﻿3 1 2 Profs. J. N. Mukherjee and B. C. Papacon stun tin ou on 



distribution of the particles n 1? n 2 , etc. will produce a 

 great change in the optical properties of the sol. This 

 is in agreement with observations. Now, if the successive 

 stages of coalescence were independent of the nature and 

 concentration of the electrolyte, then the manner of 

 variation of the complex absorption would be the same 

 in each case. The absorption in the red region of the 

 spectrum varies continuously, corresponding to each value 

 of the absorption coefficient for a particular wave-length in 

 this region ; the values in the other parts should be fixed. 

 If the contrary holds good, then the conclusion is obvious 

 that the successive stages of coalescence are not inde- 

 pendent of the nature and concentration of the electrolyte 

 as assumed by Smoluchowski. 



It has been found that for the stage indicated by the 

 value of the coefficient of absorption for 683 /£/u = 0*4985, 

 the values of the coefficient for the other wave-lengths 

 given in the following table in column II. are independent 

 of the nature of the electrolyte. 



The concentrations of the electrolytes were such as to 

 produce rapid coagulation. In columns III. and IV. the 

 coefficients of the "nucleus sol" have been given for 

 the original sol and for the stage of coagulation cha- 

 racterized by the value of the coefficient for 683 /xyu, = 0'4156 

 (Mukherjee and Papaconstantinou, loc. cit.). 



Wave-length, 



Table I. 



Absorption coefficients (Jc). 



iafifi. I. II. III. IV. 



683 0-0453 0-4985 0*0376 0-4156 



602 0-1055 0-3679 0-1131 0409 



583 0-1518 0-3388 0-1595 0-3986 



563 0-2076 0-3294 0-2076 0-336 



547 0-2512 3238 0-2867 0-3732 



523 0-3780 0-3780 0-3780 0-3882 



506 0-4647 0-3581 0-3882 0-3780 



475 0-3581 03198 0-3581 03780 



Comparison of the Values of " T " as a Test of 

 Smoluchowski' 's Theory. 



Since the absorption coefficient in the red region varies 

 continuously with the coagulation and its magnitude is 



