Experiments and Observations Tending to Illustrate the Nature and Properties of Electricity

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William Watson. Experiments and Observations Tending to Illustrate the Nature and Properties of Electricity

THE PREFACE

TO Martin Folkes, Esq; P. R. S

TO THEROYAL SOCIETY

TO THEROYAL SOCIETY

A Continuation of the Above

Proposition I

Proposition II

Proposition III

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THE Society having heard from some of their Correspondents in Germany, that what they call a Vegetable Quintessence had been fired by Electricity, I take this Opportunity to acquaint you, that on Friday Evening last I succeeded, after having been disappointed in many Attempts, in setting Spirits of Wine on Fire by that Power. The preceding Part of the Week had been remarkably warm, and the Air very dry, than which nothing is more necessary towards the Success of Electrical Trials; to these I may add, that the Wind was then Easterly and inclining to freeze. I that Evening used a glass Sphere as well as a Tube; but I always find myself capable of sending forth much more Fire from the Tube than from the Sphere, probably from not being sufficiently used to the last.

I had before observ'd, that although2 Non-electric Bodies made electrical, lose almost all that Electricity by coming either within or near the Contact of Non-electrics not made electrical; it happens otherwise with Regard to Electrics per se, when excited by rubbing, patting, &c; because from the rubbed Tube I can sometimes procure five or six Flashes from different Parts, as though the Tube of two Foot long, instead of being one continued Cylinder, consisted of five or six separate Segments of Cylinders, each of which gave out its Electricity at a different Explosion.

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The Knowledge of this Theorem is of the utmost Consequence towards the Success of electrical Experiments; inasmuch as you must endeavour by all possible Means to collect the Whole of this Fire at the same Time. Professor Hollman seems to have endeavour'd at this and succeeded, by having a tin Tube, in one End of which he put a great many Threads, whose Extremities touch'd the Sphere when in Motion, and each Thread collected a Quantity of electrical Fire, the Whole of which center'd in the tin Tube, and went off at the other Extremity. Another Thing to be observ'd, is to endeavour to make the Flashes follow each other so fast, as that a Second may be visible before the First is extinguish'd. When you transmit the electrical Fire along a Sword or other Instrument, whose Point is sharp, it often appears as a Number of disseminated Sparks, like wet Gunpowder or Wild-fire; but if the Instrument has no Point, you generally perceive a pure bright Flame, like what is vulgarly call'd the Blue-ball, which gives the Appearance of Stars to fired Rockets.

The following is the Method I made use of and was happy enough to succeed in. I suspended a Poker in silk Lines; at the Handle of which I hung several little Bundles of white Thread, the Extremities of which were about a Foot at right Angles from the Poker. Among these Threads, which were all attracted by the rubbed Tube, I excited the greatest electrical Fire I was capable, whilst an Assistant near the End of the Poker held in his Hand a Spoon, in which were the warm Spirits. Thus the Thread communicated the Electricity to the Poker, and the Spirit was fired at the other End. It must be observ'd in this Experiment, that the Spoon with the Spirit must not touch the Poker; if it does, the Electricity without any flashing is communicated to the Spoon, and to the Assistant in whose Hand it is held, and so is lost in the Floor.

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