Summary of results 149 



On the whole I see no reason to think that the experiment disagrees 

 with the theory, though the middle plate was certainly more overcharged 

 than I should have expected. 



General Conclusion. 



291] The ist experiment shews that when a globe is electrified the 

 whole redundant fluid therein is lodged in or near its surface, and that 

 the interior parts are intirely, or at least extremely nearly, saturated, 

 and consequently that the electric attraction and repulsion is inversely 

 as the square of the distance, or to speak more properly, that the theory 

 will not agree with experiment on the supposition that it varies according 

 to any other law. 



292] The 2nd experiment shews that this circumstance of the whole 

 redundant fluid being lodged in or near the surface obtains also in other 

 shaped bodies, as well as in the globe, conformably to the supposition 

 made in the remarks at the end of Prop. IX [Art. 41]. These two experi- 

 ments, at the same time that they determine the law of electric attraction 

 and repulsion, serve in some measure to confirm the truth of the theory, 

 as it is a circumstance which, if it had not been for the theory, one would 

 by no means have expected. 



293] From the 4th experiment it appears, first, that the charge of 

 different bodies of the same shape and size, all ready conductors of elec- 

 tricity, is the same, whatever kind of matter they are composed of; and 

 secondly, that the charge of thin plates is very nearly the same whatever 

 thickness they may be of, provided it is very small in respect of their 

 breadth or smallest diameter ; but if their thickness bears any considerable 

 proportion to their breadth, then their charge is considerably greater than 

 if their thickness were very small. These two circumstances are perfectly 

 conformable to the theory, and are a great confirmation of the truth of it. 



294] The remaining experiments contain an examination whether the 

 charges of several different sized and different shaped bodies bear the 

 same proportion to each other, which they ought to do according to the 

 attempts made in different parts of these papers to compute their charges 

 by theory, supposing, as we have shewn to be the case, that the electric 

 attraction and repulsion is inversely as the square of the distance: with 

 regard to this it must be observed that, as in computing their charges I 

 was obliged to make use of a supposition, which certainly does not take 

 place in nature, it would be no sign of any error in the theory if their 

 actual charges differed very much from their computed ones ; but, on the 

 other hand, if the observed charges agree very nearly with the computed 

 ones, it not only shews that the actual charges of different bodies bear 

 nearly the same proportion to each other that they would do if they were 



