Nolan and Enkight — Electrification Produced by Breaking up Water. 9 



that, as the size of the drops in the spray becomes smaller, the electrical separa- 

 tion occurs with greater and greater facility, especially in the case of pure water, 

 until the average size of the drop reaches a certain value (radius = 6'5 x 10"^ cms.). 

 At this stage there is a definite check. The further stages of the curve show, in 

 the case of the two less pure sainples, a tilt up, suggesting, as we have said, that 

 they will fuse with the curve for the purer water. 



In examining these curves we must consider to what extent they may have 

 been effected by certain actions going on in the spray, which we have neglected up 

 to the present, viz., electrical recombination and recombination of drops. The ions 

 carrying the negative charge are not immediately separated from the spray. Some 

 amount of recombination will take place, and the measured electric charge on the 

 water will be correspondingly reduced. There may be two types of recombination. 



Z4xl0 



100 200 300 100 



AREA OF WATER-SURFACE IN 

 Fig. 4. 



500 600 



SQ. CMS PFR CC 



yoo 



an initial type resembling (but on a different scale) the initial recombination, 

 postulated in connexion with o-particle ionisation, and a type corresponding to 

 later stages. If anything of the nature of the first type exists, it is probably 

 beyond the range of detection in any of our experiments, and consequently does 

 not influence the shape of our curves. The second type of recombination is 

 certainly operative, but its effect may not be very great in this case, where the ions 

 are carried away rapidly by the air-blast, while the drops sink steadily towards 

 the receiver. It has been found^ that the ions from a water-spray, examined as 



I J. J. Nolan, Royal Irish Acad. Proc, A, 33 (1916). 



SCIENT. PKOC. K.D.S., VOL. XVH, NO. I. 



