42S New Outlines of Chemical Philosophy. 



This experiment explains in a very satisfactory manner some 

 of the grandest phjenomena of Nature. 



If the gilt surface electrified in the manner above de5cril)ed 

 represents a cloud highly charged with electricity, and the brass 

 ball the earth, then it appears evidently,- that the cloud attracts 

 the contrary element out of the earth, at the same instant that 

 the earth attracts that contained in the cloud ; and these two 

 elements of combustion, passing through each other in contrary 

 directions, generate lightning. 



This experiment also explains the cause of water-spouts. A 

 cloud being charged with one of the elements of electricity, at- 

 tracts not only the contrary element out of the sea, but has suf- 

 ficient power to lift a portion of the water also, which at the 

 J^ame time conducts one of the elements from the cloud to the 

 sea, and the other from the sea to the cloud. And the moving 

 pillars of sand, seen by r\Ir. Bruce and other travellers, upon 

 the desert plains of Africa, are raised by the same two elemeuts. 



It may, however, be deemed. impossible that any power in the 

 clouds should be capable of raising up such heavy masses of 

 matter as those above mentioned ; but when we compare the 

 effects of a barometer-tube of only 4-lOths of an incii in dia- 

 meter, viith the effects produced by a cloud of some miles in 

 area, this o!)jection must vanish. Indeed, the effects seen in 

 o'.ir experiments are matters of astonishment quite as great, when 

 })laced in a philosophic point of view, as those produced by a 

 thunder cloud. The efficient causes are the same in both cases, 

 and ecjually unknown to us. 



Bacon and Newton showed the necessity of building philoso- 

 phical theories upon geometrical and experimental principles : 

 but these tedious mo(:les of investigation are frequently avoided, 

 by building theories upon some supposed principle, or erroneous 

 experiment made with imperfect instruments. Hence much 

 learning and ingenuity have been exercised hi building an aerial 

 fabric, which vanishes like a shadow seen through a transpa- 

 rency, as soon as the novelty is over, or on the first appearance 

 of an experimental demonstration. 



It has been a disputed point ever since electricity was brought 

 into the form of a science, whether glass is permeable by the 

 electrical fluid. This uncertainty has not been owing to the 

 want of ability or attention in those who cultivated the science, 

 but probably to the imperfection of the instruments which they 

 used hi making the experiments. 



Dr. Franklin and his friends concluded from their experiments, 

 that glass is impermeable by the electric fluid ; and this hypo- 

 thesis seems to have met \vith general approbation. 



In the year 1780, the Rev. John Lyon, of Dover, published 



some 



