﻿316 Profs. J. N. Mukherjee and B.C. Papaconstantinou on 



shows that the ratios of the values of T are independent of 

 the time or the stage of coalescence. The ultramicroscopic 

 measurements so far made show even during one experiment 

 a much greater variation in T, as will be evident from the 

 following tables : — 



Table VIII. (a). 

 (Observer : Zsigmondy.) 



Values of /3'= rTl . 



Series D. 



Series E. 



Series F, 



0-083 



0-105 



0-040 



0028 



0-058 



0-0195 



0-0302 



0-049 



0-0183 



00309 



0-0475 



0-0153 



— 



0-0403 



0-0187 



— 



— 



00126 



Zsigmondy used high concentrations of electrolyte for 

 securing a rapid rate. When the rate of coagulation is 

 slow and the duration of experiment is greater than a 

 few minutes, he found that impossible values of /3' are 

 obtained. He thinks that the presence of impurities in 

 the water used in diluting the sol for ultramicroscopic 

 observations is the cause of this irregularity. In his case 

 ■the m iximuin time covered by the experiments is 80 sees. 

 Similarly, Westgren and Reitstotter, working with coarse 

 gold sols, find the following range of variation in the 

 constant : — 



Table VIII, (6). 

 (Observers : Westgren and Reitstotter.) 

 Ra 







Values of — 



-* 







Series I. 



Series II. 



Series III. 



Series IV. 





3-74 



2-56 



2-75 



3-41 





2-47 



2-81 



2-60 



2-80 





2-07 



2-33 



2-17 



2-60 





2-10 



2-31 



2-40 



2-48 





2-09 



2-31 



212 



2-14 





1-62 



— 



— 



— 





1-41 



2-16 



215 



215 





— 



2'19 



— 



205 



Average 



. 2-2 



2-38 



2-36 



2-19 



Extreme variation., 



.. 75% 



10% 



17% 



55% 



