EXPERIMENTS WITH IONIZED AIR. 



n 



This arrangement loses but little of its activity when the brush aS' is enclosed 

 in a glass bottle, B, liguve 17, whei'e the well-insulated terminals are sealed in 

 place by a plug of paraffine. The whole is placed within the wide vessel A, with 



FIGS 16 17.-C0MPLETED Electrical Ionizers. Scale i F.o. iS.-X-Rav Ionizer. Scale „. Fig. 19. 

 Apparatus for Testing the Persistence of Nuclei. Scale \. Fig. 20.-L0NG Tubes (Oo feet), for TEsr- 

 iNG Persistence. Scale i^. Fig. 2i.-Ultra-Violet Ionizer. Scale h 



an external condenser surface added and put to earth. The neck of A dips into 

 the influx pipe C oi the color tube. In the dark, radial streamers of great beauty 

 pass between the vessels, A and B. All brushes are within the outer vessel 

 and the effect is not changed by a coating of parafliue, the glass being 3-4 miUims. 

 thick. 



