ASPECTS OF ADSORPTION PHENOMENA 229 



20. The different behaviour of silk and paper towards electro- 

 negative and electro-positive dyes, as also the influence of alcohol on 

 the process, is to be explained by the results of Coehn on the influence 

 of the respective dielectric constants on the charge. 



21. When gelatin is precipitated by tannin its adsorbed electro- 

 lytes are split off. 



22. There is no evidence of a sudden separation of electrolytes 

 at the moment of death. There is a gradual one when a living tissue 

 is warmed from 1 1 C. to 56 C. 



23. In the process of clotting of blood there is a diminution ot 

 electrical conductivity, so that ions (probably c++) disappear from 

 solution. 



24. The adsorption affinity of gelatin for acid-fuchsin is greater 

 than that for congo-red, while that of paper is the same for both. 



25. A theory of dyeing is suggested on the basis of adsorption 

 in relation to electrically-charged colloids. 



26. An explanation, apart from different permeability of the cell, 

 is suggested for the staining of living cells by basic dyes and the non- 

 staining by acid dyes. 



27. The nature of the compounds between acid and basic dyes is 

 investigated. They appear to be uncharged colloids, but the evidence 

 as to whether they are colloidal adsorption compounds or true chemical 

 compounds is not decisive. 



28. Evidence is brought forward to show that the union between 

 enzyme and (colloidal) substrate is of the nature of adsorption. The 

 adsorption of trypsin by paper is facilitated by calcium sulphate. 



