238 Silk Manufacture. 



was placed within a black one of similar quality; first with the 

 right side of one contiguous to the wrong side of the cvher, and 

 afterwards with the two rough surfaces touching each other: in 

 the first case they raised nearly nine pounds, and in the second, 

 the still more surprising weight of fifteen pounds, without separat- 

 ing their surfaces. The tufts and ends of silk which are gener- 

 ally found on the inside of stockings considerably assisted towards 

 the result of these experiments, which were not -learly so striking 

 after these tufts were removed. 



' In the course of his experiments, Mr. Syr imer also discov- 

 ered that black and white silk, when highly electrified, not only 

 cohere to each other, but will also adhere to any broad, and to 

 any polished surfaces, even although these bodies should not be 

 themselves electrified. Having undesignedly thrown a stock- 

 ing out of his hand, it struck against the side of the apartment, 

 and adhered to the paper hangings. He repeated the experiment, 

 and found that the stocking would continue its adhesion for near- 

 ly an hour. Placing a black and while stocking against the wall 

 in this manner, he applied the two others to them, which had 

 previously been highly electrified; and putting the white to the 

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

 wall, each of them hanging to that which had drawn it from its 

 situation. When the stockings were applied to the smooth sur- 

 face of a looking glass, they adhered even more tenaciously. 



' Similar experiments, combining a greater variety of circum- 

 stances, were afterwards made with white and black ribins by 

 Mr. Cigna of Turin, an account of which was published in the 

 Memoirs of the Academy of that city for the year 17G5. 



' Having dried before the fire two white silk ribins, and ex- 

 tended them upon a smooth plane, he then several times drew over 

 them the sharp edge of an ivory rule, and found that both ribins 

 had by this friction acquired sufficient electricity to adhere to the 

 plane, although they gave no indications of being in this state of 

 excitement during their continuance upon it. It was not at all 

 material to the success of the experiment, whether this plane was 

 itself an electric or non-electric substance. When taken up sep- 

 arately, the ribins both appeared to be resinously electrified, and 

 repelled each other: on dividing them, electric sparks were per- 

 ceived between them, but on being again forced together or placed 

 on the plane, no sparks were given off until they had been again 

 excited by friction. When by means of the ivory rule they had 

 thus acquired the resinous electricity, if, instead of being replaced 

 on the smooth body whereon they had been rubbed, the ribins 

 were applied to a rough conducting surface, they would on their 



