592 



SCIENCE. 



[N. S. Vol. I. No. 22. 



the inside of the funnel the negative 

 electrification of e was largelj' increased. 

 So it was also when the shower, after falling 

 freelj' down the middle of the funnel, im- 

 pinged on a metal plate in metallic com- 

 munication with the funnel, held close under 

 its mouth, or 10 or 20 cm. below it. For 

 example, in a series of experiments made 



volt in five minutes with no obstruction ; 

 and 6.78 volts in live minutes with the 

 metal plate held below the mouth as before. 

 § 8. These results, and others M'hich we 

 have found, with manj^ variations of de- 

 tail, confirm, by direct test of air drawn 

 away from the neighborhood of the water- 

 fall through a narrow pipe to a distant 



i < ' Loch Kairliie Supply 



last'Monday (March 25), we found .28 of a 

 volt in 15 minutes with no obstruction to 

 the shower ; and 4.18 Ai'olts in five minutes, 

 with a metal plate held three or four centi- 

 meters below the mouth of the funnel; the 

 au- being drawn from the upper outlet (p). 

 Immediately after, with p closed, and air 

 dra-WTi from the lower outlet ( m ) ,but all other 

 circumstances the same, we found .20 of a 



electrometer, Leuard's conclusion that a 

 preponderatingiy strong negative electrifi- 

 cation is given to the air at every place of 

 violent impact of a drop against a water- 

 surface or against a wet solid. But they 

 do not prove that there is no electrification 

 of air bj' drops of water falling through it. 

 We always found, in every trial, decisive 

 proof of negative electrification; though of 



