Spontaneous Crystallization of Supercooled Liquids. 89 



see that 17 minutes were required for the number of crystal- 

 lizations to increase from 19 to 32 — that is, the average life 

 is in this case about 8 minutes *. 



Similar calculations yield a fairly consistent picture for 

 the whole series o£ experiments ; thus : — 



Average life, in minutes, of tubes containing particles 

 whose radius differs from the equilibrium size by 



Temperature 

 experiment. 



of 



0-10 p. c. 



10- 



-20 p. c. 



-V- 



10- 



-30 p. c. 



30-40 p. c. 



33°-4 .... 





3 





13 







75 



360 approx 



31°-3 .... 





2 





10 







32 



290 approx 



23°-9 .... 





2 





9 







52 



670 approx. 



19°T .... 





4 





80 app 



•ox. 









It is evident, therefore, that as the discrepancy between 

 the radius of the particle of equilibrium size and the radius 

 of the particle present inci eases by equal fractions,, the 

 average life increases more or less geometrically. 



As we have said, the tubes of diphenyl amine were of 

 variable activity and showed an initial increase. Although 

 their behaviour was in accordance with the theory suggested, 

 it made a series of comparative measurements difficult. 

 Exactly the same general relations however appeal', as 

 is shown by the following numbers, which refer to an 

 experiment at 34 o, with 133 tubes : — 



Time, Number of 



in minutes. crvstallizations. 



1 " 31 



4 39 



1G 47 



55 "49 



80 54 



95 56 



1340 63 



The calculations of particle size, etc., are not given, but 

 lead for the above experiment to the following result : — 



Discrepancy between equilibrium size 

 and size of particle present. 



I -10 per cent. 10-20 per cent. 20-30 per cent. 

 Average life, in minutes ... 6 approx. 50 approx. > 700 



i. <?., the same son of relation as previously found with 

 p.-toluidine. 



* The justification for calculating- the average life in this simplified 

 way is the rapidity with which the number of crystallizations in 

 successive intervals of time falls off. 



