Experiments and observations tending to illustrate the nature and properties of electricity : in one letter to Martin Folkes, Esq, President, and two to the Royal Society

EXPERIMENTS AND OBSERVATIONS Tending to illustrate the NATURE AND PROPERTIES OF ELECTRICITY. InoneLETTERtoM?r*« Fo/^^’j,Efqj Prefident, and Two to the Royal Society. By WILLIAM WAI' SON, $ L0NDON: Printed by Jacob Ilive, for the AUTHOR MDCC XLV. TO Martin Folkes, Efq; P. R. S, SIR, I rg^HE. Society having heard from fome of their Correfpondents in Germany^ that what they call aVegetable Quinteffcnce, had been fired by Electricity, Itake this Opportunity to acquaint you, that on Friday Evening laft I fucceeded, after having been difappointed in many Attempts, in fetting Spirits of Wine on Fire by that Power. The preceding Part of the Week A2had had been remarkably warm, and the Air very dry, than which nothing is more neceflary towards the Succefs of Eledtrical Trials ;to thefe Imay add, that the Wind was then Eafterly and inclining to freezing. Ithat Evening ufed aglafs Sphere as well as aTube ; but Ialways find myfelf capable of fending forth much more Fire from the Tube than from the Sphere, probably from not being fufficiently ufed to the laft. Ihad before obferv’dj that although *non Eleftric Bodies made eledrical, loofe almoft all that Eledricity by, coming either within .*Icall EleSlrics per fe or originally EieSricu thofe Bodies, -in which an attrailive Power towards light Subftances is eafily excited by Fridtion ;fuch as Glafs, Amber, Sulphur, Sealing-wax, and moft dry Parts of Animals, as Silk) •Hair and fuch like. Icall non EleSirics or Conductors of EleCtricity, thofe Bodies, in which the above Property is not at all or very (lightly perceptible-, fuch as Wodd, A- nimals living or dead. Metals and vegetable Sub- Itances. See Gray^ Du E'ay, Defaguliersy IVhtler , in the Philofophical TranfaClions. C5] in or near the Contad: of non Electrics not made eledtrical ;it happens otherwife with Regard to EleSlrics per fey when excited by rubbing, patting, ^Cy becaufe from the rubbed Tube Ican fbmetimes procure five or fix Flafhes from different Parts, as though the Tube of two Foot long, inftead of being one continued Cylinder, confifted of five or fix feparate Segments of Cylinders, each of which gave out.its Eledricity at adifferent Explofion. 'The Knowledge of this Theorem is of the utmoft Confequence towards the Succefs of eledlrical Experiments ; inafmuch as you muff endeavour by all poffible Means to collea the Whole of this Fire at the fame Time. Profeffor Hollman feems to have endeavour’d at this and fuccceded, by having atin Tube, in one End of which he put a -great many Threads, whofe Extremities touch dthe Sphere when in Moti- on, and each Thread colleded aQuantity of eledlrical Fire, the Whole of which center’d in the tin Tube, and went off at the other Extremity. Another Thing to be obferv’d, is to endeavour to make the Flafhes follow each other fo faff, as that aSecond may be vilible before the Firft is extinguifh’d. When you tranfmit the electrical Fire along aSword or other Inftrument, whofe Point is fharp, it often appears as aNumber of diffeminated Sparks, like wet Gunpowder or Wildfire ;but if the Inftrument has no Point, you generally perceive a pure bright Flame, like what is vulgarly call’d the Blew-ball ^ which gives the Appearance of Stars to fired Rockets. The following is the Method I made ufe of and was happy enough to fucceed in. Ifufpended aPoker in filk Lines ;at the Handle of which I hung feveral little Bundles of white Thread, crceire at is f] ijcligire to fi/K rtliod 1 oughts oker in 'hicb i whits ‘hrcd C7] Thread,' the Extremities' of which were about aFoot at right Angles from the Poker. Among thcfe Threads, which were all attraded by the rubbed Tube, Iexcited the greateft eledirical Fire Iwas capable of, whilft an Afliftant near the End of the Poker held in his Hand aSpoon, in which were the warm Spirits ;thus the Thread communicated the Electricity to the Poker, and the Spirit was iired at the other End. It muft be obferv din this Experiment, that the Spoon with the Spirit muft not touch ^ the Poker ;if it does, the E- ledricity without any flafhing is communicated to the Spoon, and to the. Aftiftan^t in whole Hand it is held and lo is loft mthe Floor. By thele Means, Ifired feveral Times not only the stherial Liquor or Phlogifton of Frobenius and redified I^ ^ ^^I even common proof Spirit. Thefe Experiments, as I ( Ibefore obferv’d, were made laft Frt^ day Night, the Air being perfeftly dry. Sunday proved wet and Monday pretty warm, fo that the Air was full of Vapour; Wind South Weft and cloudy. Under thefe Difadvantages, on Monday Night Iattempted again my Experiments; they fucceeded, but with infinitely more Labour than the precceding, becaufe of the Unfitnefs of the Evening for fuch Trials. Your Candour will not permit you to think my Minutenefs trivial, with Regard to the Circumftances of the Weather, who know, how many Things muft concur to make thefe Experiments fucceed. Ifhall wait with Impatience for aproper Opportunity to have thefe Experiments repeated in your Prefcnce, and am with the utmoft Relped, Sh'' your moft obedienty Alderf gate- 5 treet^ March!'] 1745* humble Servanty W. Watson. f Royal Society. .Gentlemen, ILA'TELYacqudnted you, that Ihad been able to. fire Spirit of Wine, Phlogiflon of Frobenius^ and common proof Spirit, by the Power of Eledricity. Since which (till Yef-> terday) we have had but one very dry fine Day ;viz. Monday^ April 15 , Wind E. N. E;when about four o’ Clock in the Afternoon Igot my Apparatus ready, and fired the Spirit of Wine four Times from the Poker as before, three Times from the Finger of aPerfon electrified ftanding, upon 1 [><s ] T O THE Royal Society. Gentlemen, rNfome Papers Ilately did myfelf athe Honour to lay before you, I acquainted you of fome Experiments in Electricity ;particularly Itook notice of having been able to lire Spirit of Wine by what Icall’d the repullive Power thereof, which Ihave' not heard had been thought off by any of thofe German Gentlemen, to whom the World is obliged for many furprizing Difcoveries in this Part of natural Philofophy, How 1 C17 ] How far ftridly fpeaking the Spirit in this Operation may be faid to be fired by the repulfive Power of Electricity, or how far that Power, which repels light Subftances when fully impregnated with Eledricity, fires the Spirit, may probably be the Subjed of afuture Inquiry ;but as Iam unwilling to introduce more Terms into any Demonftration than what are abfolutely neceffary for the more ready Conception thereof, and as inflammable Subftances may be fired by Electricity two different Ways, let the fol - lowing Definitions at prefent fuffice of each of thefe Methods. But firft give me Leave to premife, that no inflammable Subftances will take fire, when brought into or near the Contad of EleSirics perfe excited to Eledricity ;this Effed mui\i be produced by non eledrical Subftances impregnated with Eledricity re- ^ceived »^ [x8] ceived from the exciting EleSfrics per fe. But to retun, i/, ISUPPOSE that inflammable Subftances are fired by the attradive Power of Electricity, when this Effect arifes from their being brought near excited non EleCtrics. 2dly^That inflammable Subftances are fired by the repulfive Power of Electricity ;when it happens, that the inflammable Subftances being firft eleCtrified themfelves, are fired hy being brought near non EleCtrics not excited. •This Matter will be better illuftrated by an Example; fuppofe that either aMan ftanding upon aCake of Wax, or aSword fufpended in filk Lines are eleCtrified, and the Spirit being brought near them, is fired, this is faid to be perform’d by the attractive Power of Electricity. But if the Man electrified as before holds aSpoon in his Hand containing the Spirit, or the [IP ] the fame Spoon and Spirit are placed upon the Sword and aPerfon not eled:rified applies his Finger near the Spoon, and the Spirit is fired from the Flame arifing from the Spoon and Spirit upon fuch Application ;this I call being fired by the repulfive Power, Of the two mention’d Kinds Igenerally find the repulfive Power ftrongeft. Since my laft Communication, the Spirit has been fired both by the attractive and repulfive Power through four Perfons ftanding upon eleCtrical Cakes 5each communicating with the other either by the Means of awalking Cane, aSword, or any other non electric Subfiance. It has likewife been fired from the Handle of aSword held in the Hand of athird Perlon. IHAVE not only fired Frobenius\ Phlogifion, rectified Spirit and common proof Spirit, but alfo fal volatile Oleofum, Spirit of Lavender, dulcified ^2Spirit Spirit of Nitre, Peony Water, Daffy\ Elixir, Helvetius\ Stiptick, and fome other Mixtures where the Spirit has been very conhderably diluted; likewife diftilled vegetable Oils, fuch as that of Turpentine, Lemon, Orange Peels and Juniper, and even thofe of them, which are fpecifically heavier than Water, as Oil of Saffafras; alfo rehnous Subftances, fuch asBalfam Ca- I pivi and Turpentine; all which fend j forth when warmed an inflammable Vapour. But expreffed vegetable Oils, as thole of Olives, Linfeed and Almonds, as well as Tallow, all whofe Vapours are uninflammable, Ihave not been able yet to fire ;but thefe indeed will not fire on the Application of lighted Paper. Befides, if thefe lall would fire with lighted Paper, unlefs their Vapours were inflammable, Ican fcarce conceive they would J fire by Eledlricity; becaufe in firing Spirits, Ialways perceive that the ledricity JfSpnii uluted;! lion, Os; tixe *!b) iiiBdial, 1whklir illiiaisa cgetaiileG, ced and.I' allsis ible, lis but ts, ht&i Pfi [jfV fId ^ .p C] Eledlricity fhaps before it comes in Contad: with their Surfaces, and therefore only fires their inflammable Vapours. As an excited non Electric emits almofl: all its Fire, if once touch’d by anon Eledlric not excited. Iwas defirous of being fatisfy’d, whether or no the Fire emitted would not be greater or lels in proportion to the Volume of the electrified Body. In order to this Iprocur’d an Iron Bar about five Feet long and near 1.70 Pounds in Weight ;this Ieledrified lying on Cakes of Wax and Rofin, but obferv’d the Flafhes arifing therefrom not more violent than thofe from acommon Poker. In making this Experiment, being willing to try the repulfive Force, it once happen’d that whilfl: the Bar was at one End eledrifying, a.Spoon lay upon the other, and upon an Afliftant’s pouring fome warm Spirit into the Spoon, the electrical [22 ]f • tricai FlaOi from the Spoon fnapped and fired the firft Drop of the Spirit, which unexpedledly fired not only the whole Jett as it was pouring, but kindled likewife the whole Quantity In the Pot, in which Iufually have it warm’d. IFIND that in firing inflammable Subftances from the Finger of aMan {landing upon Wax, that cceteris paribus the Succcfs is more conftant, if the Man inftead of holding the Thread (the Ufe of which Icommunicated in aformer Paper) in his Hand, the Thread is fufpended at the End of an Iron Rod held in one Hand, and he touches the Sj irit with one of the Fingers of the other. If aMan ftanding upon the electrical Cake with aDifh or deep Plate of Water in one Hand, and the Iron Rod with the Thread in the other, is made eledrical ;and aPerfon not eledtrified touches any Part either of the Plate Plate or Water, the Flafhes of Fire come out plentifully, and wherev^er you bring your Finger very near, the Water rifes up in alittle Cone, from the Point of which the Fire is produced, and your Finger though not in actual Contact is made wet. The fame Experiment fucceeds through three or more People. In firing infiammable Subftances, the Perfon who holds the Spoon in his Hand to receive the eledrical Flafiies, when the Finger of the ele^rified Perfon is brought near thereto, not only feels atingling in his Hand, but even aflight Pain up to his Elbow. This is nioft perceptibly in dry Weather, when the Eledlricity is very powerful. ^ ^There is aconfiderable Difficultv mfinng Ekaria perfe, fnch as Turpenbne, and Balfam Capivi by the repulfive Power of EJedricity/ becaufe •n tbs Cafe thefe Subftances will permit [^4 3 permit the Eledricity to pafs through them, therefore when you would have this Experiment fucceed, the Finger of the Perfon who is to fire them is to be applied as near to the Edge as poffible of thefe Subftances when warm’d in, aSpoon, that the Flaflies from the Spoon (for thefe Subftances will emit none) may fnap, where they are fpread the thinneft and then fire their Effluvia. This Experiment, as well as feveral others, ferves to confute that Opinion which has prevail’d with many, that the Eledricity floats only upon the Surfaces of Bodies. If an eledfical Cake is dipp’d in Water, it is thereby made aCondudor of Eledricity, the Water hanging about it tranfmitting the eledrical Effluvia in fuch amanner, that aPerfon ftanding thereon can by no means be eledrified enough to attrad the leaf Gold at the fmalleft Diftance ;though the Perfon ftanding upon the fame Cake [^5 ] Cake when dry, attradled aPiece of fine Thread hanging at the Diftance of two Feet from his Finger. We muft here obferve that the Cake being of an unctuous Subftance, the Water will no where lie uniformly thereon, but adhere in feparate Moleculae ;fo that in. this Inftance the Electricity jumps from one Particle of Water to another till the Whole is difiipated. From the Appearance of the Threads among/!: which Irub the Tube, Ican frequently, judge though, the Spirit may be many Feet diftant from them, whether or no, it will fire, becaufe when the Perfons /landing upon the Wax are made eleClrical enough to fire the Spirit, the Threads repel each other at their lower Parts where they are not confin d^ to aconfiderable Di/lance, and this Di/lance is in Proportion as the Threads are made electncal. [] illuftrate this Matter further, Ihave been able when the Weather has been very dry, vvith once rubbing my Hand down this Blue Tube and applying it to the End of an Iron Rod fix Feet long, to throw off feveral Pieces of Leaf Silver lying upon aCard at the other. End of this Rod, whereas Inever have been able to throw it off by any Means in very wet Weather. Befides Iam of Opinion, that after the Electrical Fire is gone from the Tube, the Tube has no Share in the conduding of it ;my Sentiments on that Head Ilaid before you in aformer Paper :For if the Silk Lines are wetted they diffufe all the EleCtricity, and the fame EffeCts happen when the Air is wet, be your Glafs of what Colour it will. It may not be improper here to obfcrve, that Zaffer, which is ufed by the Glafs-makers and Enamellers, is made of Cobalt or Mundick calcin’d after the fubliming the Flowers. i i I 1 I I I [33 ] Floors. This being reduced to avery fine Powder, and mixt with twice or thrice its own Weight of finely powdered FHnts, is moiften dwith Water and put up in Barrels, in which it foon runs into ahard Mafs and is call’d Zaffer. ADRY Sponge hanging by aPackthread at the End of an eledrified Sword, or from the Hand of an electrified Man, gives no Signs of being made EJedrical ;if it is well leak’d in Water, wherever it is touched you both fee and feel the Eleftrical Sparks. Not only fo, but if it is fo full of Water, that it falls from the Sponge, thofe Drops in adark Room, receiv’d upon your Hand, not only flafli and fnap, but you perceive apricking Pain. If you hold your Hand or any non Electrical Subftances very near, the Water which had ceafed dropping when the Sponge was not electrified, drops again upon its being 3 electrified, and the Drops fall in Proportion to the receiv’d EleClricity, as though the Sponge were gentlv fijueez’d between your Fingers. I was defirous to know if Iwas able to electrify aDrop of cold Water, dropping from the Sponge, enough to fire the Spirit ;but after many unfuccefsfui Trials, Iwas forced to defift, becaufe the cold Water dropping from the Sponge not only cool’d the Spirit too much, but alfo render’d it too weak ;likewife every Drop carried ,with it, great Part of the Electricity from the Sponge. Ithen confider’d in what Manner, Icould give aTenacity to the Water, fufficient to make the Drops hang aconfiderable Time, and this Ibrought about by making aMucilage of the Seeds of Fleawort. Awet Sponge then, fqueez’d hard and fill’d with this cold Mucilage was held in the Hand of an electrified Man, when the Drops forced ) j I $ V C35 ] forced out by the Eledricity, afllfled by the Tenacity of the Liquor, hung fome Inches frcm the Sponge, and by aDrop of this Ifir’d not only the Spirit of Wine, but likewife the inflammable Air before mentioned both with and without the Explofion. What an extraordinary Effect is this 1 That aDrop of cold Water (for the Seeds contribute nothing, but add .Confiftence to the Water) fhould be the Medium of Fire and Flame. Camphor is avegetable Refin and of Confequenee an Eledric per fe» This Subflance notwithflanding its great Inflammability, will not take fire from the Finger of aMan or any other Body eledrified, though made very warm and the Vapours arife therefrom in great Abundance. Becaufe neither Elcdric’s perfe excited, or e-' ledrified Bodies, exert their Force upon Eledric’s perfey though not excited. If you break Camphor fhiall E2and [36 ] and warm it in aSpoon, it is not melted by Heat like other Refins, but if ^that Heat were continued it would all prove Volatile. To Camphor thus warm’d, the Finger of an eledrified Man, aSword or fuch like, 'will in Snapping exert its Force upon the Spoon^ and the Circumambient Vapour of tlie Camphor will be fired thereby, and light up the whole Quantity expofed. The fame Experiment fucceeds by the repulfive Power of Electricity. APoker thoroughly ignited put into Spirit of Wine, or into the diflilled Oil of Vegetables, produces no Flame in either ;it indeed occafions the Vapours to arife from the Oil in great Abundance. 'But if you eleCtrify this heated Poker, the electrical Flafhes prefently kindle Flame in either. The Experiment is the fame witli Camphor. Thefe Experiments as well as the following fufficiently tvince I [37 ]9 vince that the eledrical Fire is truly Flame, an4 that extreamly fubtil. IHAVE made Several Trials in Order to fire Gunpowder alone, which I tried both warm and cold, whole and powder’d, but never could make it fiicceed ;and this ariles in part from its Vapours not being inflammable, and in part from its not being capable of being fir’d by Flame, unlefs the Sulphur in the Compofition is nearly in the State pf Accenfion. This we fee by putting Gunpowder into a Spoon with redified Spirit, .which when lighted, will not fire the Powder, till by the Heat of the Spoon from the burning Spirit, the Sulphur is almoft: melted. Likewife, if you hold Gunpowder ground very fine in aSpoon over alighted Candle, or any other Flame, as loon as the Spoon is hot enough to melt the Sulphur, you fee ablue Flame and inftantly the Fo^vder flalhes olF. The lame Eflbas t [38 ] EfFefts are obferv’d in the Pulvls fuL minanSj compos’d of Nitre, Sulphur, and fixed Alkaline Salt. Befides when the Gunpowder is very dry and grouiKl very fine, it (as you pleafe to make the Experiment) is either attraded, or repell’d ;fo that in the firft Cafe, the End of your Finger when eledrilied fiiall be cover’d over with the Powder, though held at fome Diftance ;and in the other, if you eledrify the Powder, it will fly off at the Approach of any non eledrified Subftance and fometimes even without it. But Ican at Pleafure fire. Gunpowder and even difeharge aMuiket by the Power of Eledricity, when the Gunpowderhas been ground with alittle Camphor or with afew Drops of fome inflammable chemical Oil ;this Oil fomewhat moiftens the Powder and prevents its flying away ;the Gunpowder then being warm’d in. aSpoon, the eledrical Flafhes fire the inflammable Vapour, «•I » C39 ] which fires the Cunpowder: But the Time between the Vapour firing the Powder is fo fhort, that frequently they appear as the fame and not fuccefiive Operations, wherein the Gunpowder itfelf feems fired by the E- ledricity ;and indeed the firft Time this Experiment fucceeded, the Flafti was lb hidden and unexpected, that the .Hand of my Afliftant, who touch’d the Spoon with his Fing^, was confiderably Icorch’d. So that there feems afourth Ingredient neccffary to make Gunpowder readily take Fire by Flame, and that fuch aone, as will heighten the Inflammability of the Sulphur. In common Cafes the lighted Match or the little Portion of red hot Glafs, 'which falls among the Powder and is the Refult of the Collifion from the Flint and Steel, fires -^ the Charcoal and Siilphur, and theft the Nitre. But if to theft three Ingredients you add afourth, viz. aVegetable [4° J getable chemical Oil, and gently Warm this Mixture, the Oil by the Warmth mixes intimately with the Sulphur, lowers its Conliftence, and makes it readily take fire by Flame. In thefe Operations notwithfianding Ialways made ufe of the fineft fcented Oils of Orange Peel, Lemons and fuch like, yet upon the leaft warming the Mixture, the rank Smell of Balfam (/. e. the ready Solution) of Sulphur was very obvious. Read before the R. S. 06i. 24. 1745. AContinuation of the above. Read, Feb. 6. 1745* ASWater is anon Elei^tric and of Confequence aConductor of Eledlricity, Ihad Reafon to believe that Ice was endowed with the fame Properties. Upon making the Experiment, %r4- j penment Ifound my Conjectures not without Foundation, for upon electrifying aPiece of Ice, wherever the Ice was touched by anon EleCtric, it flaihed and fnapped. APiece of Ice alfo held in the Hand of an electrified Man as the beforementioned Procefies, fired warm Spirit, chemical vegetable Oils, Camphor, and Gunpowder prepared as before. But here great Care muft be taken that by the Warmth of the Hand, or of the Air in the Room, the Ice does not melt ;if fo, every Drop of Water therefrom confiderably diminifhes the received EleCtricity, In Order to obviate this, Icauled my Afliftant, while he was electrifying, to be continually whiping the Ice dry upon aNapkin hung to the Buttons ofhis Coat, and this being eleCtrified as well as the Ice, prevented any Lofs of the Force of the Electricity, The Experiment will fucceed likewife, if inftead of the Ice, you eleCtrify the Spi- Frit, C48] heceflary that they are originally Ele(i* tries. But the Cafe is widely different with Regard to non Electrics ;wherein the Direction, given to the E- ledricity by the excited originally E- ledric, is alter’d as foon as it touches the Surface of anon Ele6lric, and is propagated with aDegree of Swiftnefs fcarcely to be meafured in all poffible Directions to impregnate the whole non Eledric Mafs in Contad with it or nearly fo, however different ,in itfelf, and which muff of neceflity be terminated by an originally Eledric, before the Eledricity exerts 'the leaft Attradion, and then this Powder is obferved firft at that Part of , the non Eledric the moft remote for the originally Eledric. Thus fof Example, by an excited Tube held over it, Leaf Gold will be attraded through Glafs, Cloth, &‘c, held horizontally in the Hand of aMan ftanding upon the Floor and this Attradion [49 ] tradion is exerted to aconfiderable Diftance. On the contrary, the rubbed Tube will not attradl Leaf Gold or other light Bodies however near through Silver, Tin, the thinneft Board, Paper, or any other non Electric, held in the Manner before mentioned. But if you rub the Paper over with Wax melted, and by that Means introduce the originally Eledric therein, you obferve the Eledricity ads in right -Lines and attrads powerfully. And here Imuft beg leave to remind you, not only of the former Corollary, but of fome of the former Experiments alfo ;by which it appears, that although to make anon Eledric exert any Power, we muft excite the whole Mafs thereof, yet wc can excite what Part and what only of an originally Eledric wepleafe. Thus we obferve, that Leaf Gold and the Seed of Cotton-grafs, which grows upon Boggs and is avery proper Subjed for thefe In- Gquiries, C50 3 I quiries, are attra6led under aGlafs Jar turned Bottom upwards, upon which are placed Books and feveral other non Ele^rics, and that the Motions of the light Bodies underneath correlpond with the Motions of the Glafs Tube held over them, the Eledricity .feeming inftantaneoufly to pafs through the Books and the Glafs. But this does not happen, till the Eledricity has fully impregnated the non Eledrics which lie upon the Glafs, which received E- ledricity is flopped by the Glafs, and then thefe non Eledrics, dart their Power diredly through the upper Part of the Glafs after the Manner of originally Eledrics. But if the thinneft non Eledric, evert the fineft Paper, as Ibefore mentioned, is held in the Hand of aMan at the fmalleft Didance over the Leaf Gold and the Eledricity is not flopped, not the leall Power will be exerted and the Gold will lie dill. Imud here remark like- [S' ] likewife, that this Law of Eledricity is fo conftant and regular, that Ihave not found one Deviation from it ;fo that even the Quickfilver, fpread thin as it ufually is at the Back of aPlate of aLooking-glafs, will prevent the palling through of the eledrical Attraction, unlefs flopped by an originally Electric. This Penetration of the electrical Power through originally Electrics is much greater than has hitherto been imagined, and has caufed the Want of Succefs to great Numbers of Experiments. Ihave been at hb fmall Pains to determine, how far this Power can penetrate through a dry originally EleCtric ;and have found by repeated Trials, that either in a Cake of Wax alone or of Wax arid Refin mixed, when the Electricity is very powerful, it has pafled, Ifay, in flraight Lines through thefe Cakes of the Thicknefs of 2Inches and foJ'hut A. ^could make it aCt through one G2of ,,1 of 2Inches for iri this it was perfedly flopped. So that the Cakes commonly made ufe of to flop the Electricity, by being too thin fufe a conhderable Quantity of the eledrical Power to pervade them, and -be loft in the Floor. Imake no Doubt, if -the electrical Power could be more increafed, it would penetrate much further through thefe originally Electric Bodies. Proposition III. ) i• i tElectricity in common with ILight likewife, when its Forces are collected and aproper Direction given thereto upon aproper ObjeCt, produces Fire and Flame. Corollary. • ' 1' HEFire of EleClricity (as Ihave before obferved) is extremely delicate and \ S3 J and fets on Fire, as far as Ihave yet experienced, only inflammable Valours. Nor is this Flame at all !leightned by being fuperinduced upon an Iron Rod, red hot with coarfer culinary Fire as in apreceeding Experiment, nor diminifhed by being dire<Sfced upon cold Water. However Iwas defirous of knowing, if this Flame would be affected by aftill greater Degree of Cold ;and in Order to determine this, Imade an artificial Cold, by which the Mercury, in avery nice Thermometer adjufted to Fahrenheit^ Scale, was deprefled in about Minutes from 15Degrees above the freezing Point to 3oDegrees below it, that is, the Mercury fell 45 Degrees. From this cold Mixture when eledrified, the Flafhes were as powerful and 'the Stroke as fmart as from the red hot Iron. Icould have made the Cold more intenle, but the above was fufficient for my Purpole. This Experiment [54 ] jnent feems to indicate, that the Fire of Eleflricity is affedled neither by the Prefence or Abfence of other Fire. For as red hot Iron, by Sir Ifaac, Nemtons Scale of Heat, is fixed at 192 Degrees, and as the Ratio between Sir Ifaacs Degrees and Fahrenheit\ is as 34 to 180, it .necefiarily follows, that the Difference of Heat between A the hot Iron and the cold Mixture is 1040 Degrees, and neverthelefs this vaft Difference makes no Alteration in the Appearance, of the clerical ,Flame. IMAY perhaps be thought too mb nute in feme of the before mentioned Particulars ;but in Inquiries abftrufe as thefe are, where we hav^ fo little ^ friori to direct: us, the greateft Attend tion muft be had to every Circum-r ftance, if we are truly defirous of in^ veftigating the Laws of this flirprizing Power. For as has been faid upon ar nother Occaiion by my ever honoured 1 I \ C55 ] Friend .Martin Folkes, Efq; ouf moft worthy Prefident, “that Elec- “tricity feems to furnifli an inexhau*^ “ftible Fund for Inquiry, and fure ‘‘ Phoenomena fo various and fo wonderful can arife only from Caufes ve- “ry general and extenfive, and fuch as “muft have been defigned by the Al- “mighty Author of Nature, for the “Production ofvery great EIFeds, and “fuch as are of great Moment to the «Syftem of the Univerfe.” IFthele Obfervations receive the Countenance of this learned Society, Ifliall think myfelf fufficiently recompenfed, and am, I Gentle7nen^ with the highefi Rfieem^ your mojl Obedient hmnble Servant^ »* 4W. Watson^ ERRATUM. P. 4* L. 6. for freezings read Freeze*