The desideratum: or, electricity made plain and useful. By a lover of mankind, and of common sense:

THE DESIDERATUM: OR ELECTRICITY made PLAIN.

I. 1. FROM a thousand Experiments it ap∣pears, that there is a fluid far more subtle than Air, which is every where diffused thro' all Space, which surrounds the Earth and pervades every Part of it. And such is the extreme Fine∣ness, Velocity and Expansiveness of this active Principle, that all other Matter seems to be only the Body, and this the Soul of the Universe. This we might term Elementary Fire; but that it is hard for us to separate the Ideas of Fire and Burning: Altho' the latter is in reality but a preternatural and violent Effect of the former.

2. It is highly probable this is the general Instru∣ment of all the Mo••ion in the Universe: From this pure Fire, (which is properly so called) the vulgar Culinary Fire is kindled. For in Truth there is but one Kind of Fire in Nature, which exists in all Places and in all Bodies. And this is subtle and active enough, not only to be, under the Great Cause, the secondary Cause of Motion, but to pro∣duce and sustain Life thro'out all Nature, as well in Animals as in Vegetables.

3. To this effect the learned Bishop of Cloyne observes, "The vital Flame is supposed to be the Cause of all the Motions in the Body of Man, whether natural or voluntary. And has not Fire the same Force to animate thro'out, and actuate the whole System of the World? Cherishing, heat∣ing, fermenting, dissolving, shining, and operating in various Manners, as various Subjects offer, to employ, or to determine it's Force? It is pre∣sent in all Parts of the Earth and Firmament, tho' latent and unobserved, till some Accident produces it into Act, and renders it visible in it's Effects."

4. This great Machine of the World requires some such constant, active and powerful Principle, constituted by it's Creator, to keep the heavenly Bodies in their several Courses, and at the same Time give Support, Life and Increase to the vari∣ous Inhabitants of the Earth. Now as the Heart of every Animal is the Engine which circulates the Blood thro' the whole Body, so the Sun, as the Heart of the World, circulates this Fire thro' the whole Universe. And this Element is not capable of any essential Alteration, Increase or Diminution. It is a Species by itself; and is of a Nature totally distinct from that of all other Bodies.

5. That this is absolutely necessary both to feed common Fire, and to sustain the Life of Ani∣mals, it seems may be learn'd from an easy Experi∣ment. Place a Cat, together with a lighted Candle, in a cold Oven: Then lute the Door close, having fixt a Glass in the Middle of it: And if you look thro' this, you may observe, at one and the same Instant, the Candle goes out, and the Animal dies. A plain Proof, that the same Fire is needful to sus∣tain both culinary Fire and animal Life: And a large Quantity of it. Some doubtless pervades the Oven Door; but not enough to sustain either Flame or Life. Indeed every Animal is a kind of Fire-Engine. As soon as the Lungs inspire the

Air, the Fire mingled with it is instantly dispers∣ed thro' the pulmonary Vessels into the Blood: Thence it is diffused thro' every Part of the Body, even the most minute Arteries, Veins and Nerves. In the mean Time the Lungs inspire more Air and Fire, and so provide a constant Supply.

6. The Air seems to be universally impregnat∣ed with this Fire, but so diluted, as not to hurt the Animal in Respiration. So a small Quantity of a Liquor dropt in Water, may be friendly to an human Body, tho' a few Drops of the same Li∣quor, given by themselv••s, would have occasioned certain Death. And yet you cannot conceive one Particle of the Water, without a Particle of the Medicine. 'Tis not impossible, this may be one great Use of Air, by adhering so closely to the elementary Fire, to temper and render salutary to the Body, what would otherwise be fatal to it.

7. To put it beyond dispute, that this Fire is largely mixt with the Air, you may make the fol∣lowing Experiment. Take a round Lump of Iron, and heat it to a Degree called a welding Heat: Take it out of the Fire, and with a Pair of Bel∣lows blow cold Air upon it. The Iron will then as effectually melt, as if it were in the hottest Fire. Now when taken out of the Forge, it had not Fire enough in it to conquer the Cohesion of it's Parts: But when this Fire is join'd with that which was mixt with the Air, it is sufficient to do it. On the same Principle we account for the Increase of a Coal or Wood Fire by blowing it.

8. And let none wonder that Fire should be so connected with Air, as hardly to be separated. As subtle as Fire is, we may even by Art attach it to other Bodies; yea, and keep it Prisoner for many Years: And that either in a solid or a fluid Form. An Instance of the first we have in Steel: Which is made such, only by impacting a large Quantity of Fire into Bars of Iron. In like Manner we

impact a great Quantity of Fire into Stone, to make Lime. An Instance of the second Kind we have in Spirits, wherein Fire is imprison'd in a fluid Form. Hence common Spirits will burn all away. And if you throw into the Air Spirits rec∣tified to the highest Degree, not one Drop will come down again, but the universal Fire will take hold of and absorb it all.

9. That this Fire subsists both in Air, Earth, and Water; that it is diffused thro' all and every Part of the Universe, was suspected by many of the antient Naturalists, and believed by the great Sir Isaac Newton. But of late Years it has been fully demonstrated: Particularly, by Mr. Stephen Gray, a Pensioner at the Charterhouse; who some Years since presented to the Royal Society, an Account of many Experiments he had made, whereby this subtle Fluid became clearly perceptible both to the Sight and Feeling. Because the Glass Tube, by Means of which those Experiments were made, was observed when rubbed to attract Straws and other light Bodies (a known Property of Amber, called in Latin Electrum) these Experiments were termed electrical: A Word which w••s soon affixt to that subtle Fluid itself, and every Thing pertaining to it. But improperly enough: Seeing the attracting (or seeming to attract) Straws and Feathers, is one of the most inconsiderable of all the Effects, wrought by this powerful and uni∣versal Cause.

10. It was afterwards found, that a Glass Globe was on some Accounts preferable to a Glass Tube: Particularly, as it was less Labour to turn the one for some Hours together, by means of a small Wheel, in the mean Time rubbing it with a dry Hand, or a little Cushion, than to rub the Tube for so long a Time. It w••s likewise ob∣served, that a greater Quantity of ethereal Fire might be collected by this Means than by the other.

I say collected; for that Fire is no more created by rubbing, than Water is by pumping. The grand Reservoir thereof is the Earth, from which it is diffused thro' all the other Parts of common Mat∣ter. Accordingly in these Experiments, the Globe rubbing against the Cushion, collects Fire from it. The Cushion receives it from the Frame of the Machine; the Frame of the Machine from the Floor. But if you cut off the Communication with the Floor, no Fire can be produced, because none can be collected.

11. In the Year 1746, Mr. de Muschenbroek, Prof••ssor of natural Philosophy at Leyden, was led by a casual Experiment, into many new Discove∣ries. These were chiefly made by Means of a large but thin Glass Phial. The best way to pre∣pare which is, to coat it with thin Lead; to line it on the inside with Leaf-Gold, to within two Inches of the Top, and to fasten some Tinsel Fringe to the Bottom, (or to the End of the Wire within the Phial) so as to touch the Gold Lining. By this Wire going thro' the Cork, the Phial is hung on any metallic Body, which communicates by a Wire, with the Globe or Tube. This metallic Body has been term'd, the prime Conductor, as it conducts or conveys the Fire collected by the Tube or Globe, either into the Phial, or into any other Body communicating therewith.

12. But all Bodies are not capable of receiving it. There is in this Respect an amazing Differ∣ence between them. The Excrements of Nature, as Wax, Silk, Hair, will not receive the ethereal Fire, neither convey it to other Bodies: So that whenever in circulating it comes to any of these, it is at a full stop. Air itself is a Body of this Kind; with great Difficulty either receiving or conveying this Fire to other Bodies: So are Pitch and Rosin (Excrements, as it were, of Trees). To

these we may add Glass, Amber, Brimstone, dry Earth, and a few other Bodies. These have been frequently stiled Electrics per se; as if they alone contain'd the electric Fire: An eminently improper Title, founded on a palpable Mistake. From the same Mistake, all other Bodies, which easily re∣ceive and readily convey it, were term'd Non elec∣trict; on a Supposition, that they contain'd no electric Fire: The contrary of which is now al∣low'd by all.

13. That this Fire is inconceivably subtle, ap∣pears from it's permeating even the densest Me∣tals, and that with such Ease, as to receive no per∣ceptible Resistance. If any one doubt, whether it pass thro' the Substance, or only along the Surface of Bodies, a strong Shock taken thro' his own Bo∣dy, will prevent his doubting any longer. It dif∣fers from all other Matter in this, that the Par∣ticles of it repell, not attract, each other. And hence is the manifest Divergency in a Stream of electrical Effluvia. But tho' the Particles of it re∣pell each other, yet are they attracted by all other Matter. And from these thr e, the extreme sub∣tlety of this Fire, the mutual Repulsion of its Parts, and the strong Attraction of them by other Mat∣ter, arises this Effect, that if a Quantity of elec∣tric Fire be applied to a Mass of common Matter of any Bigness or Length, (which has not already got its Quantity) it is immediately diffused thro' the whole.

14. It seems, this Globe of Earth and Water, with its Plants, Animals, Buildings, have diffused thro' 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 of 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 solid Foot of another Kind. And a Pound Weight of the same Kind of Matter, when rare∣fied, contains more than it did before.

15. We know that this Fire is in common Matter, because we can pump it out, by the Globe or Tube: We know that common Matter has near as much of it as it can contain, because if we add a little more to any Portion of it, the addi∣tional Quantity does not enter, but forms a Kind of Atmosphere round it. On the other Hand, we know that common Matter has not more of it than it can contain. Otherwise all loose Portions of it would repel each other; as they constantly do, when they have such Atmospheres. Had the Earth, for Instance, as much electric Fire in Proportion, as we can give to a Globe of Iron or Wood, the Particles of Dust and other light Matter, would not only repel each other, but be continually re∣pelled from the E••rth. Hence the Air being con∣stantly loaded therewith, would be unfit for Re∣spiration. Here we see another Occasion to adore that Wisdom, which has made all Things by Weight and Measure.

16. The Form of every electric Atmosphere, is that of the Body which it surrounds: Because it is attracted by every Part of the Surface, tho' it can∣not enter the Substance already replete. Without this Attraction, it would not remain round the Bo∣dy, but dissipate into the Air.

17. The Atmosphere of an electrified Sphere, is not more easily drawn off, from any one Part of it than from the other, because it is equally at∣tracted by every Part. But it is not so with Bo∣dies of other Figures. From a Cube it is more easily drawn off at the Corners than 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 Body re∣tains

it's Atmosphere, is proportion'd to the Sur∣face on which that Atmosphere rests. So a Sur∣face four Inches square retains it's Atmosphere, with sixteen Times the Force that one of an Inch square does. And as in pulling the Hairs from an Horse's Tail, a Force insufficient to pull off an Handful at once, could easily pull it off Hair by Hair: So tho' a blunt Body can't draw off all the Atmosphere at once, a pointed one can easily draw it off, Particle by Particle.

18. If you would have a sensible Proof, how wonderfully pointed Bodies draw off the electric Fire, place an Iron Shot of four Inches Diameter on the Mouth of a dry Bottle. Suspend over it a small Cork-Ball by a silken Thread, just so as to rest against the Side of the Shot. Electrify the Shot, and the Ball will be repelled four or five Inches from it. Then present to the Shot six or eight Inches off the Point of a sharp Bodkin. The Fire is instantly drawn off; so the Repulsion ceases, and the Ball flies to the Shot. But a blunt Body will not produce this Effect, till it is brought with∣in an Inch of the Shot. If you present the Point of the Bodkin in the Dark, you may see some∣times at a Foot Distance, a Light gather upon it like a Glow-worm, which is manifestly the Fire it extracts from the Shot. The less sharp the Point is, the nearer it must be brought, before you can see the Light. And at whatever Distance you see the Light, you may draw off the electric Fire.

19. To be convinced that pointed Bodies throw off, as well as draw off the Fire, you may lay a long sharp Needle on the Shot. It cannot then be electrified, so as to repel the Ball, because the Fire thrown upon it, continually runs off, at the Point of the Needle: From which in the Dark you may see such a Stream of Light, as in the preceeding Instance.

20. While the electric Fire, which is in all Bo∣dies, is left to itself, undisturb'd by any external Violence, it is more or less dense, according to the Nature of the Body which it is in. In dense Bo∣dies 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 it's Nature. And there is some Resistence to every Endeavour of altering it's Density, in the whole of any Body, or in any Part of it. For all Bodies resist either the Increase or Diminution of their natural Quan∣tity. And on the other Hand, when it has been either increased or diminished, there is a Resistence to it's Return to it's natural State.

21. With regard to the different Resistence made by different Bodies, in either of these Cases, it is an invariable Rule, that Glass, Wax, Rosin, Brim∣stone, Silk, Hair, and such like Bodies, resist the most: And next to these, the Air, provided it be dry, and in a sufficient Quantity. That this Re∣sistence is least in Metals, Minerals, Water, Quick∣silver, Animals and Vegetables: Which we may rank together, because the Difference in their Re∣sistence is very inconsiderable: And that in these Bodies the Resistence is greater, when their Sur∣face are polish'd, and extended in length, than when their Surfaces are rough and short, or end in sharp Points.

22. When a Body has more electric Fire forced into it, than it has naturally, it is said to be elec∣tified positively. When Part of the natural Quanti∣ty is taken away, it is said to be electrified negative∣ly. Now when an Iron Bar is negative'y electrified, the Fire drawn out, does not go in again as soon as the Experiment is over, but forms an Atmos∣phere round it, because of the Resistence it finds in it's Endeavour to dilate itself, either into the Air or into the Bar. And when it is electified positively,

the same Kind of Atmosphere is form'd, by the Fire accumulated upon it. Whether therefore Bo∣dies are electrified negatively or positively, and re∣main so when the Experiment is over, there are si∣milar Atmospheres surrounding them, which will produce similar Effects.

23. But we can electrify no Body beyond a cer∣tain Degree: Because when any is electrified to that Point, it has an Atmosphere round it sufficient∣ly strong to ballance any Power that endeavours to electrify it farther. Nor is the electric Fire either from the Tube or the Globe, able to force its Way thro' this.

24. And in the ordinary Course of Nature, this subtle, active Fluid, which not only surrounds eve∣ry gross Body, but every component Particle of each, where it is not in absolute Contact with it's neighbouring Particle, can never be idle, but is ever in Action, tho' that Action be imperceptible to our Senses. It is ever varying it's Condition, tho' imperceptibly, in all Parts of all Bodies what∣ever; and electrifying them more or less, tho' not so forcibly as to give sensible Signs of it. All Bo∣dies then, and all their component Particles, when in their natural Situation, have round their Surfa∣ces, where they are not in absolute Contact with other Surfaces, an imperceptible Atmosphere suffi∣cient to ballance the smaller Force with which they are attack'd: 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 the Elasticity of the subtle Fluid, every where dispersed both round all Bodies and in them.

25. Glass is very difficultly electified, which seems 〈◊〉〈◊〉 prove it has a very dense electric Atmosphere.

Metals are easily electrified. Consequently they have rare and therefore weakly-resisting Atmos∣pheres. 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 Resistence than Water. But it's Resistence increases, as it cools. And when it is quite cold, it resists as forcibly as ever. Smoothly-polish'd Wax resists as much as Glass. But even the small Heat raised by rubbing, will render it's Atmosphere as rare as that of Me∣tals, and so intirely destroy it's Resistence. The same is true of Rosin and Brimstone. Even the Heat arising from Friction, destroys the Resistence which they naturally make to being electrified: A strong Proof, that the Resistence of all Bodies there∣to, is exerted at their Surfaces, and caused by an electric Atmosphere of different Densities, accord∣ing to different Circumstances.

26. Most Experiments will succeed as well with a Globe of Brimstone, as with one of Glass. Yet there is a considerable Difference in their Nature. What Glass repells, Brimstone (as also Rosin) at∣tracts. Rubbed Glass emits the electric Fire: Rubbed Brimstone, Rosin and Wax receive it. Hence if a Glass Globe be turned at one end of a prime Conductor, and a Brimstone one at the other, not a Spark of Fire can be obtain'd; one receiving it in, as fast as it is given out by the other. Hence also if a Phial be suspended on the prime Con∣ductor, with a Chain from it's Coating to the Ta∣ble, and only one Globe turned, it will be elec∣trified (or charged, as they term it) by twenty turns of the Wheel: After which it may be discharged, that is, unelectrified, by twenty Turns of the other Wheel.

27 The Difference between Non Electrics (vul∣garly speaking) and Electrics per se, is chiefly this. 1. A Non Electric easily suffers a Change, in the Quantity of Fire it contains. It's whole Quantity may be lessen'd by drawing out a Part, which it will afterwards resume. But you can only lessen the Quantity contain'd in one of the Surfaces of an Electric: And not that, but by adding at the same Time an equal Quantity to the other Surface. So that the whole Glass will always have the same Quantity in it's two Surfaces And even this can only be done in Glass that is thin: Beyond a cer∣tain Thickness we know no Power that can make this Change. 2. The ethereal Fire freely moves from Place to Place, in and thro' the Substance of a Non Electric. But thro' the Substance of an Electric it will by no Means pass. It freely en∣ters an Iron-Rod, and moves from one End to another, where the Overplus is discharged. But it will not enter, or move thro a Glass-Rod. Nei∣ther will the thinnest Glass which can be made, suffer any Particle of it entering one of it's Sur∣faces, to pass thro' to the other.

28. Indeed it is only Metals and Liquids, that perfectly conduct (or transmit) this Fire. Other Bo∣dies seem to conduct it, only so far as they contain a Mixture of these; accordingly, moist Air will con∣duct it, in Proportion to it's Moistness. 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's dissipating (which it does presently when in vacuo) or passing from Body to Body. A clear Bot••le full of Air, instead of Water, can∣not be electrified. But exhausted of Air, it is elec∣trified as effectually as if it was full of Water. Yet an Electrical Atmosphere and Air, do not ex∣clued one another. For we breath in it freely,

and dry Air will blow thro' it, without altering it at all.

29. When a Glass Phial is electrified, whate∣ver Quantity of Fire is accumulated on the in∣ner Surface, an equal Quantity is taken from the outer. Suppose, before the Operation begins, the Quantity of Fire contain'd 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, nine∣teen only without: After the second, the inner Sur∣face will have twenty-two, the outer but eighteen: And so on, till after twenty Strokes, the inner will have forty, the outer none. And the. Opera∣tion 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 in, it is thrown back thro' the Wire, or flies cut in Cracks thro' the Sides of the Phial. The Equilibrium cannot be restored in this Phial, but by a Communication form'd between the inner and outer Surface, by something 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 thro' the Body, in it's Way from the inner to the outer Surface. For it moves from the Wire to the Fin∣ger, (not from the Finger to the Wire, as is commonly supposed). Thence it passes thro' the Body to the other Hand, and so to the outer Sur∣face.

30. The Force with which this Shock may be given, is far greater than one would conceive. It will kill Rats, Hens, or even Turkeys in a Mo∣ment: Others, that are not quite killed, it strikes blind. It will give Polarity to a fine Needle, mak∣ing

it point North and South, as if touched by a Loadstone. It will invert the Polarity of a Com∣pass, and make the North Point turn to the South. At the same Time the Ends of the Needles are fine∣ly 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 blister'd, when examined by a magnifying Glass. It will melt thin Gold or Sil∣ver, 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 thro' a Quire of Paper doubled: Which is thought good Armour against the Push of a Sword, or even a Pistol Bullet. And 'tis 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, part∣ly 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 this small Glass! It seems to be a Part of it's 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 Properties, it's Transparency▪ Brittleness, and Elasticity.

31. Some have not improbably supposed, that all Electric Bodies, so called, are by their original Con∣stitution, thro'ly saturated with Electric Fire: That it remains fixt in them, (unless while the Texture of those Bodies is quite alter'd by Liquefaction) that Fire fixt in a Body constitutes an Electric, and all Bodies where it is not fixt are Non Electries. Agreeably to which they suppose that in all Non Electrics, the Original Fire, loosely inhering, is easily driven on by the new collected Fire, which

then possesses its Place: But that in Electrics the Original Fire being impacted into their Substance, and therefore more firmly inhering, will not give Way to, or be driven on by, the new collected Fire. Such is Air in particular; 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: Where∣as all n••w-collected Fire is continually endeavour∣ing to return into the Earth. Let Wires be elec∣trified ever so strongly, yet the Moment any Part of them is touch'd by a Person standing on the Floor, they are electrified no longer; all the Fire escaping thro' him into the Earth.

32. Upon the Principles of Electricity, we may give a more rational Account, of many Appearan∣ces in Nature, than has yet been done: Of Thun∣der and Lightning in particular. In order to which we may observe, all electrified Bodies retain the Fire thrown into them, till some Non-electric ap∣proaches: To which it is then communicated with a Snap, and becomes equally divided. Electric Fire 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 Fire, till they meet with Clouds not so much electrified. Then they communicate it with a Shock.

33. 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 failing Vessel. It appears from every Dash of an Oar: In Storms the whole Sea seems on Fire. The Particles of Water then repell'd from the electrified Surface, continually carry off the Fire as it is col∣lected. They rise and form Clouds which are high∣ly

electrified, and retain the Fire till they have an Opportunity of discharging it.

34. Particles of Water rising in Vapours, attach themselves to Particles of Air. One Particle of Air may be surrounded by twelve Particles of Water as large as itself, all touching it, and by more added to them. Particles of Air thus loaded would be drawn nearer together by the mutual Attraction of the Particles of Water, did not the Fire, Common or Electric, included therein, assist their mutual Repulsion. Hence they continue suspended. But if Air thus loaded, be compress'd by adverse Winds, or by being driven against Mountains, or if it be condensed by the Loss of it's Fire, it will continue suspended no longer, but will descend in Dew. And if the Water surroun ing one Particle of Air comes into contact with that surrounding another, they naturally coalesce into a Drop, and so descend in Rain.

35. The Sun supplies common Fire to all Va∣pours, rising either from Sea or Land. Vapours having both this and Electric Fire, are better sup∣ported than those which have this only. For when Vapours rise into the coldest Region, the common Fire may fail. But the Cold will not diminish the Electric: This is always the same. Hence Clouds raised from fresh Waters, from moist Earth, or growing Vegetables, more easily descend and de∣posite their Waters, as having but little Electric Fire, to keep the Particles separate from each other. So that the greatest Part of the Water raised from the Land, falls on the Land again. But Clouds raised from the Sea, having both Fires, and much of the Electric, support their Water far more strong∣ly, and being assisted by Winds, may bring it from the Middle of the widest Ocean to the Middle of the broadest Continent. And yet a Way is pro∣vided whereby these also are readily brought to de∣posite

their Water. For whenever they are driven against Mountains by the Winds, those Mountains take away their Electric Fire: And being cold, the common also: Hence the Particles immediately close. If the Air was not much loaded, the Water falls in Dew on the Top and the Sides of the Mountain. If it was, the Electric Fire being taken at once from the whole Cloud, it flashes brightly, and cracks loudly. And the Particles instantly coales∣cing for want of that Fire, fall in an heavy Shower.

36. When a Ridge of Mountains stops the Clouds, and draws the Electric Fire from the Cloud first approaching it, the next when it comes near the first, now deprived of it's Fire, flashes into it, and deposites it's own Water. The third Cloud approaching, and all that succeed, act in the same Manner; as far back as they extend, which may be for several hundred Miles. Hence the continual Storms of Thunder, Lightning and Rain, on the East Side of those va••t Mountains, the Andes, which running North and South, intercept all the Clouds brought against them from the Atlantick Ocean. In a plain Country, there are other Means to make them drop their Water. For if an electrified Cloud coming from the Sea, meets in the Air a Cloud coming from the Land, and therefore not electri∣fied, the first will give it's Flash into the latter, and thereby both will be made to deposite their Wa∣ter. 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 far beyond the flashing Distance. And yet where a Cloud contains much Fire, it may strike at a considerable Distance. When a Con∣ductor

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 Bar∣rel, when electrified, will strike and make a Noise, at the Distance of an Inch, at what a Distance, and with how great a No••se, may ten thousand Acres of electrified Cloud strike? No Wonder that this should melt Metals (which our artificial Flash does in some Degree) tho' perhaps not so properly by it's Heat, as by insinuating into the Pores, and cre∣ating a violent Repulsion between the Particles of the Metal it passes thro'. This overcomes the At∣traction whereby they cohere, and so melts the me∣tallic Body. And this accounts for its melting a Sword in the Scabbard, or Gold in the Pocket, without burning either.

37. But Thunder Clouds do not always contain more than their natural Quantity of Electric Fire. Very frequently they contain less. And when this is the Case, when they are negatively electrified, altho' 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 Part 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 nega∣tively electrified. When a Portion of Water is rare∣fied into a thin Vapour, the Fire it contains is rare∣fied too. Consequently it has then less than it's 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 of∣ten contain a great Quantity of Fire. Such a Cloud also passing over Woods of tall Trees, may silently receive some Supply, either from the Points of the

Boughs, or from the sharp 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 in Showers to the Earth, their Original. Rain, especially when in large Drops, generally brings down the Electric Fire: Falling Snow often: Summer Hail, always, tho' silently. Consequently, any of these may prevent Thunder and Lightning; or at least, abate it's Violence. Rain is helpful in another Respect like∣wise. By wetting Men or Beasts, it saves many Lives. For if your Cl athes are thro'ly wet, and a Flash of Lightning strikes the Top of your Head, it will run in the Water over the Surface of your Bo∣dy into the Ground: Whereas if your Cl aths were not wet, it would go thro' your Body. Hence a wet Chicken cannot be killed by a Stroke from the Phial; whereas a dry one is kill'd in an Instant. See here also the Wisdom and Goodness of Him, who sendeth forth Ligh••ning•• with the Ra••n! It should likewise be observ'd, that wherever electrifi∣ed Clouds pass, Spires, Towers, Chimneys, and high Trees, as so many Points, draw the Electric Fire, and the whole Cloud frequently discharges there Therefore it is highly dangerous in such a Storm, to take Shelter under a Tree.

38. Common Fire (if it be any thing more, than a different Modification of the same Element) is more or less in all Bodies, as well as Electrical. If there be a sufficient Quantity of either in any Bo∣dy, it is inflamed. But when the Quantity of com∣mon Fire therein is small there needs more Elec∣tric Fire to infl••me it. Where the Quantity of common Fire is greater, less of the Electric will suffice. So if Spirits are heated, a small Spark in∣flames

them. If they are not, the Spark must be greater. Sulphureous Vapours, whether rising from the Earth, or from Stacks of moist Hay or Corn▪ or any other heated and reeking Vegetable, contain ab ndance of common Fire. A small Ad∣dition of Electric then will inflame them. There∣fore they are easily kindled by Lightning.

39. Any who would be clearly convinced of the Nature of Lightning, may make the following Ex∣periment. 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 of the Cross; and so you have the Bo∣dy 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 fi••ter to bear the Wind and Wet in a Storm without tearing. To the Top of the Cross fix a sharp pointed Wire, rising a Foot above it. Tie a Silk Ribbon to the End of the Twine next the Hand; and where the Silk and Twine join, fasten a Key. Raise this Kite when a Thunder-Storm is coming on: But he that holds the String, must stand in a Porch, or under some other Covering, that the Ribbon may not be wet. He must likewise take particular Care, that the Twine do not touch the Top or Side of the Porch. As soon as the Thunder-Cloud comes over the Kite, the pointed Wire draws the Electric Fire from it. The Kite and all the Twine are then electrified, as plainly appe••rs by this, that the loose Filaments of the Twine stand out every way, and are attracted by an approaching Finger. And when the Kite and Twine being wet, conduct the Fire freely, it will stream from the Key, on the Ap∣proach of the Knuckle. By this Key the Phial may be charged, and all other Experiments made, as by the Globe. And this is a Demonstration,

that the Electric Fire thereby obtain'd, is the very same with that of Lightning.

40. May not the Knowledge of this Power in pointed Bodies, of drawing off the Fire contain'd in these Clouds, suggest to us a very probable Me∣thod, of preserving ••ouses, Churche••, Ships from the Stroke of Lightning? Might we not fix on the highest Part of them, upright Rods of Iron made sharp as Needles, and gilt, to prevent rust∣ing, which otherwise would hi der their free Con∣veyance of the Electric Fire? From the Foot of those Rods (which need not be above half an Inch diameter) a W••re may pas•• down the Outside of the Building into the Ground; or down ••ound one of the Shrouds of a Ship, and down her Side, till it reaches the Water. Would not these Rods si∣lently draw off ••he Electric Fire, before the Cloud was nigh enough to strike? And thereby in a good Measure secure us from that most sudden and terri∣ble Mischief! Let it not be objected, that the us∣ing this probable Means of preventing a threatning Danger, would imply any Denial of, or Distrust in, Divine Providence Not at all: We know the Creator of the Universe, is likewise the Go∣vernor of all Things therein. But we know like∣wise that he gove ns by second Causes; and that accordingly it is his Will, we should use all the probable Means he has given us, to attain every lawful End. It is therefore no more an Impeach∣ment of his Providence, when we foresee a Storm of Lightning and Rain, to shelter our House (as far as we are able) from the one, than to shelter our∣selves in that House from the other. Is it not just as innocent (if it be possible) to keep our Rooms tight from Lightning, as from Wind and Water?

41. It may not be improper to add one or two Observations, before we proceed to what is of more Importance. Scarce any Phenomenon in Nature

has been esteem'd more difficult to be accounted for than those luminous Appearances in the Sky, term'd Aurora Borealis, or Northern Lights. But these al∣so may be rationally explain'd, upon the Principles of Electricity. We often see Clouds at different Heights, passing different Ways, North and South at the same Time. This manifestly proves differ∣ent Currents of Air, one of them under the other. Now as the Air between the Tropics is rarefied by the Sun, it rises; the denser Air pressing into it's Place. The Air so raised, moves North and South, and if it has no Opportunity before, must descend in the Polar Regions. When this Air with it's Va∣pours descends into contact with the Vapours aris∣ing there, the Electric Fire which it brought be∣gins to be communicated, and is seen in clear Nights; being first visible where it is first in Mo∣tion, namely in the most Northern Parts. But from thence the Streams of Light seem to shoot Souther∣ly, even to the Zenith of Northern Countries.

42. Another Phenomenon of a totally different Kind, may be accounted for on the same Princi∣ples, altho' Mr. Prior supposes Solomon himself to ask, as a Question which he could not answer,

"Whence does it happen, that the Plant which well We name the Sensitive, should move and feel? Whence know her Leaves to answer her Command, And with quick Horror fly the neighbouring Hand?"

Allowing for Poetical Amplification the plain Fact is this. The Sensitive Plant, as it were, shrinks away, as soon as your Hand approaches it. And from a turgid and vivid Appearance, instantly droops and hangs it's Leaves. Now suppose this Plant to contain more Electric Fire than any other Plant or

Animal, it must or Course communicate that Fire, to any other that touches it. And if so, it's Leaves and Branches must be in a languid State, till they have recover'd their natural Quantity. To illustrate this, set any small Tree in a Pot on a Cake of Brimstone. Electrify it and it grows extremely turgid, so as to erect it's Leaves. But the Mo∣ment you touch one of them, the whole Tree droops, and hangs all it's Leaves and Branches.

To throw all the Light I can on the Subject, I subjoin a few Extracts from several other Writers.

An Extract from Mr. Watson's Experiments and Observations.

1. When two Plates, the one electrified, the other not, were brought near each other, the Flash∣es of bright Flame were so large, that in a dark Room, I could distinctly see the Faces of 13 Per∣sons. P. 6.

2. A Piece of large blunt Wire was hung to the Conductor. To the End of this when electrified a black Surface not electrified being brought near, (tho' not near enough to cause a Snap) a Brush of Blue Flame, quite different from the former, issued of more than an Inch long, and an Inch thick. P. 7.

3. If a Person strongly electrified lays his Hand on the Cloaths of one that is not, especially if they are thin Woollen or Silk, they both feel as it were many Pins pricking them, as long as the Globe is in Motion.

4. If Oil of Turpentine be set on Fire in a Ves∣sel held by one electrified, the Smoke arising there∣from, received against a Plate held at a Foot Dis∣tance from the Flame, by one standing on Rosin, will enable him to Fire warm Spirits of Wine. The Electric Strokes have been likewise felt, upon touching the second Man, when the Plate he held

in the Smoke has been between seven and eight Feet above the Flame. P. 8.

5. Take burning Spirits of Wine instead of Oil of Turpentine: And if the second Man hold the End of an Iron Rod at the Top of the Flame, he may k ndle other warm Spirits held near his Finger. Hence we find that either Smoke or Flame con∣ducts the Electric Fire, and does not perceptibly diminish it's Force. P 9.

6. If the Wire of the Phial be not touched, the electrified Water or Steel Dust will retain it's Force many Hours, may be convey'd several Miles, and will afterward exert it's Force upon touching the Wire. P. 16.

7. If an Egg is hung on the Conductor, and a Person grasping the electrified ••hial with one Hand, brings the Palm of his other near the Bottom of the Egg, he receives a smart ••troke on the Hand, as with a Ferula, and his Hand seems full of a more red Fire than is usually observed. P. 24.

8. Any Number of Persons communicating with each other, the first of whom grasps the Phial, and the last touches the Conductor, receive the same Shock as if it was ••ne only. P. 25.

9. The Electric Force always describes a Cir∣cuit, and moves in the straitest Line it can, be∣tween the Conductor and hial. P. 26

10. To prove th••s, while the Machine stood on Wax, I stood upon the Floor; and putting one Hand on the Machine, touch'd the Gun Barrel with the other. Upon this Fire issued, and the snapping continued as long as I held my hand on the Machine, but no longer This shew'd at once, that the Electric Fire past from the Floor thro' my Body t•• the Machine. P 36.

11. If the Electric Fire is ••ot stopt, no Sign of it's Presence is observable in the Bodies suspended to the Globe. Tho' it throws ever so much of this

Fire upon them, it passes from them to the Floor whence it came. But if it is stopt, it is then ac∣cumulated in or upon these Bodies: Altho' this can be done only to a certain Degree, after which it continually disperses. If when it is accumulated, a Man standing on the Floor touc••es those Bodies, the Snap is felt, and the Fire is seen. But this snapping is not▪ when the Fire passes off continual∣ly, as from a Piere of blunt Wire hung to the Barrel, and a Han•• brought near it. Then it ap∣pears li••e a blue Cone of Flame, with it's Point towards the Wire. When the Hand is held at a proper Distance▪ there is a Blast therefrom, as of cold Air. If you ••o not determine the Electric Fire to a Point, it is dispersed from all ••art•• of the electrified Body: But if you do, by thus holding your Hand near the Fire, you see ••ow it passes to the Floor, and so into the Earth. The Globe there∣fore only circulates this Fire, which is collected by it's Friction against the Hand or Cushion, and which is constantly supplied to these from the Earth. And accordingly the ••ngr••ss of it, as well as the Egress is visible. For, if while any unele••••rified Body touches the B••rrel, you bring your Finger near the Wood-Work of the Machine, you will see the Brush of Blue Flame set in from it to the Wood-Work. And this Flame passes diverging into the Machine, and continues as long as the Barrel is touched. P. 44.

12. That the Electric Atmosphere which sur∣rounds all electrified Bodies, extends to a consider∣able Distance, appears from their attracting a fine Thread, at the Distance of some Feet. If no un∣electrified Body is near, this Atmosphere seems to be equally spread over that which is electrified. But if one unelectrified is brought near, the greatest Part of it is determined that Way; whence the Attraction of the other Parts of the electrified Body

is considerably diminished. This is the Cause of Electric Repulsion, which does not operate, till the Electric Ether is sufficiently accumulated. This Repulsion is strongest in ••hose Parts of the electrified Body, where unelectrified Bodies are brought near it. For by these the Electric Blast, which otherwise is general, is particularly deter∣mined. P. 46.

13. When the Machine is placed upon Rosin, if a Man standing likewise on Rosin, touches the Barrel while the Globe is turning, he will receive a Snap or two, and no more. But if he touch the Wood-Work of the Machine with one Hand, and the Barrel with the other▪ he receives Snaps again, which continue as long as he touches the Machine, and no longer. Here the Man by touching the Machine with one Hand, becomes a Part thereof; and by turning the Globe, Part of the Electric Fire inherent in his Body, is transmitted to the Bar∣rel; but it is restored to him, on his touching the Barrel with his other Hand. If instead of touch∣ing the Machine or Barrel he holds his Finger near either, or both, you see the Fire go out and return. P. 64.

14. May we not gather from the preceeding Experiments, 1. That the Attrac••ion and Repul∣sion of electrified Bodies, is owing to the Flux of Electric Ether? 2. That this Ether is no other than pure Fire? 3. That this Fire appears in dif∣ferent Forms, according to it's different Modifica∣tions? When brought towards a Point is it not a lambent Flame? When nearer still, may we not both hear and feel it? And does not it's lighting up Spirits demonstrate, that it is real Fire? 4. That this Fire is intimately connected with all Bodies, tho' least of all with pure, dry Air? We have ex∣tracted it from Water, Flame, Smoke, red hot Iron; and from a Mixture 30 Degrees colder than

the freezing Point. 5. That it is extremely subtle and highly Elastic? 6. That the Electric Machine may as properly be term'd a Fire-Pump, as Mr. Foyl••'s Machine, an Air Pump? And lastly, that Fire is not Mechanically producible from other Bodies, but is an original, distinct Principle?

An Extract from Mr. Wilson's Dissertation on Elec∣tricity.

Prop. 1. When two Bodies equally replete with Electric Matter approach each other, no Flame or Snap will ensue. P. 5.

Prop. 2. Two Bodies equally electrified repel each other. P. 6.

Prop. 3. An Electric Body interposed between a Person and the Earth, prevents his exciting Elec∣tricity in another Body by Friction. P. 11.

Prop. 4. If there is originally a certain Quanti∣ty of Electric Matter in a Body of a given Mag∣nitude and Density; and that Matter be equally distributed therein, by it's Elastic Force, according to the Density of the Parts: Upon increasing the Quantity of Matter by adding other Bodies of the same Kind, the Quantity of Electric Matter will be increased in the same Proportion. P. 14.

Prop. 5. As Electric Bodies act on light Bo∣dies that are not electrified, so unelectrified Bodies act on the Electric Matter contain'd in electrified Bodies. P. 16.

Let a Wire be electrified in the Dark, and if you hold any unelectrified Body 7 or 8 Inches from the End of it, a Stream of Fire will issue from it, which will diverge to that Body. But the Diver∣gency will lessen as it approaches it, till the Rays become parallel. If the Body be held not directly before the End of the Wire, but wide of it at about two Inches Distance, the Fire will describe curvilinear Rays towards that Body. P. 17.

Hence it appears, that unelectrified Bodies act in like Manner with electrified: Only the acting Force of the one▪ being increased by Friction, is greater than that of the other.

Prop. 6. When two equally Electric Atmos∣pheres are brought so near as to touch, they repell each other with a Force equal to their Densi∣ties. P. 19.

Prop. 7. If while a Fluid surrounds a Globe which is electrified and turn'd round an Axis pas∣sing thro' it's Center, an unelectrified Body be held near the Equator of it, the Fluid will rise succes∣sively towards that Body, as it turns round, in like Manner as the Sea is affected by the Moon. P. 23.

The Shock given by the Phial is in Proportion to the Size of it, the thinness of the Glass, and the Number of Points in contact with it's Sur∣face. P. 25.

An Extract from Mr. Martin's Essay on Electricity.

1. The Electric Matter is emitted from some sort of Bodies when rubb'd, which are call'd Elec∣trics. P. 9.

2. By other Sorts of Bodies, therefore term'd Non-Electrics, it is not emitted.

3. It will run off to all Non-Electrics, but it re∣strained by all Electrics.

4. It shines like a Flame, and is emitted with a Snap: If towards a Non Electric, the Fire is con∣densed, less or more, and so appears of a bluish, Purple, Yellow, or White Colour.

When the Electric Fire is not so much condens∣ed as to explode, as in Thunder and Lightning it goes off in a dilated Stream of purple Flame, great∣ly resembling that Part of the Aurora Borealis, which appears in Streams of Light.

When it is little condensed, it appears bluish, as all other faint Lights do: When a little denser, it appears Purple: When denser still, it looks Yellow, like Candle Light: When highly condensed, it is clear and white, like the Light of the Sun. So the White Lightning is of all others most fierce. So Phosphorus rubb'd a little, spends itself in an harmless Blue Flame: But upon a greater Attriti∣on, kindles into a White Flame, and burns with an outragious and unquenchable Fire. p. 17.

And as Lightning pervades soft Substances un∣hurt, but dissolves hard and compact Bodies, so Electric Fire pervades the soft, muscular Parts of the Body, but violently strikes the Bones and Ten∣dons. Again, as those denser Parts of Lightning which we call Thunder-Bolts, striking against hard Bodies, glance by Reflection to different Parts, so this Fire, striking against the Elbow, is reflected from thence across the Breast, to the other El∣bow. p. 18.

Indeed different Persons are affected thereby in a very different Manner. Some are extremely ca∣pable of it, some not: And some are not suscep∣tible of it at all: A Person, for Instance, who has the Small-Pox, cannot be electrified by any Means whatever. p. 20.

Experiment 1. On the Axis, in the Center of my Globe, is fixt a circular String of Threads. When the Globe is at rest, they all hang down: When it is in Motion, they all extend themselves from the Center, strait toward the inner Surface of the Globe (like the Spokes of a Coach-Wheel) which they nearly touch. Thus they continue till the Electric Virtue ceases, and then gradually fall down, as at first. p. 22.

Exp. 2. While they are extended, if you move your Hand toward the Surface of the Globe, they move every Way toward the Hand. Hence we see

the amazing Subtlety of this Fire, which pervades Glass as readily as if nothing were in the Way.

Exp. 3. Place a Hoop of Fine Threads rou••d the Globe in Motion, and all of them will stand perpendicular to the Surface. Hence we learn that the Electric Power acts equally, both within and without the Globe, and in Directions perpendicu∣lar to it's Surface.

Exp. 4. If the Room be then darken'd, the Ends of the Threads on the Outside, will be all tipt with Fire. But those within are not, which shews that this Power acts only ab intra out∣wardly. p. 23.

Exp. 5. An Iron Rod being hung on Silken Strings, with one End about ¼ of an Inch from the Globe, will at the other End (which terminates in a conical Point) emit a Purple Flame diverging every Way. Hold your Finger within ¼ of an Inch, and the Fire will issue more largely. p. 24.

Exp. 6. Hold your Finger still nearer, and the Rays will be so condensed as to run to it in a Stream of Yellow Flame; which is also sensible to the Feeling, as a gentle Wind, and smells like the Fire of Phosphorus.

Exp. 7. If you put your Finger on the Rod, the Flame instantly disappears, the Fire all running off upon the Finger. But take it off, and the Flame appears again.

Exp. 8. Apply your Finger near a Tin Tube so suspended, and you may see the Fire, and both hear and feel the Snap. p. 25.

Exp. 14. Under an electrified Plate, put some Leaf-Gold or other light Substances on another Plate unelectrified: And it will be attracted and repell'd alternately, between the two Plates. For, each Time it touches the lower Plate, it discharges he Electric Fire, and so becomes again attract∣ble. p. 28.

Exp. 18. If to a Gun Barrel you adapt a small Tin Cup, and pour in Water; a Person holding his Finger perpendicular over the Water, within ¼ of an Inch of it's Surface, will find the Water rise in Form of a Cone to meet his Finger, and from the Top of it, a Stream of Fire will issue to the Finger and snap as usual p. 30.

Exp. 19. A dry Spunge is an Electric. But if it be dipt in Water, and then hung on the Barrel, put your Finger near it, and the Fire issues out, and the Drops which before fell very slowly, will now fall very fast. If the Room be darkened, they will appear as Drops of Fire. p. 3••.

Exp. 20. A Syphon hung on the Cup, drops very gently till it is electrified; but then the Wa∣ter runs in a Stream, which in the Dark is like a Stream of Fire.

Exp. 21. Open a Vein in a Person standing on the Rosin, and the Blood will fly out to a certain Distance. But let him be electrified, and it will spin out with a much greater Force, and to a far greater Distance.

Exp. 24. If Mercury be put for Water, the Electric Force is something greater, but in no Pro∣portion to it's Density.

Exp. 25. When the Mercury is saturated, the Electric Streams will issue thro' the Wire more co∣piously than from the Phial of Water, and will snap of themselves, which the Streams issuing from the Water never do.

Exp. 27. The electrified Phial will not retain the Fire very long: But if you hold it up in a dark Room, it wi••l be seen to go off from the Point of the Wire, in a small white Flame. p. 34.

Exp. 30. A Cup of Water held by an electri∣fied Person will emit Fire more forcibly than his Body. p. 35.

Exp. 32. A Person standing on the Ground, cannot easily kiss an electrified Person standing on the Rosin. p. 36.

Exp. 38. If a square Piece of Leaf Gold be placed between two Plates, about two Inches asun∣der, one of them electrified, the other not▪ at first it will be attracted, and repell'd alternately, till in a while it will lose its Motion, and remain sus∣pended between them. p. 39.

Exp. 42. If the Globe be exhausted of Air, and then turn'd, the electric Fire will act wholly within the Globe, where it will appear (in a dark Room) as a Reddish or Purple Flame, filling the whole Globe. But this, as the Air is re-admitted into it, will gradually disappear. In this Case, the electric Fire is confined within, by the elastic Air on the Outside. p. 4••.

An Ext••act from Mr. Watkins's Account of electrical Experiments.

When the Machine is to be used, the Globe should be wiped clean, with a clean, dry, warm Flannel, it's Pivots oil'd, and the Cushion and Phial warmed. In damp Weather, there should be a Fire in the Room. p 4.

Exp. 4. Let an unelectrify'd Plate, with scour∣ing Sand upon it, be held 5 or 6 Inches under an electrify'd Plate, and the Sand will be so attracted and repell'd, as to resemble a stormy Shower. p. 16.

Exp. 7. If a Glass Ball, of 4 or 5 Inches dia∣meter, be hung by a Wire to the Gun-barrel, and a Ball of ¾ of an Inch diameter, exceeding thin, placed on a smooth Plate, be brought near it, this will not only be attracted by the large Ball, but will perform continual Revolutions round it, ex∣actly as the Planets do round the Sun. p. 22.

Exp. 9. Hang a Loadstone on the Barrel, and a Key on the Armature of it: And if you bring

your Finger near the Key, it will snap and emit Fire. A plain Proof that the electric and magnetic Power no way hinder each other. p. 25.

Exp. 35. A Sparrow kill'd by the electric Shock, was found livid without, as if kill'd with a Flash of Lightning, and most of the Blood Vessels within were burst. Animals shock'd on the Head, if not kill'd, are commonly struck blind. p. 55.

Exp. 41. Ice held by an electrify'd Person, will fire warm Spirits of Wine. p. 61.

Exp. 43. Mr. Watson put an Ounce of Oil of Vitriol, an Ounce of Iron Filings▪ and four Ounces of Water, into a Flask. An Ebullition ensued. An electrify'd Person applied his Finger to the Mouth of the Flask. The Vapour took fire, and burnt out of the Neck a long Time. p. 63.

From an Experiment made by Mr. Watson, and others, it appear'd, that the electric Fire circulat∣ed, without Interruption, from the Surry Side of the Thames over Westminster Bridge, to the West∣minster Side, and thence thro' the River to the Surry Side again, which is upwards of 800 Yards. Spirits of Wine also were fired at the same Distance.

From this, and several other Experiments, it ap∣peared, that Distance, simply considered, did lit∣tle, if at all, impair the Force of the electric Shock.

They afterwards convey'd this Shock thro' a Circuit of four Miles, and sound the Motion of the electric Fire to be nearly, if not quite, instan∣taneous.