578 On Change of the Colours of Cloudy Condensation, 



different functions of promoting electrical conduction and 

 condensation. 



Chart showing the litres per minute of air nearly saturated with 

 phosphorus emanation, corresponding to the colours given as inter- 

 ferences by the abscissas. Cf. Table. Early observations with 

 simple jet" marked X. Or, denotes crimson (second order); Yl, 

 yellow ; Bl, blue ; Gr, green ; V, violet ; Op, opaque, &c. The 

 minus sign denotes light blue ; the plus sign deep blue. 



Yl, OpfA Bl. B:C & Yl z 



Ch. 



The result admits of a quantitative expression as follows : 

 From the chart it appears that colour-differences correspond- 

 ing to *06 litre/minute (blue equivalent to 1 litre/minute) 

 can certainly be detected. This amounts in the blue region 

 to about 6 per cent, of the total number of nuclei entering. 

 The potential gradient would be 2100 volts per radial centim. 

 Hence even in this strong field the total number of nuclei is 

 still overwhelmingly large as compared with the number 

 conveying current, a result which agrees with data which I 

 found in the case of spherical condensers, and is indicative of 

 the strong ionizing potency of phosphorus. 



Brown University, 

 Providence, R.I. 



