374 



Prof. A. J. Brown and Mr. F. Tinker. 



Table I. — Seeds in Aniline Solutions of Various Strengths. 

 Temperature 15° C. 













Ratio of 



Strength, of aniline 

 solution outside 

 seeds. 



Lxain in 



"Wpltrllt", CiT 



5 grm. seeds 



VV cl&Ilu UL 



found, inside 

 seeds. 



w eigut 



of wfi tpi* 



inside 

 seeds. 



Strength of 

 solution inside 

 seeds. 



strength 

 solution 

 inside 

 to strength 

 solution 

 outside. 





grm. 



grm. 



grm. 







N/4 (2-30 grm. per 



2-724 



0-184 



2 -540 



7 '25 grm. per 



3-15 



100 grm. water) 









100 grm. water 





N/8 (1 -16 grm. per 



2-564 



0-087 



2 -447 



3 -52 grm. per 



3 -04 



100 grm. water) 









100 grm. water 





N/12 (0-87 grm. per 



2 -909 



0-067 



2-842 



2 "35 grm. per 



2-70 



100 grm. water) 

 N/16 (0 -575 grm. per 









100 grm. water 





2 -851 



-042 



2 -849 



1 '47 grm. per 



2-55 



100 grm. water) 









100 grm. water 





In each instance the aniline solution is stronger within the seed than in 

 the outside solution. Moreover, the aniline solution inside the seeds 

 becomes stronger as the outside solution becomes stronger, and is in each of 

 the experiments about three times as strong as the latter. Further, it will 

 be noticed that the solution diffusing into the seeds from N/4 aniline 

 solution contains more aniline than does a saturated solution, i.e., the 

 adsorbed solution is highly supersaturated.* 



(b) Phenol Solutions. — The procedure was exactly the same as in the case 

 of aniline, the phenol being estimated as tribromphenol.f The results are 

 given in Table II. 



Manifestly concentration of phenol within the seeds takes place as in 

 the case of aniline. The high degree of supersaturation of the solution 

 adsorbed from the IST/2 phenol is also very marked. 



(c) Acetic Acid Solutions. — Acetic acid, unlike aniline and phenol, is 

 miscible with water in all proportions, so that solutions of any chosen con- 

 centrations from to 100 per cent, acetic acid can be employed. 



To determine the concentration of the adsorbed solution within the seeds, 

 the latter were hydrolysed with a known volume of standard sulphuric acid, 

 the solution filtered, made up to a known volume (250 Co.), and titrated with 

 standard NaOH, correction being made for the sulphuric acid employed 



* This fact possibly indicates that the solubility of the aniline is increased in the 

 adsorbed film in contact with colloidal surfaces. 



t A. small correction had to be made for the solubility of the tribromphenol in water. 

 When this was done the accuracy of the results was about the same as for aniline 

 (3 or 4 per cent.). 



