VOL. XLIII.] PHILOSOPHICAL TRANSACTIONS. 153 



experiments, as before observed, were made last Friday night, the air being per- 

 fectly dry. Sunday proved wet, and Monday somewhat warm ; so that the air 

 was full of vapour, wind south-west, and cloudy. Under these disadvantages, 

 on Monday night, he attempted again the experiments ; they succeeded, but with 

 infinitely more labour than the preceding, because of the unfitness of the evening 

 for such trials. 



April 15, wind e.n.e.; about 4 o'clock in the afternoon, Mr. W. fired the 

 spirit of wine 4 times from the poker, as before, 3 times from the finger of a 

 person electrified, standing on a cake of wax, and once from the finger of a 

 second person standing on wax, communicating with the first by means of a 

 walking-cane held between their arms extended. The horizontal distance in this 

 case between the glass tube and the spirit was at least 10 feet. 



There is the repulsive power of electricity, as well as the attractive ; so that 

 we are able, when a feather, or such like substance, is replete with electricity, 

 to drive it about a room, which way we please. This repulsive power continues, 

 till either the tube loses its excited force, or. the feather attracts the moisture 

 from the air, or comes near to some non-electric substance ; if so, the feather is 

 attracted by, and its electricity lost in, whatever non-electric it comes near. In 

 electrified bodies, we see a perpetual endeavour to get rid of their electricitv. 

 This induced Mr. W. to make the following experiment. 



He placed a man on a cake of wax, who held in one of his hands a spoon with 

 the warm spirits, and in the other a poker with the thread. He rubbed the 

 tube among the thread, and electrified him as before. He then ordered a per- 

 son, not electrified, to bring his finger near the middle of the spoon ; on which, 

 the flash from the spoon and spirit was violent enough to fire the spirit. This 

 experiment he then repeated 3 times. 



In this method, the person by whose finger the spirit of wine is fired, feels 

 the stroke much more violent, than when the electrical fire goes from him to 

 the spoon. This way, for the sake of distinction, we will call the repulsive 

 power of electricity. 



The late Dr. Desaguliers has observed, in his excellent dissertation concerning 

 electricity, " that there is a sort of capriciousness attending these experiments, 

 or something unaccountable in their phenomena, not to be reduced to any rule. 

 For sometimes an experiment, which has been made several times successively, 

 will all at once fail." Now Mr. W. imagines that the greatest part, if not the 

 whole of this matter, depends on the moisture or dryness of the air; a sudden 

 though slight alteration in which, perhaps not sufficient to be obvious to our 

 faculties, may be perceived by the very subtle fire of electricity. For, 1st, he 

 conceives that the air itself, (as has been observed by Dr. Desaguliers) is an 

 electric per se, and of the vitreous kind; therefore it repels the electricity arising 



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