C. Barus — Velocity and Structure of the Nucleus. 225 



Art. XXYII. — On the Velocity and the Structure of the 

 Nucle%i8 ; bj C. Barus. 



1. Nucleation jproduced hy shaking and its velocity. — Table 

 I contains the results for the absorption velocity, k^ of nuclei 

 shaken out of dilute solutions. The data were obtained by 

 measuring the condensational coronas in a spherical vessel 

 (diameter, ^R = 30^™) in the lapse of time. If the loss of 

 nuclei be regarded as taking place at the walls of the vessel 

 and to constitute a drain on the whole nucleation {n particles 

 per cub. cm.) which moves radially outward at the rate h, then 

 the equation^ n = n^e~^^^/-^ may be assumed. The time 

 elapsed, t, is usually given in minutes. To deduce from h the 

 velocity of the nucleus, ac, I have for the present regarded it 

 as sufficient to multiply by 6 or preferably by IS/tt, so that 

 ic = 5*1 k. The concentration, c, is given in per cents or 

 grams of dry salt in 100'=''^ "^"^ of solution. It is essential that 

 a definite bulk (usually 500*=^^ '"^) be used throughout, if the 

 data are to be at once comparable. 



lBLE I. — 



Nuclei shaken out of solutions by 10 



jerks. Bulk 



of solution 



■asually 500="^ -^ jSTucleation, n = 



^^^-^kt/H. ^^^^^^ 







Concen- 



Nuclea- 



Absorption 



Nuclear 



Solvent. 



Solute. 



tration, c. 



tion, n. 



velocity, k. 



velocity, /c. 







fo 





cm/min. 



cm/min. 



Water 



Water 







32 



\'5 



7^6 









85 



6-7 



34- 









26 



9-4 



48- 



Water 



HCl 



•5 



160 



•06 



•30 







•005 



140 



•02 



•10 







•00005 



80 



2-3 



12^ 



Water 



H^SO, 



•6 



215 



•03 



•15 







•003 



130 



•07 



•36 



Water 



NaCl- 



2 



1V5 



'01 



•05 



Water 



CaCl, 



2 



240 



•04 



•20 







1 



240 









(double bulk) 



1 



460 



•04t 



•20 



Water 



FeCl, 



2 



230 











•5 



180 





._ 



Water 



Fe3X03 



1^2 



175 



•03 



•15 







•12 



160 



•03 



•15 



Water 



AI3NO3 



1-2 



200 



•07 



•36 







•12 



80 



•03 



•15 



Water 



Ca2N03 



1-4 



260 



•04 



•20 







•014 



90 



•02 



•10 







•0014 



60 



•10 



•51 



*Tliis Journal (4), xiii, pp. 91, 94, 1902. 

 f Note tbe doubled n and single k. 



