <i>sugar</i> can also be carbon, <i>less pure</i> than
the charcoal. The statement that in the diamond carbon exists in
a different atomic condition, is almost as instructive to the
inquiring mind, as to say, "It is so, <i>because it is</i>."</p>
<p class="bq">Diamonds are expensive things, and so difficult to experiment
upon, even if they were not expensive, that the doors of inquiry
seem locked. To turn diamonds into charcoal, or into carbonic
acid gas, is a very costly formula of experiment. Charcoal fires,
thus sustained, would soon burn a man out of his house; and soda
water, impregnated with carbonic acid gas, produced from diamonds,
would be a very expensive beverage. If we could only turn charcoal
into diamonds, and carbonic acid gas into brilliants, that would
be quite another affair. A new Eldorado would be discovered,
and there would be so many experimenters that, when they all
succeeded, they would find that diamonds had lost their value.
However, as a fact for the encouragement of those who would like
to be early in the race, we may state that the atoms of
<span class="pagenum"><SPAN name="Page_182" id="Page_182">[Pg 182]</SPAN></span> charcoal
which are repulsed from the charcoal points, during the electric
agitation which produces the electric light, acquire a hardness
and a sharpness almost equal to that of the diamond—only there
is still the awkward obstacle in the way, that <i>they happen to be
black</i>.</p>
<hr class="bible-verse" />
<p class="center bq">"He delivereth and rescueth, and he worketh signs
and wonders in heaven and in earth."—<span class="smcap">Daniel vii.</span></p>
<hr class="bible-verse" />
<p class="bq">We must see, therefore, whether there is anything in nature that
we can experiment upon, theoretically or practically, to give us
a clearer conception of this difficult matter. There is a large
<i>dew-drop</i> resting upon a luxuriant cabbage leaf—one of those
great leaves that have flourished in defiance of the snail, and
now spreads out like the gigantic frond of the <i>Victoria Regina</i>.
That dew-drop is one of the beautiful diamonds which Nature
sprinkles about on cloudless nights, as if to show the stars,
in answer to their twinkling, that we have something that will
glisten and twinkle too.</p>
<p class="bq">The dew-drop is a very good imitation of a diamond, and to the
lover of God's works, quite as precious as the stone set in gold.
It does not consist of carbon—it probably may have a mite of
carbonic acid in its embrace—but that is not necessary to our
purpose: all we want to know is, <i>the different atomic conditions</i>
of which bodies are susceptible, and the very dissimilar
appearances they exhibit under the variations of atomic states. It
doesn't glisten so much as the diamond, <i>because it is round</i>—if
we could cut it into a number of <i>facets</i>, it would refract light
almost as perfectly as the diamond. It is not <i>solid</i>—but we
can freeze it, and we shall at once exhibit two different atomic
conditions, that will represent nearly enough the diamond, and
the liquid carbonic acid. Then, if we evaporate the dew-drop, we
shall produce a volume of vapour nearly <i>two thousand times as
large as the dew-drop</i>. The steam will be white; but we have only
to imagine it black, and then we get an analogy of the differences
of the atomic conditions that prevail in <i>the diamond</i>, <i>carbonic
acid</i>, and <i>charcoal</i>, <i>tinder</i>, <i>lamp-black</i>, or any light form
of carbon. Of course we have been illustrating <i>atomic conditions
only</i>, and not chemical composition.</p>
<p class="bq">There are a few other facts connected with carbon that merit
consideration. Carbonic acid gas, <i>entering the lungs</i>, is a
<i>deadly poison</i>;
but <i>entering the stomach</i>, which lies close
under the lungs, and is over-lapped by them, it is a <i>refreshing
beverage</i>. Although charcoal, when burnt, gives off the most
poisonous gas, it seems to be very jealous of other gaseous
poisons; for if it be powdered, and set about in pans where there
is a poisonous atmosphere, it will seize hold of poisonous gases,
and, by absorbing, imprison them. Even in a drop of toast and
water, the charred bread seizes hold of whatever impurities exist
in the water; and water passed through beds of charcoal, becomes
filtered, and made beautifully pure, being compelled to give up
to the charcoal whatever is obnoxious. If a piece of meat that
has already commenced putrifying, be sprinkled with charcoal, it
will not only object to the meat putrifying any further, but it
will <i>sweeten that which has already undergone putrefaction</i>.
Although, in the form of gas, it will poison the blood, and cause
speedy stupefaction and death; if it be powdered, and stitched
into a piece of silk, and worn before the mouth as a respirator,
it will say to all poisonous gases that come to the mouth with the
air, "I have taken this post to defend the lungs, and I arrest
you, on a charge of murderous intention." Such are the various
facts connected with carbon; and they forcibly indicate that those
who understand Nature's works, are likely to receive her best
protection.</p>
<p><span class="pagenum"><SPAN name="Page_183" id="Page_183">[Pg 183]</SPAN></span></p>
<hr class="bible-verse" />
<p class="center bq">"The father of the righteous shall greatly
rejoice; and he that begetteth a wise child shall have joy of
him."—<span class="smcap">Proverbs xxiii.</span></p>
<hr class="bible-verse" />
<hr class="chap" />
<div style="break-after:column;"></div><br />