36 



KXI'K111.MK>1S WITH lOXIZED AIK. 



TABLE I (Co»/inufJ).—ABSORVTlON OF PHOSPHORUS DUST IN TUBES. GLASS. 

 DIAMETER, .26-32 cm. ^=7-10 cm. O—if. 



A brief summary of the chief re.sults is appended for reference. 



TABLE 2.— ABSORPTION OF PHOSPHORUS DUST IN TUBES. 



These re.sults are eiiteied in tlie diart, figure 3, witli greater fulness, where the 

 abscissas are the lengths of the absoiption tubes in centims., the ordiuates the 

 volumes (liters) per minute producing the fiducial blue. The curves drawn 

 through the points are computed from the theory presently to be given. For the 

 wider tubes and greater lengths, the hiirher volumes sometimes show a break in 

 the curve (cf. lead), meaning, I think, that the phosphorus ionizer is being 

 overta.xed by the quantity of charged air demanded. 



In view of the difficulty ■' of observing subject to color criteiia, the widely 

 diffei'eut values of the velocity with which the ionized air traversed the absorption 

 tubes, the high velocities employed, and the marked difference of material (conduct- 

 ing and insulating) which makes up the absorbing walls, the proximity of the values 

 of h is particulai'ly noteworthy. No relation to diameter is apparent. In case of 

 glass, of impure gray rubber, of pure brown rubbei', and of lead, this velocity h, so 

 far as observation waiTants, is the same. 



4. Tiesidtsfor wide tubes. — In contrast with these results with tubes of i-elatively 

 small bore, I shall now add data for wide tubes. These were 5 centims. in diameter 

 (2-inch drain-i)ipe of tin plate) and they may be regarded as direct prolongations of 

 the influx [»ipe, C", of the color tube. The ariangemeut is shown in Chapter I., figure 

 20. Tiie air passing thiough these tubes is moved by the suction of the steam jet 

 and is independent of the ionizing current through the gasometer. The velocity of 

 the air current through the tubes (often 50 feet long) was about 100 centims. 

 ' liters/min. "cm. /sec. ' Adding to this the variable ionizing intensity of phosphorus. 



