A Treatise on Electricity Wherein its various phænomena are accounted for, and the cause of the attraction and gravitation of solids, assigned. To which is added, a — Inside the Classic

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Its various _phænomena_ are accounted for, and the cause of the _attraction_ and _gravitation_ of solids, assigned.

A short account, how the electrical _effluvia_ act upon the animal frame, and in what disorders the same may probably be applied with success, and in what not.

By FRANCIS PENROSE Surgeon at _Bicester_.

They who are universally allowed the very greatest, and wisest of men, have been, and still are, intent upon the making of _observations_, and _experiments_: and surely that must be in order to some further end. These would be vain, and wholely useless, were not some reflections made, some conclusions drawn, some theory or hypothesis raised from them.

_Woodward_’s state of _physick_ and of _diseases_, p. 55.

Printed at the THEATRE for SACKVILLE PARKER, Bookseller at _Oxford_, and W. OWEN, at _Homer’s Head, Temple-Bar, London_. MD CC LII.

The many surprising effects of _electricity_, and the great cures performed by it, one would imagine, should awaken the attention of all philosophers and physicians; but as these cures have been effected by random experiments, every body has admired, but no body seems to have considered how, or by what means, they were performed. Whence

Notwithstanding all these surprising _phænomena_, from which many have entertained hopes of a great addition to the healing art; yet not one tolerable account has been given, how, or from what cause, these _phænomena_ proceeded; except what has been done by Mr. _Freke_, surgeon to _Bartholomew hospital_; whose admirable piece shews the great penetration of its worthy author, with whom I shall join in thinking “it may possibly be the beginning of much good.”

One would think, this silence, on so interesting a subject, _in this enlightened age_, can proceed from nothing but a prejudice in favour of wrong principles of philosophy: That this is certainly the taste of the present age, M. _Freke_ seems very well convinced; for, at the end of his pamphlet, he takes notice of a show-man, who, “having published some experiments in electricity, and hearing that Mr. _Freke_’s piece was publishing, own’d, he was much affrightened, because of the hard fate, as he said, of his booksellers; but, before he had read two pages, he likewise owned he had recovered his spirits, when he found Mr. _Freke_ pretended to think for himself, and did not let Sr. _Isaac Newton_ think for him.”

Now, if all persons would take the same freedom of thinking for themselves, as Mr. _Freke_ has done, I doubt not but we should soon be as much ashamed of mentioning the _attraction_ of _gravitation_, and the _attraction_ of _cohesion_ &c. as we now are of the _occult qualities_ of the ancient philosophers; and should perhaps, then agree with him, when, speaking of electricity, he says, that “it is a subject which can, with more nobleness and dignity, employ the mind of man, than any he can think of, relating to the sublunary part of the 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 his 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.” Therefore,

In the following essay, I shall endeavour to shew,

I. How, and from whence, this electrical fire and force are produced; in doing of which I shall make some observations, in order to shew that we may form a more exact idea of most of the great operations of that complete machine, the universe, from electrical experiments, than can be attained by any other means: I shall also produce some experiments which demonstrate, that the terraqueous globe has no _attraction_; nor a solid body, falling towards the earth, any _gravitation_; after which, I shall bring other experiments to prove what is the cause of _solidity_, and by what means bodies _gravitate_ towards the earth.

II. How this electrical fire and force act upon the animal frame, and in what disorders they are likely to be of benefit, and in what not.

I. We are certain, that this electrical fire is produced, either from the glass globe, or the air that surrounds it. As to the glass globe, Mr. _Freke_ has fully proved it cannot proceed from that; “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 glass globe, after ever so many times using, remains as fit for the same use, as at first.” From hence we assert, that this fire must proceed from the surrounding air being acted upon by the glass globe; and our inquiry must be, how, and by what means, fire is produced by the glass globe being made to act upon the air by which inquiry we shall find, that _air_, _light_, and _fire_ are of the _same substance_, or _essence_; only differently modified, and appointed for performing different actions: that air (by being divided or broke to pieces) produces light; and, if that action is still encreased, it produces fire. Now as the greatest friction or attrition are necessary to produce fire, so fire, when it is once produced, having received the greatest force, of consequence _acts_ with the greatest force; and light, with a less; so, wherever there is the greatest quantity of these small particles of air, (which we call by the name of fire) in proportion to what we call gross air, there the action must be the greatest; by which means the said fire or light will expand itself, ’till, by mixing with what we call gross air, it becomes of an uniformity with it. Now therefore, as experiments are the sure way either of proving or disproving any _hypothesis_; so, to illustrate this, I shall produce some experiments both from Mr. _Freke_, and other authors of unblemished credit, which prove that air is convertible into light and fire, and also that light and fire are convertible back again into air; and likewise, as some parts of the air are present in all places and things, that therefore, whenever a violent action either of solids or fluids is brought on, there light, fire, or heat, are produced.

To prove this, Mr. _Freke_ has brought, two very simple, common, but good experiments--First, if you slide a wax thread, or small rope, through your fingers, it will burn them; so likewise fire is produced, by rubbing two hard bodies together, or two sticks; or, as is very often the case, a cart or coach wheel will take fire, for want of grease.

Another no small proof of this, is what Mr. _Freke_ has mentioned, viz. that in the year 1703, in the night of the great hurricane and high wind, in the strongest part of the tempest, great quantities of fire were seen passing swiftly over the hills in the neighbourhood of _Warham_ in _Dorsetshire_. The cause of which fire seems very easily accounted for, according to the above theory, which might otherwise perhaps, elude the searches of our greatest philosophers: for in this phænomenon it is plain, that the attrition of the particles of the air was so great by the motion of the wind, as to produce fire or light. Mr. _Freke_ has some other observations, which much strengthen the above theory, viz. that in tempestuous weather, at sea, great flakes of fire are frequently seen passing, not only in the air, but on the water. The like is also observed, in the night time, when the surface of the water is disturbed with the feathering of oars, or by a vessel or boat passing swiftly through it. This light or fire _in storms_ is no new observation; for Mr. _Boyle_ says, it is common in storms for the fire called _Helena_, _Castor_, and _Pollux_, to hover about the masts of ships. And, indeed,

To shew that fire or heat are produced in any place, or thing, where there is a sufficient motion, seems not to be very difficult; for water is the opposite to fire; and yet, by mixing water and spirit of wine _suddenly_ together, a heat ensues; and this will happen if they have been separated ever so often; but this heat vanishes again after they are mixed, or as soon as the _motion_ of their parts ceases. The like will happen by mixing salt of tartar and water. This phænomenon seems to proceed from the disposition and texture of the salt; whose pores are made of such a proper size, that, on receiving the water by the pressure of the atmosphere into them, the texture of the salt may be thereby broken, and its parts put _into motion_; which _motion_ causes an _attrition_ of the air, and so produces a sensible heat.

_Boerhaave_ has another observation, which seems to prove to a demonstration, that fire or heat is caused by an _attrition_ of the air; which observation I shall give in his own words. “A cannon ball, shot in the winter time, will fly 600 feet in a minute through the cold air, which makes a greater resistance than any wind, the most rapid of which only moves 22-1/2 feet; hence it appears how much _friction_ the ball must have undergone in its passage, which by the way did not proceed in a right line, but by its whirling motion continually describes a cycloid with every point of its body. When it falls, it is found quite hot; notwithstanding in its whole passage, it had continually met with cold air. This heat could not have arisen from the flaming gunpowder, whereby it was exploded, since it only remained in that flame, an incredible small space of time, in which it is by no means credible so solid a body should have acquired such a heat; which is much more naturally accounted for from the great attrition of the ball, driven with such a velocity through the air, and repelled by a wind, which is above 27 times swifter than the strongest wind hitherto observed.” _Boerhaave_’s Chym. by _Shaw_, Vol. 1. pag. 244.

I shall mention one more experiment from Mr. _Boyle_, which proves that _air_ is not only convertible into _light_; but that it may afterwards be forced through glass, and thereby the same _vacuum_ be made that is by an air pump. “Liquid phosphorus being put into a vial, when it was disposed to shine in the dark, the cavity of the vial above the liquor seemed to be full of whitish fumes, though at other times transparent. The vial, when close stopped, was not luminous in the dark, but the light or flame appeared as soon as it was exposed to the air, and the vial was unstopped; and that the occasion and propagation of this flame depended on the contact of the air, appeared, since agitation would not kindle it, but when the bottle was unstopped, the kindled flame would gradually be propagated downwards; the flame always appeared most vivid the nearer the air, and when it was extinguished, it first disappeared in the bottom, and then expired at the top. When the Vial was unstopped for some time, when it was stopped again, the air that had leisurely insinuated itself would cherish the flame for an hour or two. It was observable, that when the air had been long pent up with this shining liquor, its resistance would be so weakened, that when the vial was unstopped, the external air would presently rush in with violence, from whence appears the interest of the air in propagating the shining of this liquor. The agitation before the vial was unstopped would not kindle the light; yet when it was opened, it would be increased by it, and even when it was in its dull state, if I poured a little of it upon my hand, and rubbed it with my finger, it would presently become vivid, and emit store of luminous rays, as well as fumes very offensive to the nostrils; and when I ceased to rub, and the luminous quality was lost, it would be renewed again by a repeated attrition; but in a little time its lucid virtue would decay,” _Boulton_’s Epitome of _Boyle_’s works, vol. 2. pag. 246. From these experiments it may be observed, that this liquid phosphorus could not be made to emit light, without a communication with the air, not even by the utmost agitation; though when it had a free communication with the air, a small agitation greatly increased the quantity and strength of the light; that, whenever the air was admitted to join it, a violent intestine motion came on, by which motion or attrition, light was not only produced, but also a great deal of the liquid was carried off by it; which might be perceived either by the sight, or smell. And when the vial had been long without a cork, by which means it was filled to the utmost with air, the light would continue a considerable time after the vial was stopped. We likewise find, that, after the vial has been stopped some time, and the liquor has acted upon the air as much as it possibly can, there is not only a less quantity of gross air than there was when the vial was first stopped, but that there is the same _vacuum_ as is made by the air pump; for as soon as ever it is unstopped, the air presseth in with violence, the fluid above the phosphorus (within the vial) being of a more subtle nature than the air without.

This experiment seems sufficiently to prove, that air and light are of the same essence or substance; for we are certain that gross air entered the vial, and, when it was first stopped, the quantity of gross air was of an uniformity with the air without the vial; but at its being opened, we are assured, there was a less quantity than when it was first stopped; for the air without presseth in with the same violence it does into the exhausted receiver of an air-pump; by which we may be assured, that some parts of the air have passed the vial in form of _light_; and, as the pores of the glass are not big enough to admit gross air to return, the consequence must be, that there is a less quantity of gross air in the vial at the opening, than there was, when it was first stopped.

Fire and light are easily proved to be dispersed through the whole air, from the immediate action of _speculums_; and that air itself is of the same substance with fire seems very plain; for as fire cannot subsist without air, (and in proportion to the quantity of air forced into the fire, in such proportion will be the force of the fire;) so, neither can fire act but on the outside of bodies next the air; for even the most inflammable bodies can only catch fire on their outermost surface contiguous to the air; and fire in action, if immerged in a body of the most inflammable matter, so as to leave no lighted part above such surface in the air, will be so far from kindling the inflammable body, that itself will be extinguished. Thus “if a flaming brimstone match be plunged into the highest rectified spirit of wine, the spirit of wine will extinguish it as intirely, as if dipped in cold water; it will also extinguish a live burning sparkling coal; but in the former experiment, if the least bit of the burning match remains above the spirit of wine, it will then catch fire, and the flame will presently spread over the whole surface.” This is an experiment of the great _Boerhaave_, in the first vol. of his chymistry, by _Shaw_, pag. 316.

All these experiments, I think, prove to a certainty, that air is convertible into light. I shall now bring one experiment, from _Boerhaave_, Vol. 1. p. 998. which proves, that fire or light may be changed into air.

“If a spherical glass vial be kept in a glass-house furnace, till ready to melt, and then be hermetically sealed in that heat, and suffered to cool; if now, it be held inverted, under cold water, and the end of the neck be carefully broken off, the water will be violently forced into it, and fill the glass, but so as to leave a bubble of true elastic air at the bottom.”

The above experiments prove, that, whenever air is sufficiently divided or broken to pieces, light is produced; so that the light or heat in electricity, is no other than, we find, may be produced several other ways. For the air being violently rubbed or ground to pieces between your hand and the glass globe, whirled briskly about, the air between your hand and the globe is ground so small as to be in the form of _light_, which is expanded or sent off from the glass globe in the same manner as _light_ from a candle, or other luminous body; which emission is continually supplied by the common air pressing in between the rays of _light_, emitted from the glass ball. That this is the method, by which it acts, seems very clear: for you may not only hear the hissing noise of the air pressing towards the globe, but also plainly feel the air with your hand, near the globe or tube.

The chief reason (and what has been our great misfortune) that we have not been able to discover the cause of electricity, seems to be the leaving that philosophy, which has been _revealed_ to us, and putting in its stead _theories_ of _our own invention_. For, if we had considered (from the _revealed_ account that is given us of the formation of light) the _method_ of its _first_ production, we should not be at such a loss to account for that light in electricity, as we hitherto seem to have been; for we are _there_ told, that the _heavens_, or airs, were created in a state of _darkness_, or inactivity; and that the first thing God did, was to cause a _motion_, or _wind_ amongst the airs; which _motion_ was to _continue_, and _encrease_, till it produced _light_; and, after this _light_ was produced, God called it _Day_, or as it is expressed in the original, _tumultuousness_; it being produced from the impetuous or violent motion of the airs: and the _darkness_ he called _night_, or, as it is likewise expressed, the time when this _languishes_ or _decays_; for the _congealing_ or _thickning_ of the air, by which _darkness_ is produced, is in proportion as the _force_ of the _light_ abates.

By all which, I think, we may be assured, that the _light_, and all the _phænomena_ produced in electricity, are caused by a violent _friction_ or _grinding_ of the grains of air between the glass globe and the hand.