Vacua, and on Coronoidal discharges. 



4:7i 



all along the inside surface of the large glass bulb, which is 

 below the tinfoil coating, there is a hazy luminosity which in- 

 creases with the increase of the discharge, and which to all 

 appearances is due to an accumulation of incandescent gas 

 molecules which had impinged against and were reflected by 

 the surface of the bulb. 



If the inside end of the exhaust tube e, fig. 10, is lowered, 

 so that it reaches the region of the discharge it is observed 

 that from time to time the incandescent gas shoots through 

 this tube toward the stop-cock way out of the bulb. 



EFFECT OF A BLAST ON A DISCHARGE STREAMERS. 



Granting that there is a translational motion along the path 

 of the streamer it follows that a rectilinear streamer may be 

 transformed into a curved one by imparting to the gas in each 

 part of its path a component velocity perpendicular to its 

 original velocity. This inference was confirmed by the fol- 

 lowing experiment : 



Fig J I 



Two bulbs A B (fig. 11) coated with tinfoil on the outside 

 (the electrodes of the system) communicated with a reservoir 

 (which I call the principal reservoir) by means of glass tubes 



