442 PHILOSOPHICAL TRANSACTIONS. [aNNO 1778. 



explosion in one case, and the non-explosion in the other, depended wholly on 

 the different quantities to be thrown off: whence it will follow that though a 

 small quantity of electricity will pass off silently on a point, yet that this power 

 is very limited ; for that if a somewhat greater quantity be applied suddenly to 

 a sharp point, it will not pass off silently, but create an explosion in proportion 

 to its density. 



I cannot omit the opportunity here offered, of remarking the unfairness of 

 the insinuations that have been thrown out to the prejudice of Mr. Wilson, 

 Had there been any juggle in making his experiments, it would certainly have 

 been detected by the committee appointed to examine them. And in case of 

 such a detection, it was the duty of the committee to lay open the imposture 

 both to the society and the public. Instead of which, instead of disputing or 

 even doubting the fairness of them, they have in a manner admitted it, by only 

 saying in their report, that they appear to be inconclusive. This, I say, is ad- 

 mitting the facts to be fairly stated : unless we could suppose their regard for Mr. 

 Wilson, and tenderness for his reputation, had induced them, after detecting 

 the fallacy of his experiments, to pass it over in silence ; of which improper 

 partiality I do not know that they are so much as suspected. What therefore 

 the committee, after a strict scrutiny of the matter, did not think themselves 

 warranted to say, I take for granted they would not insinuate ; and that there- 

 fore such insinuations can only arise from the levity of more obscure persons, 

 puzzled perhaps by the seeming contradiction between Mr. Wilson's experiments 

 and those of Mr. Nairne, and too impatient to investigate the real causes of 

 that difference. I am persuaded however, that the known property of sharp 

 points to carry off electricity silently, when the quantity is small, together with 

 that other principle, which I apprehend I have here established, that they cease 

 to do so when the quantity is large; that these two (taken together) will clear 

 up the whole difficulty, and account for Mr. Nairne's experiments, without any 

 impeachment to those of Mr. Wilson. 



I have already had occasion, in the course of this argument, to consider 2 

 of those experiments, of which therefore I shall say no more ; but proceed, 

 without further digression, to examine those that remain. The first I shall 

 mention, is that in which the prime conductor being previously charged with 

 electricity, a sharp point is presented to it within the attracting, and without the 

 exploding distance, and then brought slowly on towards it. In this case no ex- 

 plosion follows ; neither is there any reason to expect it should, because the 

 quantity of electricity is gradually diminished by the approach of the point, so 

 that when it comes within the striking distance, there is not enough left to make 

 an explosion. 



Again, when an intermediate conductor is used, terminated at each end with 



