24 



EXPEUIMKNTS WITH IONIZED AIK 



tlimensious (resistance to flow) of the influx tube. The dust density which actually 

 reaches tlie jet is determined Ijy a ratio of the volume of the air inflowingat 6", and 

 due to the action of the steam jet, and the volume of the charged air inflowing from 

 P, determined by the pressure of the aspirator. In this respect also must the api»a- 

 ratus be left unaltered if the data are to be compaiable. Hence, when the air is 

 taken from without the room in wintei', the rush of air through the cuK)i' tube 



Fio. 5. — Chart Showing Margins of the Opaque Field in Terms of Air Temperature and Steam 

 Pressure. Fig. 6. — Chart Showinc. Margins of thf. Colored Fields in Terms of Temperature and 

 1'kf.ssure. 



will be increased by the natural draught under which the air enters. As a result, 

 the dust content is diluted, caDt. par. This discre2«inc)' is quite observable, and the 

 colois show an uncertaint)' and flicker, due to bad mixtuie. Hence these results are 

 discarded in the chart. Again, the difl'erence between a warm and a colder room 

 implies a diiference in the ionizing activity of phosplioi-us. 



G. Cohr MargiiiJi and Distrihutioii. — In endeavoring to find the effect of tem- 

 perature and. pressure on the disti'ibutiou of color in question, the diagram woi'ked 



