on the Emanation of Phosphorus. 335 



One may argue, therefore, that the nuclei as first produced 

 are but weakly ionized in spite of their maximum condensa- 

 tional activity. As temperature rises, the latter property of 

 the nucleus declines, but the ionization increases as far as about 

 20°. Thereafter both properties decline. As the number of 

 nuclei decreases from the reaction at 13° onward with increas- 

 ing temperature, one may infer that the ionization increases 

 with temperature ; from another point of view, that the ioni- 

 zation increases as the property of the nucleus to induce con- 

 densation diminishes. It is then with the nearly non-ionized 

 nucleus that the maximum of condensational activity resides, 

 just as if ionization were the result of a dissociation or a dis- 

 aggregation of the nucleus. 



13. Electrical experiments repeated. — It is doubtful whether 

 the color experiments can be much improved. These results 

 are bound to lack sharpness ; but the electrical experiments are 

 open to further development in the first place by retaining a 

 constant velocity d V/dt throughout. This may be done by 

 inserting a second stopcock, F (not shown), to check the air 

 current to a fixed value, even when F, figure 1, is quite open. 

 In the second place the weakly ionized emanation at low tem- 

 peratures should be tested directly as to its condensational 

 power. One may inquire whether the reduced condensing 

 power of the positive and the negative ionizations differ ; 

 whether at a given temperature definite ionization is obtainable 

 quantitatively, etc. 



In Table III results obtained by the same method as above 

 are summarized for brevity. The volumes, d V/dt (liters/ mm.), 

 of air charged with phosphorus emanation traversing the con- 

 denser, are a nearly constant quantity in view of the second 

 stopcock already mentioned. 6 is the temperature at which 

 the fall of potential, ds/dt, was observed, s being the deflection 

 in scale parts of the electrometer used above. The condenser 

 was given a positive and a negative charge alternately, with 

 the outer face put to earth. Four readings for the negative 

 charge were included between similar sets for the positive 

 charge. The conduction of the insulators is given. The last 

 column contains the datum x — — (ds/dt) /s . 



14. Discussion. — The initial currents (x) are shown in the 

 graph, figure 7. As a whole the results are much more defi- 

 nite than in figure 6, seeing that no reduction for volume dif- 

 ferences is now needed. Though there is a small difference 

 between the currents corresponding to the positive and the 

 negative charges, this difference lies within a scale part and 

 may be taken as an error of observation. The position of the 

 maximum of nuclei is again shown at c. The range of the 

 new data after deducting the error in insulation is smaller than 



