VOL. XXV.] PHILOSOPHICAL TRANSACTTONS. " 345 



that then they would flee and avoid a touch from it ; just as if the north pole 

 of the magnet were applied towards the south point of a needle : and at the 

 same time, if the finger be held near, at about an inch from the end of the 

 aforesaid thread, it will there seem to be attracted, removing itself somewhat 

 out of its direction to the approached body. But if any thing be held between 

 the glass and the directed thread, then the thread immediately quits hold of 

 the effluvia, and returns to its first position ; yet on withdrawing the interposed 

 body, (if it has not removed itself too far out of the reach of the effluvia) 

 it will again return to its tendency, and so remain, till the weight of its body 

 be too great for the declining strength of the effluvia to support it in such a 

 direction. I have since tried the same experiment with a globe glass, which 

 when the attrition was made, would in all manner of positions attract the sur- 

 rounding threads, directing them towards its centre. 



ExPER. II. Showing the Direction of Woollen Threads every way from the 

 A.vis, towards the Circumference of a Jricated Glass. — In order to try what ap- 

 pearances might be aflforded by placing the woollen threads on the axis within, 

 and making the attrition on the outer surface as usual, I took, a globe glass 

 about six inches diameter, and having conveyed into it some woollen threads 

 tied to a stick, which was placed in it as an axis, and being fixed on the 

 machine, the great wheel was turned, and the hand applied as usual ; but I 

 soon found the inconvenience of a glass of that form, the threads entangling 

 with each other, and there was no way to loosen or separate them ; however 

 they seemed evidently disposed, had they been at liberty, to have answered my 

 expectation. Further, on bringing my hand near the glass, which was then at 

 rest, I was surprised to see a motion of the bodies within side ; and on inquiry, 

 I found it was occasioned by the approach of my hand, since I could by a 

 motion of my finger towards the point of any of the threads that touched not 

 the inside of the glass, drive it any way ; it seemed to fly my finger held on 

 any side of it, and this without touching the outer surface by half an inch or 

 more. Now when this experiment was made by hanging the threads near the 

 outside, it was very strange, to see them fly the approach of a finger ; yet how 

 much more surprising is it, to see the same performed even when a body so 

 solid as glass interposes ; which shows the subtilty of the effluvia, the body 

 from which it is produced seeming to be no impediment to its motion : besides, 

 it seems very much to resemble or emulate a solid, since motion may be given 

 to a body, by pushing the effluvia at some distance from it : but what is still 

 more surprising is, that this body, though so subtle as seemingly to perviate 

 glass, will not, as has been before observed, affect a light body through a piece 

 of muslin : now whether the muslin absorbs the effluvia, or what other laws it 



VOL. V. Y Y 



