ON ELECTRICAL ATTRACTIONS AND REPULSION8, 3J5 



jji rotatory motion, and a circular motion round the plate; 

 aud if the experiment be made in the dark, the ball will 

 appear luminous in every point in which it successively 

 touches the ring," 



This experiment singularly confirms the inferences I de- General infer- 

 duce from my experiments, that the nonconducting state of ence(? ' 

 glass is owing only to the powerful affinity of composition 

 of the component particles of good glass ; and that when a 

 powerful affinity, or the concurrence of several, presents it- 

 self to this substance, the latent igneous fluid is set in mo- 

 tion, and it becomes a conductor, or a body supersaturated 

 with the electric fluid. When it presents itself iri this state 

 to a body, that has a strong affinity for the fluid which 

 supersaturates it, it yields it up ; but when the action is 

 stronger, and burns, it is decomposed like all other sub- 

 stances; witness the long and continued action on the 

 points of my conductors, and that of the solar rays on the 

 glass of our windows. We see above, that tke author re- 

 cjuires the ball of glass to be very thin*: this is a neces- 

 ary condition for producing the rotatory and revolving mo- 

 tion, for every thing made of glass in this state is moved by 

 the slightest electric action ; it kindles, as it were, like char- 

 coal befqre the blowpipe ; and being moved in one point, 

 the neighbouring points tend by affinity to carry themselves 

 in succession to the centre of activity. This is the natural 

 way in which I explain these phenomena according to my 

 manner of seeing them ; perhaps by the idola specus of 

 Bacon. But, si quid novisti rectius istis, candidus im- 

 perti — I seek only truth ; this alone guides my pen, and in 

 seeking it I write comment a, which perhaps time will efface. 

 So many have been made of this kind in all countries, that 

 the ancient Belg'mm cannot expect to be alone exempt from 

 them. 



* My conductors, when they are of thin glass, become excellent onts 

 in less than a few hundred turns of the machine. 



XVII. 



