VOL. XXVI.] PHILOSOPHICAL TRANSACTIONS. 413 



there was no motion till it arrived within about an inch of them. And thus on 

 several trials it answered much alike. And if at the same time the sand be 

 suddenly shot out, the tube would attract ihe same bodies at double or treble 

 the forementioned distance, without any fresh attrition; which plainly shows 

 that although the tube will attract when approached near, yet the body within 

 is a sensible impediment to the extension of its action without. This brings to 

 my mind the unsuccessfulness of the attempt I made to attract bodies with a 

 tube exhausted of its air; which seems to conclude, there being no air within 

 to bear the effluvia from its body, a continuity of their parts must consequently 

 be prevented. 



Some Experiments showing Electricity and Light producible on the Attrition of 

 several Bodies. By Mr. Fr. Ilaukshee, F.R.S. N° 3J5, p. 87. 



I caused a piece of wood to be turned into the form of a short cylinder, about 

 4 inches in diameter, and 3 in length. This being tixed on an axis, I melted 

 in a ladle about a pound and a half of the best sealing-wax I could procure, and 

 when fluid I plunged the wooden cylinder into it, where I kept it moving round 

 till it had got a coat of wax about half an inch thick on its surface, (I mean that 

 part of it which is most remote from its axis) : when it was perfectly cold, I 

 placed it on the machine, which gave motion to it by a large wheel, as usual in 

 the experiments on the attrition of the glass globe; after the motion and attri- 

 tion had been continued for some small time, I held the ring of threads over 

 the cylinder, on which they were attracted and directed towards its centre, as in 

 the like experiment made with the glass globe. The threads likewise, while 

 they continued directed, would fly the approach of a finger. Thus in all re- 

 spects relating to electricity, the effluvia of wax seems very agreeable to those 

 producible on the attrition of glass: for, on rubbing a stick of the same wax, 

 the brass leaf would be attracted and returned with great velocity ; and some- 

 times a piece of the same brass might be carried all about a room, seemingly 

 riding or floating on the surface of its effluvia. In short, I find no difference 

 in the laws of the different effluvia, though those of glass seem to be much the 

 strongest, and to act with the greatest vigour. 



On the approach of night, I caused the same motion to be given to the wax 

 cylinder, as I had done in the day time, to see what light might then be pro- 

 duced on its attrition. I applied some clean new flannel on it, but could dis- 

 cover little or no light: yet afterwards, on holding my naked hand, as usual, 

 on the glass globe, a considerable light was visible, though only where the at- 

 trition was made, nor would it continue any longer than the motion. I tried if 

 a light would be communicated to one's finger, and approached near it, as in the 



