YOL. XLIVJ PHILOSOPHICAL TKANSACTIONS. SOQ 



length of 3000 toises, or near 2^ English miles ; part of which wire dragged on 

 wet grass, went over hedges, palisados, and over land newly ploughed up." 



The experiments in the 2d argument do nowise invalidate M. du Fay's rule; 

 for their success depends on keeping whatever forms the curve line mentioned by 

 our author, whether it consists of men or wire, in a non-electric state : and if 

 whatever forms this curve line acquires any degree of electricity more than its ori- 

 ginal quantity, which it is well known may be done by being placed on originally 

 electrics, the effect of the shock is proportionably lessened. Tlius, if a man, 

 standing on electrics per se, apply his hand to the phial of water, suspended by 

 a wire to the electrified gun-barrel as usual, this person will acquire electricity, 

 which will be sufficiently perceptible in him, by his attracting light substances 

 held near his body, or by his firing inflammable ones, when properly presented 

 to him; if a person then thus electrified, by applying one of his hands to the 

 phial, touch the electrified gun-barrel with a finger of his other, let the phial be 

 ever so strongly electrified, he feels but a slight stroke; and this stroke is greater 

 or less, as the difference of the accumulation of electricity in the body of the 

 man, and that of the water in the phial. Thus we know from experiment, that 

 though a considerable quantity of the electricity, in impregnating the phial of 

 water with it, per\'ades the glass, yet the loss of it in this way, is not equal to 

 what comes in by the wire : therefore we will, for the sake of a more easy method 

 of explanation, suppose that the phial, when electrified in the most perfect man- 

 ner, contains a quantity of electricity equal to 10 ; that the man's body, by 

 standing on wax, and touching the phial with one of his hands during its electri- 

 fication, contains a quantity equal to 7 : on his touching the gun-barrel with a 

 finger of his other hand, he will receive a small stroke only equal to 3, the differ- 

 ence of the electricity of the water and that of his body : and if he touch the 

 gun-barrel again, without removing his foot from the originally electric, the 

 stroke will be scarcely perceptible, on account of his body being nearly of the 

 same degree of electricity with the water in the phial. So that here we see that 

 the violence of the shock, to be felt by whatever fonns the curve line, depends on 

 its being, in the most perfect manner, free from any degree of electricity more 

 than the original quantity ; which is contrary to the opinion of our author. 



Thirdly, M. Monnier tells us, " That the water of the basin-of the Thuilleries, 

 whose surface is about an acre, has been electrified in the following manner : 

 There was stretched round half the circumference of the basin an iron chain, 

 which was entirely out of the water; the two extremities of this chain answered 

 to those of one of the diameters of the octagon : an observer, placed at one of 

 those extremities, held the chain with his left hand, and dipped his right at the 

 same time into the water of the basin ; while another observer, at the opposite 

 side of the basin, held the other end of the chain in his right hand, and a phial 



