334 O. Uarus — Effect of Temperature and of Moisture 



— x = d(\og s)/dt, but the approximate method of computing 

 ds/dt from observations 15 seconds apart is more convenient. 



The corrected values of — x =(ds/dt) /s , when dV/dt is 

 •45 and 1*00 liters per minute, respectively, are given in the 

 graph, figure 6. Different dots correspond to different series. 

 The curves are smoother than the uncorrected results would 

 have been, and the values for low efflux are naturally more 

 certain. For apart from instrumental difficulties, there is at 

 high velocities a danger of interfering with the temperature 

 of the ionizing phosphorus. Swift currents are not so easily 

 cooled in the water bath and intense action of the ionizer con- 

 tributes its own temperature error. In both curves the con- 

 duction of the insulators prevents the curves from actually 

 reaching the abscissa. 





w 





Ftg.5. 



mr 



Ur 



Jl<).,° 



4 ° 



15' 



BO" 



Z5° 



scr 



sr 



12. Contrast with the color data. — The character of these 

 curves may now be examined in comparison with the color 

 data of figures 3 and 4, the latter being specially available. In 

 both there is a rise of activity from about 9° through a maxi- 

 mum, and an eventual less pronounced decline of activity 

 toward 35°; but in their details, the two sets of curves are 

 very different. The nuclei of figure 3 are suddenly produced 

 in maximum concentration at about 13° C, as suggested by 

 the arrows c in figure 6 et seq. ; they then decline in number 

 regularly and very gradually as far as observed. In figure 6, 

 however, the ions show a gradual increase of number, even as 

 far as 20°, after which their number also falls off to the limits 

 of observation. 



