308 PHILOSOPHICAL TRANSACTIONS. [anNO I747. 



of Mercury's apparent path with the ecliptic, was 8*^ 26'. The planet's latitude 

 at the ingress lO' 57", at the conjunction 9' 10", at the egress 6' 59". The 

 planet's horary motion 5' 56"; and the inclination of its orbit 7' 5". 



Observations on so much of Mans, le Monnier the youngers Memoir, lately pre- 

 sented to the Royal Society * as relates to the Communicating the Electric Vir- 

 tue to Non-electrics. By Wm. IVatson, F. R. S. N° 482, p. 388. 



One of the questions proposed to be examined is, in what manner the electric 

 virtue is to be communicated to such bodies as yet have it not, and which are not 

 capable of acquiring it by bare friction only ?" M. le Monnier observes on this, 

 " That no other manner is known, by which the electric virtue may be com- 

 municated, besides the near approach of a body actually possessed of the same : 

 that the rule laid down by M. du Fay, That bodies never receive electricity by 

 communication, unless they are supported by bodies electric in their own nature 

 does not always take place ; and that it is liable to great exceptions : for, first in 

 the Leyden experiment, the phial filled with water is strongly electrified by com- 

 munication, even when carried in the hand, which is not a body electric by 

 nature." 



To this Mr. Watson answered, that M. du Fay's rule is confirmed by all the 

 experiments yet made public, and even by that of Leyden quoted by our author, 

 or what is usually called that of Muschenbroeck. For, in this experiment, is 

 not the non-electric water contained in and supported by the glass phial, which is 

 electric in its own nature? Its being carried in the hand is no more than its being 

 placed on any other non-electric body, and therefore is no proof against the gene- 

 ral position. It is well known, that if the phial be made non-electric by wetting 

 its outside, so as not to leave some inches perfectly dry, between its mouth and 

 that part which is wetted, the water and phial part with the electricity as fast as 

 they receive it, unless it is stopped by another electric per se. 



Secondly, Our author mentions, " That all bodies which are electrified by 

 means of a phial of water fitted to a wire, and which has already received a great 

 deal of virtue by communication ; all bodies, he says, placed in any curve line, 

 connecting the exterior wire and that part of the bottle, which is below the sur- 

 face of the water, acquire electricity without being placed on resin, silk, glass, or 

 the like : that thus a violent concussion may be given to 200 men all at once ; 

 who holding each other by the hand form the curve just mentioned, when the 

 first holds the bottle, and the last touches the wire with the end of his finger ; 

 and this equally, whether they are all mounted on cakes of resin, or stand on the 

 floor : that the electricity has in this manner been carried through a wire of the 



* See Phil. Trans., N" 481.— Orig. 



