Resistance of iron wire and salt water compared 285 



It was found that when it passed through 5-2 inches the shock was sensibly 

 greater, and when it passed through 8-4 sensibly less than with the large one, 

 so that it is supposed it would be equal if it passed through 6-8. 



44 



i -08 



6-8 



44i 250 

 so that the resistance should seem as the ro8 power of the velocity. 



N.B. The quantity of water which the tubes held was not measured very 

 exactly. 



575] The tubes used in p. 123 [Art. 574] were measured by 

 follows : 



and are as 



37 inches of the 9 first tubes, which are what was used in p. 123 [Art. 574], 

 held together 3373 grains, therefore the shock was very nearly the same, but if 

 anything rather greater when it passed through one tube, 37 inches of which 

 held 3480 grains of $, than when it passed through 9 tubes, 37 inches of all 

 which together held 3373 grains. 



By p. 124 the shock is as much diminished in passing through 6-8 inches 

 of a tube, 37 inches of which hold 567 grains, as through 44^ of one, 37 inches 

 of which hold 3480, so that resistance should seem as the 1-03 power of the 

 velocity. 



576] Comparison of diminution of shock by passing through iron wire or 

 through salt water*. 



In order to compare the conducting power of iron wire and salt water, the 

 shock of two jars had its choice whether it would pass through 2540 inches of 

 nealed iron wire, 12 feet of which weighed 14-2 grains, or through my body, 

 each end of the iron wire being fastened to a pretty thick piece of brass wire 

 which I grasped tight, one in one hand and the other in the other, and with 

 them discharged the jars. 



* [Art. 398 and Note 32.] 



