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An Essay to Shew the Cause of Electricity
An Essay to Shew the Cause of Electricityполная версия

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An Essay to Shew the Cause of Electricity

Язык: Английский
Год издания: 2017
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John Freke

An Essay to Shew the Cause of Electricity / and Why Some Things are Non-Electricable

SIR,

Those who have the Honour of your Acquaintance, and thence know your many excellent Qualifications, must applaud my Choice in dedicating this small Piece to you; whose Name, if there be any Merit in the Performance, will, before any other, add a Lustre to it. I am, with the highest Esteem,

Your most Obliged,Humble Servant,John Freke.
The PREFACE

When I first enter’d on this Subject of Electricity, I intended only to put some Thoughts in Writing concerning it, that I might the more easily convey them to the Understandings of such as I hoped would be more likely than I should be to go farther with it. And as nobody, either here or abroad, had published any thing touching the Cause from which it was produc’d, I chose to shew the Beginning I had made to some Friends, whose Opinion concerning Natural Knowlege I had a great Reliance on. I told them, I thought my Difficulty would be to convey what I had to propound on this new Subject to them with the necessary Clearness, as my Intention was to observe the utmost Brevity in it.

After I had read it to them, they assured me that what I had written was perfectly intelligible; and that it gave them many new Ideas respecting this Phænomenon; and were very earnest with me to print it, for the sake of the Publick.

I was not, however, inclined to comply with their Requests, till I had shewn it to a Person who is most justly distinguish’d for his great Candor, and superlative Understanding in all Natural Knowlege; and he likewise having express’d his Wishes to see it in Print, I could not but look on his Desire as a Command.

If what I have here undertaken to shew should enlighten the Minds of any of my Readers, or if it should so far awaken the Attention of others, as to make them give better Reasons for the Operation of this Power of Electricity than I have done, I shall not account the Time ill spent, which I have employ’d on this interesting Subject: A Subject which can, with more Nobleness and Dignity employ the Mind of Man, than any I can think of relating to the sublunary Part of this World. For by it you may be acquainted with the immediate Officer of God Almighty, which he seems to send to all Things living. Nay, this Power, according to my Conception, seems to be the Cause, under HIM, both of Life and Death. And when it may be more fully understood, it may afford us Means whereby we may be better enabled to reason more intelligibly than now we can, concerning various Operations in Nature.

I am very sensible what Tribute a new Author is liable to pay to Criticks: I know it is too common to find much too large a Part of them inclin’d to look into a Book for its Faults, rather than for its Use; and are more ready to pull down, than they have Abilities to put any thing in its Place. But as I am not writing this for any Gain to myself, but the Pleasure of informing, if I can, the Minds of such as may be informed by it, I chuse rather to stand their Censure, than deny the Publick what may possibly be the Beginning of much Good.

It is very probable, that those who pretend to know every thing, will be so good as to say, if they like what I have advanc’d, that it squares exactly with what they thought before concerning it: And those who set up for Criticks will try their Hands at this Performance, and, if they can, will condemn it.

It would be a great Wonder, indeed, if this should escape the Censure of some, when the great Dr. Harvey had his implacable Adversaries to his Account of the Circulation of the Blood; and even Sir Isaac Newton met with Opponents to several of his Theorys. What I have said opposes no one’s Scheme, that I know of; it offers no Sentiments which can hurt any Man.

I have advanc’d only Conjectures for the clearing those Truths I would establish; and if, after all, what appears reasonable to me should not appear so to others, I cannot help it: For it is impossible for all Men to see the same Thing in one and the same Light, even though they were Men of the best Erudition. I would hope, that what I have undertaken to shew, is what all sensible Men would be glad to have shewn.

Kind Sir,

When I reflect on the great Ingenuity you have shewn, in your Apparatus for the Improvement of the Knowlege of Electricity, and how industrious and kind you have been in communicating the many Experiments you have made to your Friends and Acquaintance relating thereto, I was in hopes, from you or some of them, an Essay would be made ere this, not only to go farther with these Experiments, but to give some tolerable Conjecture from whence this Fire, and astonishing Effect, is produced.

I was going to give you my Thoughts concerning it, when I last saw you at Child’s Coffee-house; but, on Reflection, I chose rather to do it in Writing: For, in all Novelty, till the Relater is quite understood, Words are forgotten easily; but Things of this sort in Writing may again and again be consider’d.

To begin then: In order to shew whence this electrical Fire and Force is produc’d, I will first endeavour to prove, that it arises not from any of the Apparatus itself; not either from the glass Ball, nor the Leather, nor from the Tube, or Hand that rubs it: Because nothing we know of can send out of it a Quantity of Matter, but there must be less of that Matter remaining, after it has been so discharged; whereas it cannot be shewn, but that the Ball of Glass, after ever so many Times using, remains as fit for the same Use as at first.

Having, from Probability, I think, shewn, that the Fire and Force, here treated of, come not from the Apparatus, it is natural for me to suppose they are produced from the Air they are mov’d in. And I believe this Notion will not appear trifling, when we consider, that the most ancient and ablest Philosophers have look’d upon the Animal and Vegetable World as actuated by Fire; and that they are nourish’d by Water, and what it contains. If this be allow’d, then the Air, which is esteem’d the Pabulum Vitæ, from its rubefying the Blood of all Animals in Respiration, seems to be universally impregnated with this Fire. And tho’ there is not enough of it so dispersed as to hurt the Animals in Respiration, yet I can suppose it as universally dispersed, as I can a small Quantity of any Liquor dropp’d in Water, which, when so dispersed, is of no Harm to a Patient, though a few Drops of it by themselves would have been certain Death. And yet, if you farther consider it so dispersed, you cannot consider one Particle of the Water without a Particle of the Medicine: Just so it may be with the Fire of this lower Region, or, what I chuse rather to call it, this Flamma Vitalis.

I proceed now to consider, how this Fire, so dispersed, may be collected; and have given to it, in electrical Experiments, a Force equal to, and of the same Nature with, Lightning.

To make this Conjecture the more easily apprehended, I will suppose, that the Nature of Fire is as similar to its Parts, and they have as great a Propensity to adhere to one another, as we find the different Arrangements in all natural Bodies have; as may be seen in Gems, in Water, and in the various Strata of the Earth, and the like. Do but force or invite these fiery Particles to a closer Contact than they have been supposed to be in, when uniformly dispersed through all Nature, and they are Lightning, or a Fire of less Force, as more or less Parts of that Fire are got together.

To illustrate this, wax a small Thread, or slide a Rope swiftly thro’ your Fingers, and you are liable to burn them: Which probably arises from their grinding in, betwixt your Fingers and the Rope, so many more Particles of Fire than naturally come together when left to float in the Air.

If this Reasoning be allow’d to be just (which it must be, till it is overturn’d by stronger Reasoning), then it follows, that the Air, which is violently ground or rubb’d betwixt your Hand and a glass Tube, or betwixt a glass Ball whirl’d briskly, and rubb’d with a Piece of Leather, as they are used in electrical Experiments, I say, the Air, so rubb’d, may leave behind it that Quantity of agitated Fire which causes Electricity.

For, suppose the Ball or Tube inveloped with a Quantity of this Fire moving spirally round them, with the utmost Velocity; and it can no more depart from its Company than you find Sparks of Fire which fly from Steel on a Knife-grinder’s Wheel are liable to do. Every body almost can remember to have seen them adhere to the Wheel, and frequently pursue each other quite round it.

Those who try these Experiments, find, that in moist Weather this Power is less attainable than in a more clear Day; and therefore some may be liable to attribute that to the Apparatus, which may be better accounted for by the watry Particles in the Air; which may be liable to hinder the lambent Flame, by me supposed to be universally scatter’d, from uniting, by the Friction before-mention’d.

As I have mention’d Friction, I cannot help observing how unphilosophical and unmeaning it is, for any one to advance, that Fire is caused by Friction; when I think he may as well say, that Water is caused by Pumping.

We know, that a Cart or Coach-Wheel, for Want of Grease, by Friction will be set on Fire; and Fire-Canes, rubbed together smartly, will take Fire; but neither of these, I believe, nor any thing else, will beget or generate the Element of Fire. They must either collect it out of the Air, or else it must be lodged within them, as we find it to be in Steel in an eminent Degree: For, if you drop the Filings of Steel through the Flame of a Candle, it sends out the most fierce Fire of any thing in Nature.

The Reason to be given why a greater Quantity of Fire is produced from Steel-Filings, than from any other Thing, I take to be owing to a larger Share of that Element which is impacted in it from its being made out of Iron long impregnated with Fire.

Many other Bodies have actual Fire impacted in them, as Flints, and many other hard Stones and Metals; but whenever you produce Fire from Steel-Filings, you find that Steel melted: So when Fire is produced from Stones, and the like, each Spark is Part of that Stone burnt to a Calx.

Now, as I am endeavouring to shew to you the natural Cohesion of Fire, and the Propensity there is in it to extend itself, I shall offer to your Consideration a very familiar Instance to prove it; which is that of the Snuff of a Candle just blown out. You cannot but have observ’d at how great a Distance from the Snuff the Flame will descend down the Smoke, and light it.

I shall further take the Liberty to observe to you another Proof of this; which, I think, will not only shew a Propensity in Fire to cohere, but will greatly strengthen my Conjecture, that this Fire, produced in Electricity, is extracted from that I have supposed to be universally dispersed.

A Person, who liv’d in the Town of Warham in Dorsetshire, in the Year 1703, informed me, that in the Night of the great Hurricane and high Wind, in the strongest Part of the Tempest, he saw from his Window, on the neighbouring Hills, great Bodies of Fire, swiftly passing over them on the Ground. – Now whence arose that Fire, if it came not from the Air impelling it into those Flakes? And its subsisting together in that Hurricane shews, I think, very plainly, that if its Cohesion had not been natural, the Wind would then have scatter’d it.

Though I apprehend that the Four Elements of Fire, Water, Earth, and Air, may never have been increased or diminished, since the Great God of Order created them, yet I can also apprehend each of them unequally dispers’d in the Universe by various Causes and Events: And when this happens, those which were intended, when in their due Order, to make every thing happy and easy, in their disordered State will create nothing but Confusion.

For Instance, the chief Use of Water seems intended, when descending in warm and gentle Showers, or flowing in kind and easy Streams, to chear and nourish all Kinds of Vegetation, as well in Trees and Plants, as in Herbs and Flowers: But suppose, by the Contrivance of Man, or by the Accidents of Nature, a large Quantity of it lodged on the Tops of high Hills, if it breaks its Bank, it will never stop, till it finds a natural resting Place; and in its Torrent it will overwhelm and destroy those Trees and Plants, with the Herbs and Flowers, it was intended to nourish.

The like may be said of the Fire, which I have been supposing uniformly dispersed over the Creation; which, if its Properties are to invigorate all Nature, you must of course suppose its Power not to be controul’d; but that it passes through all the Animal, Mineral, and Vegetable Creation, whilst they stand in need of Life, or any Increase.

But as I have been conjecturing what different Purposes Water in its disorder’d State may produce, so the same Consideration may be had concerning Fire in its disorder’d State: When too much of it is brought together, either by the Contrivance of Man, or by the Disorders in the other Elements; is it not reasonable to suppose, that it will, according to its natural Appointment, get about its Business, and break as soon as it can from its Confinement?

A very learned and eminent Author, who is now living, says, “That all Life, whether it be vegetable, sensitive, or animal, is only a kindled Fire of Life in such a Variety of States: And every dead insensitive Thing is only so because its Fire is quenched.”

It had been impossible that this wonderful Phænomenon of Electricity should ever have been discover’d, if there had not been such Things as are non-electricable. For, as fast as this Fire had been driven on any thing, its next Neighbour would have carried it further: But, when it was most wonderfully found out, that any thing which was suspended in a silk Cord (that being a Non-electricable) was obliged to retain the Fire, which by electrical Force was driven on it; and when, moreover, it appeared, that any Person or Thing being placed on a Cake of Bees-wax (which also is a Non-electricable), it could no more part with its Fire, than when suspended in a silk Cord, I think it will become worth Inquiry, why they are not electricable.

To prove this, I would reflect upon the Passage before-quoted: For from thence I think it must follow, that if Fire be the Cause of the Life and Increase in any thing, then, whatever ceases to be in a State of Life or Increase, can no longer be supposed to be capable of them; and therefore must be consider’d as a Caput Mortuum. Of this sort are Bees-wax and Silk, both being non-electricable.

To pursue this kind of Reasoning concerning them: They are, in truth, the Excrements only from those Beings which once had Life in them; the Wax being the excrementitious Matter from Bees, which, when made, was to be capable of no further Increase or Addition to its Nature: For, as its primitive Use was only intended to make Combs or Cells to preserve the Honey through the different Changes of the Season, so if this Wax had been liable to Alterations from this Fire (as all Things which are endued with it are) then the Cells would not have remained so intire as the wonderful Architects left them.

As concerning the Silk, I look on it as an excrementitious Matter also; designed by God Almighty (who makes nothing in vain) to become a Capsula or Coffin to preserve the Insect in it safely, for such a Season as was intended it should remain there.

All resinous Bodies are likewise non-electricable; which I think will tend rather to prove my Conjecture to be true than false: For, are there such Things as Pitch or Resin in Nature? Are they not made out of the Juice of Plants? Which Plants, whilst they remained in the Life of Nature, had nothing but their unalter’d Juice in them. Pitch and Resin became so by Art; and therefore no Time or Chance can give an Increase to their Quantity: From whence they may be supposed not to be in the Course of Nature.

I am aware what Objection this is liable to; for, though it must be acknowleg’d that these Things are non-electricable, it may be asked, If they are not the most inflammable Things that can be imagined, and, consequently, susceptible of Fire; because Candles are made out of Wax, and Torches out of Pitch and Resin? To which I answer, That here it may be necessary to inquire, what occasions this Flame, which is produced either from the Candle or Torch? Can this Flame subsist one Moment, without the Passage of Air through it? I answer, No. Well then, as this Treatise is not intended merely to state Facts, but to account for the Nature of them, by the best Conjectures I can make, pray why does Air keep this Flame subsisting? If you will suppose, with me, that the Cause of all Heat, and the Appearance of all Fire in the World, is collected out of this universal Element of Fire; which, perhaps, will never increase nor diminish; it being dispersed where it is most invited; if therefore, I say, you will suppose with me, that this Air, which is full of a lambent Flame, when it has been invited by the Property supposed to be in it, that the biggest Body congregates the less; from these Considerations, I think it may be supposed, that the Flame of Fire is produced out of the Air, only; the Wax or Resin being a fatty sulphureous Matter, which, as Coals, may likewise be supposed to serve as a Pabulum, fitly adapted only to let this Element pass through it, for the Purposes here described.

The more of the Air that passes through them, the quicker they burn; as when the Snuff of a Candle is taken off, which hindered the Quantity to pass thro’ it, it increases the Flame; though, before, the same Materials were employ’d. The same may be said of clearing the Ashes from, and stirring the Fire; which impeded the Quantity of Air from leaving its Fire behind, in its Passage through the Coals.

If the Wax had any Inherency of Fire in its Nature, Why, if you turn a lighted Candle downwards, does the Wax extinguish the Flame? If this my Conjecture be difficultly conceiv’d, pray let me farther ask, Why does a Candle, which is lighted, and let down into a Mine where there is a Damp, go out? In a large Mine there is Space enough surely for a Candle to burn in, if there had been enough of that Pabulum Vitæ left in the stagnated Air which occupy’d that large Cavern.

Now, if you will suppose, with me, that this Air had been robb’d of its Fire, by its supporting and keeping alive such Things under-ground as its Business is to do every-where, and that Space was left full of stagnated Air, and therefore could not admit of fresh to enter, it became impossible for Fire, or any living Creature, to subsist there.

The Cure of this Evil is performed in Mines by a Horse-Mill, which works large Bellows, that drive fresh Air down a Shaft made for that Purpose.

I remember Dr. Halley told me, that he once try’d the Experiment of making a factitious Damp; which he did, by exhausting the Air out of the Receiver of an Air-Pump, and then luting to a Stop-cock a Gun-barrel; the other End of which he put into a Charcoal-Fire, and with the Air, which pass’d thro’ the Fire, he fill’d the Receiver again; he told me that it instantly kill’d a Mouse he put into it, and many other Animals, just as Damps did: Now how will you account for this, if you suppose not that its Fire was extinguish’d, and carried from it another Way?

Having thus far, I hope, prepared your Mind to understand what I apprehend the Element of Fire is, and what its Office seems to be, I will shew, if I can,

First, Why, in Electricity, Fire proceeds from an electrical Body, so as to light into a Flame many different Compositions.

Secondly, Why a Tube of Glass, when rubbed so as to be made electrical, will not only attract to it, but repel from it alternately, any light Body, as Leaf-Gold, Feathers, and the like: And also, why it will seem to send from it a Quantity of Wind, with a singing small Noise, if you hold it nigh to your Cheek and Ear.

Thirdly, Why, when any unelectrify’d Body touches any thing electrify’d, the Electricity breaks off with a smart Crack, and a Spark of Fire.

Fourthly, Why a Number of Men, who are joined together by holding any metallic Body betwixt them, if one of them touch a Piece of Iron electrify’d, the whole Company shall feel a violent Concussion, in proportion to the Largeness of the Body electrify’d.

First, I will endeavour to shew, Why an electrify’d Body will kindle an Alcohol, or rectify’d Spirit of Wine, and many other compounded Liquors, into a Flame.

After having attempted to prove to you, that the Cause of Electricity arises from the universal Fire scatter’d through all Nature, by its being rubb’d together in its Passage betwixt a glass Ball and a Piece of Leather, &c. I hope I shall make it appear, that it passes from thence, to the Body electrify’d, in a converging and diverging State; just as a Lens converges and diverges the Rays of Light which pass through it: And that all Bodies electrify’d are shut up in a Capsula or Covering of this electric Matter, or lambent Flame, which not only passes over it about half an Inch thick, but pervades also every Part and Particle of Matter which constitutes that Body; which it may as easily do, if it consisted of many Tons Weight, as soon, and from the same Necessity, as it would do to one of an Inch Diameter: And that the electrify’d Body is intirely seal’d up at each Extremity.

To shew this Fire in a converging State, you may observe, when a Gun-barrel, or any long Bar of Iron, is to be electrify’d, and it is in a State of Suspension on silk Cords, which are non-electricable, you may perceive the Fire issue from a Piece of iron Wire coming from the glass Ball, in a lambent Flame, which draws to a Point, and then diverges, and drives itself on, till the Gun-barrel, or Bar, is electrify’d.

Its being a Gun-barrel can be no other Reason for its Preference in that Shape than in another; but I believe the Occasion of its being used here is, because the greatest Effect which has been shewn from Electricity, was sent from abroad; and that was caused by suspending a great Gun in a non-electricable silk Cord. The Gun seems to have been made use of here as being the greatest Quantity of Iron, and in the best Shape, they could get it for Suspension. And were a Person so suspended, if he held in his Hand a naked Sword, you might see such a lambent Flame passing from it, in a converging and diverging State, as before describ’d.

I would further prove this converging Fire, from a late Experiment I have heard of, which is as follows: If you suspend an iron Ball by a large Piece of Wire, which descends from a Bar of Iron electrify’d, and then hold under it, in a Saucer, some small round Bubbles of Glass, near enough to be in Contact with the electrical Vortex, the glass Balls will follow each other round in the Saucer; and each of these Balls, if the Experiment be made in the dark, will appear to have a Spot of blue Flame at each End of them.

Now, as, by the Contrivance of Man, here is more of this Fire crouded together, than was intended by the Author of all Uniformity, seeing, by its natural Cohesion, and the infinite Celerity it is spirally driven on with, it is no Wonder, in this confined State, if that, which, as Water unconfin’d, would be gentle and beneficent, should, with all the Power that belongs to it, break out at the first Door which is opened for its Passage from this tortur’d State.

It is no Wonder, therefore, that all undisorder’d Nature should be equally electrify’d: For how is it possible to have it otherwise? since, if a Person stands on the Ground, and touches but the Capsula before he touches the Body, the electric Fire starts through him into the Ground, as swift as Lightning, and thence into the universal lambent Flame, from whence it was taken.

Lightning from hence may in some measure be accounted for; though I cannot so exactly tell what collects it together, as I can in this factitious Lightning here treated of, yet I can suppose, that the Cause of Lightning is produc’d from a great Quantity of this Fire before spoken of; which being driven together, and included in a limited State, or Covering of some Kind, when discharged from this Covering, it goes off in an Explosion, which is Thunder. The Lightning I need not describe, being intirely the same with Electricity; for it will kill without a Wound, and pass through every thing, as this seems to do.

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