1894.] 



On the Electrification of Air, 



91 



Ourvt 



4. 



f ter c 



harg 



Time in minul 



A.pri 

 ng 



April 

 'Eer charging fu gakiv 



ely c 



read 



uriny 3O 



9 __LQ. 



was 0-4 volt. 



ely d '*rin<,<30 se ?onds. 



fi2 rninuKs 



tive electrification ; though the quantity received from the machine 

 was probably less in the case of the negative electrification, because 

 the negative conductor was less well insulated than the positive. 



10. On the 21st of March, two U -tubes were put in below the 

 edge of the vat, one on either side, so that it might be possible to 

 slow dusty, or smoky, or dustless air into the vat. To one tube was 

 fitted a blowpipe bellows, and by placing it on the top of a box in 

 which brown paper and rosin were burning, the vat was filled with 

 smoky air. Again, several layers of cotton-wool were placed on the 

 louth of the bellows, so as to get dustless air into the vat. The 

 allows were worked for several hours on four successive days, and 

 we found no appreciable difference (1) in the ease with which the 

 lir could be electrified by discharges from the wire connected to 

 the electric machine, and (2) in the length of time the air retains its- 

 electrification. 



