THE STUUCTITRE OF THE NUCF-EUS. 



131 



TABLE 24 — Continued. 

 (3) Oiher solvents than water 



SUMMARY AND INFERENCES. 



42. Values of the nudeation, n. — The amiiber of nuclei geiieiuteil uiidei- iden- 

 tical conditions of agitation varies with the violence of the agitation and the bidk 

 of solution used, and, fi-om a theoretical point of view, particidarly witli the con- 

 centration of the solution and its chemical nature to the extent of a discriiiiinati()n 

 between saline and neutral organic solutes. The first two factors indicate an origin 

 of the nuclei within the liquid. So far as concentration alone goes, one may write, 

 ^; _ n _j- J./(log B/c), where n is the number of nuclei produced per cub. cm., 

 under otherwise like conditions, //„ the number in case of uifinite dilution (watei-), 

 c the concentration, and A and B constants. If absolutely pure water were avail- 

 able, it is probable that «„ would vanish. The degrees of dilution effective recall 

 the sensitiveness of electrolytic phenomena. For organic neutral solutes, the 

 number of nuclei is not only smaller as a rule, but they are ciiaracteristically 



fleeting. • 1 1 



So far as examined, solutions of the same class (saline or neutral), with the 

 same mass of solute per cub. cm. of solvent, generate about the same number of 

 nuclei if identically agitated. . 



43 Values of the absorption velocity, h—AM uuclei gradually vanish in the 

 lapse of time, except in those cases where the solute produces nuclei spontaneously, 

 as in the emanations from CS^, naphthalene, etc. But the rates of evanescence are 

 very different. This evanescence of nuclei is not due to evaporation except in case 

 of pui'e water. When the nuclei are fleeting, this quality must be otherwise ex- 

 plained From the marked diffusion of nuclei (Chapter VI), their dimensions 

 must be comparable with molecular dimensions. Subsidence is out of the question. 

 The nucleus is not large enough to admit of symmetrical molecular bombardment, 

 and it is to the unilateral character of this bombardment that the nucleus owes its 

 velocity. 



