Melting of Metals by Cold Ftifion. [Book IV; 



and black clouds, which had a flow motion. 3d. In 

 molft weather not actually raining. 



In rainy weather, without lightning, his apparatus 

 was always electrified a little time before the rain fell, 

 and during the time of rain, but ceafed a little before 

 the rain was over. 



The higher his rods reached, or his kites flew, the 

 fcronger figns they gave of being electrified. 



It has been intimated that the clouds are fometimes 

 pofitively, and fometimes negatively electrified. In the 

 latter cafe the lightning is fuppofed, upon the Ffankli- 

 nian theory, to proceed from the earth to the cloud. 

 The general effects of lightning are precifely the fame 

 with thofe of the electric fhock, only greatly magnified. 

 It may not be improper in this place to notice an old 

 error, namely, the melting of metals by what has been 

 called the coldfufion. The error is found to reft upon 

 certain ill attefted relations of fwords being melted in 

 the fcabbard by lightning, and money in the bag, 

 without injuring the fcabbard or the bag. A variety 

 of experiments have been accurately made to determine 

 the fact; the refulrs of which have been, that the thin 

 edge of the fword, or of the money, might have been 

 inftantaneoufly melted, and yet fo inftantaneoufly cool- 

 ed, as neither to affect the fcabbard nor the bag. A 

 very fmall wire will inftantly melt and inftandy cool in 

 the flame of a common candle. 



Mr. Kinnefley inclofed a fmall wire in a goofe quill 

 filled with loofe grains of gunpowder, which took fire 

 as readily as if they had been touched by a red hot 

 poker ; tinder was kindled when tied to a piece of the 

 fame wire ; but no fuch effects could be produced with 

 a wire twice as large. Hence it appears, as Mr. Kin- 

 nefley remarks, that though the electrical matter has 

 no fenfible heat when in a ftate of reft, it will, in pafling 



through 



