18 THE STRL'CTURE OF THE NUCLEUS. 



111. (Jorvobonitive exper/'me/itv iciOt damp paper. — Another nietlioil of throwing 

 light oil the iiKiuiry will be a comparison of the conduction produced in the 

 condenser by air passing over damp filter paper with the corresponding case of air 

 passing over phosphorus. 



Table 9 shows lesults contrasted in this way. L is the number of liters of air 

 aspirated over the body and passed through the condenser, rt?6/J/ the corresponding 

 currents in arbitrary units at the times stated. Fi'om these {<is/dt)o/sQ is found. 

 The degree of insulation of the condenser is also tested successively, both with 

 dry air currents in the absence of ionizers and with the air currents following 

 in the absence of ionizers. The wet [)aper behaves in a less intense way something 

 like the phosphorus in the second part of the table. The rise of conduction, how- 

 ever, is erradual, the conduction at best moderate and the leturu of the condenser 

 to the original degree of insulation relatively rapiil. With phosphorus, the con- 

 duction after the first minute or so has risen to the inuneasurably large values and 

 when the air current ceases the condenser shows similar ctmductioii. Much more dry 

 air is needed to desiccate the condenser and the phosphorus to normal values (fully 

 twice as much as in the preceding case). Eventually the currents also return to 

 the normal, relatively small limit and the insulation of the condenser is nearly 

 pei-fect again. 



Qualitatively, the two phenomena lun \n parallel ; quantitatively, they are 

 enormously different. Inasmuch as the paper is obviously wet, whereas the phos- 

 phorus grid has been dried short of the desiccator, inasmuch as any emanation 

 must behave like a water evaporation, I think that the volatile body is probably 

 of the nature of a hydrophosphide. Some electrically active substance is distilled 

 in the presence of moisture and precipitated in the condenser. 



•_'0. (Jo7-rohorati've experiments with desiccators. — The final test made to detect 

 the character of the emanation was one of direct desiccation over chloride of cal- 

 cium, l)efore insertion. The day happened to be damp and the insulation poor. 

 The exjierinients, however, are none the less detiiiitf. 



(1) Phos[>horns dried in air and inserted into the dried tube of the water 

 bath, ah, figure 1. The condenser was at once discharged on passing the air 

 current through it. On removing the phosphorus the condenser showed too large 

 a leakage to admit of the measurement of current. All appurtenances were now 

 dried in a current of dry air and the final insulation determined. 



(2) The phosphorus grid, having been placed for about 15 minutes in the 

 desiccator was again inserted into the tube, ah. The current now obtained was 

 d.^/dt = 'dl : the insulation proved to be ds/dt = W. Hence the current due to 

 ionized aii' was but ds/dt^l, and abnormally small value, but indicating the 

 absence of moisture. 



The phosphoi'us grid was once more jmt in the desiccator for 15 minutes. 

 After replacing it in the water bath the curient observed was 40; the insulation 27. 

 Hence the leakage due to ionized air is here ds/dt=z 1,S, agreeing with the usual 

 ordei' of ionized values above. 



Owing to the unfavorable condition of these experiments, not much definite- 



