putest pores of the most dense metals, but in a much lefs degree; and two sticks of the rareft dry hard wood, when rubb'd together will grow hot as well as metallic bodies, altho' as was before observ'd, in a much less degree. And the indefatigable Boerhaave, who had made a number of those experiments, informs us, that two gold plates may be rubb'd together till they grow fo hot, as to be just at the point of melting: The pure Air or Fire, contain'd in the minute pores of the gold, feem much more capable of receiving an intense heat, than the more grofs Air contain'd in the fenfible pores of those rare, hollow, light bodies and yet we find even that in those bodies, will grow fo hot, by means of violent friction, as to be frequently kindled into an actual flame.

;

63. The Third and principal thing to be examin'd is, whether the electrical Air be endued with the fame natural qualities and perties which are ascrib'd to Æther by Sir Ifaac Newton, &c.

pro

CHAP.

CHA P. III. PART I.

SECTION 64.

EXPERIMENTS, which fhew, that the électrical Fluid is endued with the two inherent or effential Properties of Ether, and in a moft Surprising degree, namely thofe of extreme Rarity and extreme Elafticity.

HO' almost every Experiment either illuftrates or demonftrates the great Rarity and Elasticity of the electrical

Fluid; yet none more than the Leyden Experiment, which Shock and Explosion are entirely owing to the alternate exertion of those two properties, particularly in fome of Dr. Franklin's capital Experiments, of which the following is a Specimen.

65. That ingenious and approv'd Experimentalift, in order to examine into the furprifing force of that most wonderful Phanomena of Nature, just discover'd, namely, the ELECTRICAL SUBTILE MEDIUM, had contriv'd a Device, which he call'd a magical Picture, by means of which he could ftrike a hole thro' a whole

whole quire of paper, altho' a quire of paper is thought good armour against a Sword or even a Piftol-Bullet. zd. An electrical Jack, with which he could roast meat. This, when in motion, was loaded with 100 Spanish dollars, which feem'd not in the least to retard its motion. 3d. A felf moving Wheel, which would make 50 turns in a minute, altho' above 50 Inches in circumference.

4th. By means of the force of the electrical fluid he could invert the Poles of the magnetic Needle; give a magnetism and polarity to Needles that had none before, and invert them at pleasure. 5th. He could kill a Turkey of 10 pound weight; and had once nearly kill'd himself, of which we have the following

narrative.

66. He inadvertently receiv'd the stroke of two of his large glafs Jars through his arms and body, when they were very near fully charged. It seem'd to him an univerfal blow throughout the body from head to foot, and was follow'd by a violent quick trembling in ⚫ the trunk, which went off gradually in a few • feconds. It was fome minutes before he could • recollect his thoughts, fo as to know what

was the matter; for he did not fee the flash, 'tho' his eye was on the Spot of the prime con'ductor, from whence it ftruck the back of his • hand; nor did he hear the crack, though the by-standers faid it was a loud one; nor particularly feel the stroke on his hand, tho : he

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ཟླ 1p༣༡.༡ he afterwards found it had raifed a a fwelling there, of the bignefs of half a Swan-fhot, or Piftol-bullet. His arms and the back of his neck felt fomewhat numbed the remainder of the evening, and his breaft was fore for a week after, as if it had been bruifed.

A full proof that bodies are replete with that fubtile Medium, and that the Force of the fhock is from the violent difplacing of it in the pores of grofs bodies.

67. From what he had experienced of this elaftic fire, he avers, that the greatest known effects of Lightning might be exceeded by it, fince, by his method he could obtain as great a quantity as he pleas'd.

68. Add to thefe, thofe well known Experiments mention'd by the Rev. Mr. Jones. There is hardly a motion in nature', fays that Rev. Author, which this fluid, when apply'd by a diligent Experimentalist is not capable of producing. It will give a rectilinear motion, in all directions: It will produce the motions of Rotation and Revolution. It will keep a body fufpended at a certain distance in the air, without any vifible cause, and ⚫ make it turn swiftly on its axis. It will accelerate vegetation, increase the motion of the I blood in the arteries, raife water into tides ; and in a word, will fhew itself, as a natural Inftrument, to be little less than ALL-SUF

69. N. B. Most of the above-mentioned

Experiments, when examined, appear to be perform'd by the two fore-mention'd natural properties of Æther, viz. exceffive Rarity and Elafticity, alternately exerting their contrary forces or qualities in deftroying and reftoring the equilibrium, and by that means generating

motion.

70. Our two English Worthies, viz. Lord Bacon, and Sir Ifaac Newton, were strongly poffefs'd of an opinion, that in the pores or interftices of all grofs bodies was a certain fubtile Medium in form of Air, but indefinitely more rare or fine than that, and as remarkably more elaftic and expanfive or springy. That this active MEDIUM in their pores, or SPIRIT as they termed it, was the cause of those surprising af fections and properties of motion which we fo frequently behold in inert matter. A concife account of the opinion of the former I find in the Rev. and ingenious Mr. Jones's Treatife on natural Philofophy; and that of the latter in Sir Ifaac's own Works: And firft, of the

former.

71. Mr. Jones, when treating of the doctrine of mechanical Caufes, cites the following paffages from Lord Bacon's Works to illuftrate his own opinion concerning fuch Caufes.

72. • Certain it is' (fays that noble Lord) ' that GOD worketh nothing in NATURE but by SECOND CAUSES, and if they would • have it otherwise believed, it is mere Imposture, as it were in favour towards God; and no

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