412 yHILOSOPHICAL TRANSACTIONS. [anNO 1759. 



hesion with each other, if another pair, more highly electrified, be separated, 

 and presented to the former still in conjunction, the black to the white, and 

 the white to the black ; in that case, the cohesion of the first pair will be dis- 

 solved, and each stocking of the second, will carry oflf that of its opposite 

 colour adhering to it. If the degree of electricity of both pairs be equal, the 

 cohesion of the first pair will be weakened, but not dissolved ; and all the 4 will 

 cohere, forming as it were one mass. If the 2d pair be but weakly electrified, 

 the cohesion of the first pair with one another will be but little impaired, and 

 that of the stockings of the 2d with those of the 1st, will be weak in propor- 

 tion. And lastly, if the 2d pair be not at all electrified, or if, in their stead, 

 any other body not electrified be presented, there will be no effect produced on 

 either hand. 



White silk and black, when electrified, not only cohere with each other in 

 the manner shown above, but when in a high degree of electricity, are found, 

 both one and the other, to adhere to bodies of broad and even of polished sur- 

 faces, though those bodies be not electrified. This adhesion he discovered acci- 

 dentally. While he was about some electrical experiments, having accidentally 

 thrown a stocking, that was highly electrified, hastily out of his hand, he was 

 surprized to find it some time after sticking against the paper-hangings of the 

 room. This led him to make the following experiments. 



He presented the white and the black silk, highly electrified, and in cohesion 

 with each other, to the hangings ; but no eflTect was produced. He then sepa- 

 rated the black from the white, and presented them singly ; in that case each of 

 them readily adhered to the hangings, which they likewise did when flung fi-om 

 a little distance, and continued there for near an hour before they dropped. 

 EEaving stuck up the black and the white, in the manner above mentioned, he 

 came with another pair of stockings, highly electrified, and applying the white 

 to the black, and the black to the white, he carried them off from the wall, 

 hanging on those that had been applied to them. When the 2d pair were elec- 

 trified, but to a moderate degree, on applying them as above, the former imme- 

 diately quitted their hold of the hangings, and dropped to the ground. The 

 same experiments held with the painted boards of the room ; and likewise with 

 the looking-glass ; to the last of which, both the black and the white silk, ap- 

 peared to adhere more tenaciously, than to either of the former. 



The late Mons. Du Fay, an ingenious member of the Academy of Sciences 

 at Paris, to whom we owe some valuable discoveries in electricity, gives an 

 account of something of this nature, in a memoir, presented in the year 1733. 

 Electricity was at that time in its infancy ; Mr. Hauksbee had a little before 

 published an account of his experiments; which brought such surprizing ap- 

 pearances of electricity to light, as could not but induce the curious to turn 



