John Wesley.

A survey of the wisdom of God in the creation; or, A compendium of natural philosophy .. (Volume 3) online

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That this fire is inconceivably subtle, appears from its
permeating even iu the densest metals, and that with
il 4



178

such ease, as to receive no reeeptible resistance. If
any one doubt, whether it pass through the ?ub*tance, or
only along the surface of bodies, a strong shock taken
through* his owu body, will prevent his doubting any
longer. It differs from ail other matter in this, that the
particles of it repel, not attract each other. And hence
is the manifest divergency in a si ream of electrical
effluvia. But though the particles of it. repel each other,
yet are hey attracted by all other matter. And from
these three, the extreme subtlety of this fire, the mutual
repulsion of itspaits, and the strong attraction of them
by other matter, uriaes this effect, that if any quantity of
eisctric tire be applied to a mass of common matter of
any bigness^pr length, (\\liich has not already got its
quantity) it is ittituediatcty doTufced through the whole*

It seems this globe of earth and water, with its plants,
animals, buildings, have diffused through their whole
substance, just as much of this fire as they will contain.
And this we may term their 'natural quantity. This is
not the same in all kinds 0f matter : neither in the same
kind of matter, in all circumstances. A solid foot of one
kind of matter (as glass) contains more of it than a soiid
foot of another kind. And a pound weight of the same
kind of matter, when rarefied, contains more than it did
before.

We. know that this fire is in common matter, because
we can pump it eut by the globe : we know that common
matter has near as much of it as it ran contain, because
if we add a little more to any portion of it, the additional
.itiiY does not enter, but forms a kind of atmosphere
xound it. On the other hand we know, that common
matter has not more of it than it can contain. Other-
wise ail loose portions of it would repel each other; a*
they constantly do, when they have such atmospheres.
Bud the eauli, for instance, as much electric lire in
proportion, as we can give to a globe o iron or wood,
the particles of dust and other light matter, would not
only repel each other, but he continually repelled from
Hence, the hir, b.eiiig constantly loaded



179

-with woulu be unfit for respiration, Here we see

>er occasion to adore that wisdonv which has made
ail things by weight and measure.

The form of every electric atmosphere is that of the
body which', it surrounds, because it is attracted by every
part of the' surface, though it cauuot enter the substance
already replete. Without this attraction, it would not
remain round the body, but dissipate into the air.

The atmosphere of an electrified sphere is not rnore
equally drawn oir from any one part of it than from ano-
ther, because it is easily attracted by every part. But it
is not so with bodies of other figures, From a cube it is
more easily drawn off at the corners that at the sides :
and so from the corners of bodies of any other form,
and most easily from the sharpest corners. 'For the
force with which an electrified b< dy retains its atmos-
phere is proportioned to the surface on which that at-
mosphere rests. So a surface four .inches square retains
its atmosphere with sixteen times the force that one of
an inch square does. And as in pulling the hairs from a
Horses tail, a force insufficient to pull off a handful at
once, could easily pull it off hair, by hair: so though, a
blunt body cannot draw off alt the atmosphere at once,
a pointed one can easily draw it off particle by particle.

While the electric fire, which is in all bodies, is left to
itself, undisturbed by any external violence, it is more
or less dense, according to the nature of the body w Inch-
it is in. In dense, bodies it is more rare : in rare bodies
it is more dense. Accordingly every body contains such
a quantity of it, rare or dense, as is suitable, to its
nature. And there is some resistance to every endeavour
of altering its density, in the whole of any body, or iu
any part of it. For all bodies resist either the increase
or diminution of their natural quantity. And on the
other hand, when it lias been either increased or dimi-
nished, there is a resistance to its return to Us natural
state.

With regard to the different resistance niade by Jif
r 5



180

ferent bodies in either of these cases, it is an invariable
rule, that glass, wax, rosin, brimstone, silk, hair, and
such like bodies, resist the most : and next to these, the
air, provided it be dry, and in a sufficient quantity.
Tiiat this resistance is least in metals, minerals, water,
animals,, and vegetables, which we may rank together,
because the difference in their resistance is very incon-
siderable : and that in these bodies the resistance is
greater, when their surfaces are polished,, and extended
in length, that when their surfaces are rough and short,
or end in sharp points.

When a body has more electric fire forced into it,
than it has naturally, it is said to be electrified posi-
tively. When part of the natural quantity is taken
away, it is, said to be electrified negativety. Now when
an iron bar is negatively electrified, the fire drawn out
does not go in again as soon as the experiment is over,
but forms an atmosphere round it, because of the re-
sistance it finds in its endeavour to dilate itself, either
into the air, or into the bar. And when it is electrified
positively, the same kind of atmosphere is formed by
the fire accumulated upon it. Whether therefore bodies
are electrified negatively or positively* and remain so
when the experiment is over, there are similar atmos-
pheres surrounding them, which, will produce similar
effects.

But we can electrify no body beyond a certain de-
gree ; because when any is electrified to that point, it
has an atmosphere round it sufficiently strong to balance
any power that endeavours to electrify it farther.

And in the ordinary course of nature this subtle,
active fluid, which not only surrounds every gross body,
but every component particle of each, whore it is not
ill absolute contact with its neighbouring particle* can
never be idle, but is ever in action, though that action
be imperceptible to our senses. Jt is ever varying its
condition, though imperceptibly, in ail parts of ail
bodies whatever; and electrifying them more or less,
though not.so forcibly as to give sensible signs of it



181

All bodies then, and all their component particles, when
in their natural situation, have round their surfaces,
where they are not in absolute contact with other sur-
faces, an imperceptible atmosphere, sufficient to balance
the smaller force with which they are attacked : every
way similar to the perceptible atmosphere of bodies
forcibly electrified. In these imperceptible atmospheres
is placed the power which resists their being electrified
to an higher degree than they are naturally. And this
power lies in ihe elasticity of the subtle fluid, every
where dispersed both round all bodies and in them*

Glass is very difficulty electrified, which seems to
prove it has a very dense electric atmosphere. Metals
are easily electrified ; consequently they have rare, and
therefore weakly resisting atmospheres. But as heat
rarefies all bodies, so if glass be heated to a certain
degree, even below melting, it will give as free a passage
to the electric fire as brass or iron does : the atmosphere
round it being then rendered as rare as that of metals.
Nay, when melted, it makes no more resistance than .
water. But its resistance increases as it cools ; and
when it is quite cold it resists as forcibly as ever.
Smoothly-polished wax resists as much as glass. But
even the small heat raised by rubbing will render its
atmosphere as rare as that of metals, and so entirely
destroy its resistance. The same is true of rosin and
brimstone. Even the heat arising from friction destroys
the resistance which they naturally make to being, elec-
trified : a strong proof thai the resistance of all bodies
thereto, is exerted at their surfaces, and caused by an
electric atmosphere of different- densities, according to
their different circumstances, .

Most experiments willsucceed as well with' a globe of
brimstone as with one of glass, Yet there is a consider-
able difference in their nature^ What glass repels, brim-
stone (as also rosin) attracts. Rubbed glass emits the
dectric fire : rubbed brimstone, rosin, and wax,, receive it*
Heace if a glass globe be turned at one end of a prime
i .6-'



conductor, and a brimstone one at tlie otli^r, rrof a.
spark of fire can be obtained ; one receiving it in as-
fast as it is given out by the other. Hence also if a,
phial be suspended on the prime conductor, with a
chain from its coating to the table, and only one globe
turned, it will be electrified or charged as they term it)
by twenty turns of the wheel : after which it may be
discharged, thai is, unelect rifted, by twenty turns of the
other wheel.

The difference between non electrics (vulgarly speak-
ing) and electrics per se, is chiefly this. 1 . A non electric
easily suffers a change in the quantity of fire it con-
tains. Its whole quantity may be lessened, by drawing
out a part, which it will afterwards resume. But you
ean only lessen the quantity contained in one of the
surfaces of an electric : and not that, bat by adding at
the same time an equal quantity to the other surface ;
so that the whole glass will always have the same
quantity ia its two surfaces. And even this can be only
done in glass that is thin : beyond a certain thickness
"we know no power that can make this change. 2. The
ethnical fire freely moves from place to place, in and
through the substance of a non-electric, but through the
guhstaice of an electric it will by no means pass. Jt
freely enters an iron rod, and moves from one end to
another, where the overplus is discharged. Bat it will
3iot enter, or move through a glass rod. Neither will
the thinnest glass whiclrean be made suffer any particle
of it eateii ig one of its surfaces to pass through to the
other.

Indeed it is only metals and liquids that perfectly
conduct (or transmit) this lire. Otuer bodies seem to
conduct it only so far as they contain a mixture of
these ; accordingly, moist air will conduct it in pro-
portion to its moistnesvs. But dry air will not conduct
it at all: on the contrary, it is the main instrument in
confining any electric atmosphere to the body which it
Surrounds. Dry air prevents it dissipating (which it doe*



183

presently when in vacuo) or passing 1 from body to body.
A clear bottle full of air, instead of water, cannot be
electrified. But exhausted of air, it is electrified as
effectually as if it was full of water. Yet an electrical
atmosphere and ak do not exclude one another ; for we
breathe in it freely, and dry air will blow through it
without altering it at all.

When a glass phial is electrified, whatever quantity of
fire is accumulated on the inner surface, an equal quantity
is taken from the outer. Suppose, before the operation
begins, the quantity of fire contained in each surface
is equal to twenty grains : suppose at every turn of the
globe one grain is thrown in : then after the first stroke
there are twenty-one within, nineteen only without : after
the second, the inner surface wiil have twenty-two, the
outer but eighteen : and so on, till after twenty strokes,
the inner will have forty, the outer none. And the
operation ends : for no power or art of man can throw
any more on. the inner surface, when no more can be
taken from, the outer. If you attempt to throw more
iu, it is thrown back through the wire, or flies out in
cracks through the sides of the phial. The equilibrium
cannot be restored in this phial, but by a communication-
formed between the inner and outer surface, by some-
thing external touching both the outer and the wire
which communicates with the inner surface. If you
touch these by turns, it is restored by degrees : if both,
at once, it is restored instantly. But then there is a
shock occasioned by the sudden passing of the fire
through the body in its way from the inner to the outer
surface. For it moves from the wire to the finger, (not
from the linger to the wire, as is commonly supposed.)
Thence it passes through the body to the other hand,
and so to the outer surface.

The force with which this shock may be given is far
greater than one would conceive, ft will kill tats, hens,
or even turkeys, in a moment: others that are not quite
killed,, it strikes blind, It will give polarity to a fine



184

needle, making it point north and south, as if touched
by a loadstone. It will invert the polarity of a compass,
and make the north point turn to the south. At the
same time the ends of the needles are finely blued like
the spring of a watch. It will melt off the heads and
points of pins and needles, and sometimes the whole
surface of the needle is run, and appears, as it were,
blistered, when examined by a magnifying glass. It
will melt thin gold or silver, when held tight between
two panes of glass, together with the surface of the
glass itself, and incorporate them in a fine enamel.
Yea, a strong spark from an electrified phial makes a
fair hole through a quire of paper doubled, which is
thought good armour against the push of a sword, or
even a pistol bullet. And it is amazing to observe in
how small a portion of glass a great electrical force may
be. A thin glass bubble, about an inch diameter, being
half filled with water, partly gilt^ on the outside, when
electrified gives as strong a shock as a man can well
bear : allowing then that it contains no more fire after
charging than before, how much fire must there be in
the small glass ? It seems to be a part of its very sub-
stance. Perhaps if that fire could be separated from
it, it would be no longer glass. It might in losing this,
lose its most essential property, its transparency, brittle-
ness, and elasticity.

Some have not improbably supposed, that all electric.
bodies, so called, are by their original constitution,
thoroughly saturated with electric fire: that it remains
fixed in them, (unless while the texture of those bodies
is quite altered by liquefaction) that fire fixed in a body
constitutes an electric > and all bodies where it is not fixed
are non electrics. Agreeably to which they suppose,
that in all non electricf 9 t\\e original fire loosely inhering,
is easily driven on bv the new collected fire, which then
possesses its place : but that in dec tries -the original fire
being impacted into their substance, and therefore more
firmly inhering, will uot give way to, or be driven on
by, the new collected fire'. Such is air in particular,



185

with the particles of which the original fire is closely
incorporated. Dry air seems to be so fully saturated
with it, that it is scarce capable of receiving any more ;
whereas ail new-collected tire is continually endeavour-
ing to return into the earth. Let wires be electrified
ever so strongly, yet the moment any part of them is
touched by a person standing on the floor, they are
electrified no longer ; all the tire escaping through him
into the earth.

Upon the principles of electricity we may give a more
rational account of many appearances in nature than
has yet been done : of thunder and lightning in par-
ticular. In order to which we may observe, all elec-
trified bodies retain the fire thrown into them, till some
non-electric approaches : to which it is then communi-
cated with a snap, and becomes equally divided.-
Electric rire is strongly attracted by water, and readily
mixes with it. And water being electrified, the vapours
arising from it are equally electrified. As these float in
the air, they retain the additional tire till they meet with
clouds not so much electrified ; then they communicate
it with a shock.

The ocean is compounded of water and salt> one an
electric, the other not. When there is a friction among
the parts near its surface, the fire is collected from the
parts below. It is then plainly visible in the night, at
the stern of every sailing vessel. It appears from every
dash of an oar : in storms the whole sea seems on fira.
The particles of water then repelled from the electrified
surface continually carry off" the fire as it is collected.
They rise and form clouds which are highly electrified,
and retain the lire till they have aa opportunity of dis*
charging it.

Particles of water rising in vapours attach themselves
to particles of air. One particle of air may be sur-
rounded by twelve particles of water as large as itself,
sli touching it, and b- more added to them. Particles



of air thus loaded would he drawn i; carer together bj
the mutual at-raetbii of the

t!v fi-e, co;nm >:i or electri.c, included therein, assist
their mutual repulsion. Hence they coj.tL'i'ue sus-
pended. But if air thus loaded be compressed by ad-
verse wLr.ls, or by being driven against mountains, or if
condensed by the loss of its fire, it will continue sus-
pended no longer, but will descend in dew. And if the
. ounding one particle of air conies into contact
with that surrounding another, they naturally coalesce
if-.o a drop, and so descend iu rain.

The sun supplies common fire to all vapours rising
either from sea or land. Vapours having both this and
electric fire, are better supported than those which have
this only. For when vapours rise into the coldest region,
the. common fire may foil.. But the cold will not di-
minish the electric : this is always the same. Hence
clouds raised from fresh waters, from moist earth, or
growing vegetables, more easily descend and deposit
thffir waters, as having but little electric fire, as to keep*
the particles separate from each other; so that the
greatest part of the water raised from the land falls on
the laud again. But clouds raised fiorn the sea, having
both fires, and much of the electric, support their
water far more strongly, and being assisted by winds*
rnuy bring it from the middle of the widest ocean to the
middle of the broadest continent. Ami yet a way ifr
provided whereby these also are readily brought to de-
posit their water. For whenever they are driven against
mountains by A .ne aids, those mountains take away
their electric fire ; and, being cold, the common also :
"hence the particles iann^ lately clos-c. If the air is not
much loaded, the water falls in a dew on the top and
the sides erf the mountain. If it is* the electric fire
being taken at once from the whole cloud, it flashes-
brightly, and cracks loudly. And the particles instantly
coalescing for want of that fire r fall m a, heavy shower*

When a ridge of mountains stops the clouds, and
draws the electric fire from the cloud first; approaching



187

ft, the next, \vhen it comes near the first, nmv dfe-
prived of its fire, flashes into it, and deposits its own
water. The third cloud approaching, and ail that suc-
ceed, act in the same manner, us tar back as they ex-
tend, which may be for several hundred miles. Hence
the continual storms of thunder, lightning, and rain, o
the east side of those vast mountains, the Andes, which,
running north and south, intercept ail the clouds brought
against them from the Atlantic Ocean. In a plain
country there are other means to make them drop their
water. For if an electrified cloud, coining from the
sea, meets in the air a cloud coming from the land, and
therefore not elect lined, the first will give its flash into
the latter, and thereby both will be made to deposit
their water. The concussion of the air contributes also
to shake down the water not only from those two clouds,
but from others near them. When the sea and land
clouds would pass at too great a distance from each
other, they are mutually attracted, till within the distance.
For the sphere of electrical attraction is fur beyond the
Hashing distance. And yet where a cloud contains much
fire, it may strike at a considerable distance. When a
conductor has but little fire in it, you must approach
very near before you can draw a spark. Throw into it
a greater quantity of fire, and it will give a spark at a
greater distance. But if a gun barrel, when electrified,
will strike and make a noise at the distance of an inch,
at what a distance, and with how great a noise, may ten
thousand acres of electrified cloud strike I No wonder
that this should melt meials, (which our artificial Hash*
docs in some degree,) though perhaps not so properly by.
its heat, as by insinuating into the pores, and creating <t
violent lepulsion between the particles of the metal it
passes through. This overcomes the attraction whereby,,
they cohere, and so melts the metallic body. And this
accounts for its melting a sword in the scabbard, or gold
in the pocket, without burning either.

But thunder-clouds do not always contain more than
their natural quantity of electric iire. Vtjry frequently
they contain less. And wheu this is the case, wheat



188

they are negatively electrified, although the effects and
appearances are nearly the same, yet the manner of
operation is different. For in this case, it is really the
fire from the mountains, or other parts of the earth,
which strikes into the cloud : and not as we imagine,
fire from the cloud which strikes into the earth. And
we may easily conceive how a cloud may be negatively
electrified. When a portion of water is rarefied into a
thin vapour, the fire it contains is rarefied too. Con-
sequently it has then less than its natural quantity of
fire. Such a cloud therefore coming within a due
distance of the earth, will receive from it a flash of
electric fire; which flash, to supply a great extent of
cloud, must often contain a great quantity of fire.
Such a cloud aiso pacing over woods of tall trees, may
silently receive some ^app;y either from the points of
the boughs, or from the sharpest ends and edges of the
leaves. The cloud thus supplied, flashes into other
clouds that have not been so supplied ; and those into
others, till an equilibrium is produced, among all that
are within a striking distance of each other. And hence
are repeated strokes and flashes, till - they descend iu
showers to the earth, their original. Rain, especially
when in large drops, generally brings down the electric
fire: falling snow, often: summer hail, always, though
silently. Consequently any of these may prevent thunder
and lightning; or, at least abate its violence. Rain is
helpful in another respect likewise. By wetting men or
beasts, it saves many lives. For if your clothes are
thoroughly wet, and a flash of lightning strikes the top
of your head, it will run in the water over the surface
of your body in the ground : whereas if your clothes
were not wet, it would go through your body. Hence
a wet chicken cannot be killed by a stroke from the
phial :. whereas a dry one is killed in an instant. See here
also the wisdom and goodness of Him, who sendefh
forth lightning with the rain ! It should likewise
be observed, that wherever electrified clouds pass spires,
towers, chimnies, and high trees, as so many points draw
the electric fire, and the whole cloud frequently dis-



189

charges there. Therefore it is highly dangerous in such
a storm, to take shelter under a tree.

Commou fire is more or less in all bodies, as well as
electrical. If there be a sufficient quantity of either in
any body, it is inflamed. But when the quantity of
common fire jherein is small, there needs more electric
fire to inflame it. Where the quantity of common fire
is greater, less or" the electric will suitice. So if spirits
are heated, a small spark inflames them ; if they are not,
the spark must be greater. Sulphureous vapours, whe-
ther rising from the earth, or from stacks of moist hay,
or corn, or any other healed, and reeking vegetable, con-
tain abundance of common fire ; a small addition of
electric then will inflame them ; therefore they are easily
kindled by lightning.

Any who would be clearly convinced of the nature of
lightning, may make the following experiment. Make
a small cross of two thin strips of wood, the arms being
just so long as to reach the four corners of a large, thin
silk handkerchief when extended. Tie the corners of
this to the extremities ot the cross ; and so you have
the body of a kite : add to this a proper tail, loop, and
string, and it will rise in the air like one made with
paper: but this is fitter to bear the wind and wet in a
storm without tearing. To the top of the cross fix a


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Online LibraryJohn WesleyA survey of the wisdom of God in the creation; or, A compendium of natural philosophy .. (Volume 3) → online text (page 16 of 24)