Chapter I: AM the more particular in this, being willing to save the Labour of

those, who are desirous of making these Kind of Trials; for although some of the lesser Experiments may succeed almost at any Time, yet I never could find that the more remarkable ones would succeed but in dry Weather.

_I am, Gentlemen,_
_Your most obedient,_
_humble Servant,_
W. WATSON.

_London, April
25. 1745._

TO THE
ROYAL SOCIETY.

GENTLEMEN,

IN some Papers I lately did myself the Honour to lay before you, I acquainted you of some Experiments in Electricity; particularly I took notice of having been able to fire Spirit of Wine by what I call'd the repulsive Power thereof; which I have not heard had been thought of by any of those _German_ Gentlemen, to whom the World is obliged for many surprizing Discoveries in this Part of natural Philosophy.

HOW far strictly speaking the Spirit in this Operation may be said to be fired by the repulsive Power of Electricity, or how far that Power, which repels light Substances when fully impregnated with Electricity, fires the Spirit, may probably be the Subject of a future Inquiry; but as I am unwilling to introduce more Terms into any Demonstration than what are absolutely necessary for the more ready Conception thereof, and as inflammable Substances may be fired by Electricity two different Ways, let the following Definitions at present suffice of each of these Methods.

BUT first give me Leave to premise, that no inflammable Substances will take fire, when brought into or near the Contact of _Electrics per se_ excited to Electricity. This Effect must be produced by non-electrical Substances impregnated with Electricity received from the exciting _Electrics per se_. But to return,

_1st_, I SUPPOSE that inflammable Substances are fired by the attractive Power of Electricity, when this Effect arises from their being brought near excited non-Electrics.

_2dly_, THAT inflammable Substances are fired by the repulsive Power of Electricity; when it happens, that the inflammable Substances, being first electrified themselves, are fired by being brought near non-Electrics not excited.

THIS Matter will be better illustrated by an Example. Suppose that either a Man standing upon a Cake of Wax, or a Sword suspended in silk Lines are electrified, and the Spirit, being brought near them, is fired, this is said to be perform'd by the attractive Power of Electricity. But if the Man electrified as before holds a Spoon in his Hand containing the Spirit, or the same Spoon and Spirit are placed upon the Sword, and a Person not electrified applies his Finger near the Spoon, and the Spirit is fired from the Flame arising from the Spoon and Spirit upon such Application; this I call being fired by the repulsive Power. Of the two mention'd Kinds I generally find the repulsive Power strongest.

SINCE my last Communication, the Spirit has been fired both by the attractive and repulsive Power through four Persons standing upon electrical Cakes; each communicating with the other either by the Means of a walking Cane, a Sword, or any other non-electric Substance. It has likewise been fired from the Handle of a Sword held in the Hand of a third Person.