136 



a heliotropin solution e.g. tliat i-emained free from submicroiis, even 

 after standing for niontlis, thej appear in a rather large number 

 direcdy after the old solution was shaken for some time in the closed 

 cuvette. The same occurs with gljcerinous solutions. Eugenol poured 

 on glycerin without shaking renders the latter non-opalescent in 

 five days. When it is vigorously shaken, however, the fluid is rendered 

 slightly opalescent, and colloidal in the real sense of the word. It 

 also retains its suspensoidal character in the subsequent phase of 

 the process. 



It is not likely that chemical energy should also come into play, 

 since the process also takes place in chemically all but inditrerent 

 fluids, such as paraffin, though it must also be added that entire 

 deoxidation of paraffin inhibits transformation also in ultraviolet light. 

 However, there must be still another unknown source of energy, 

 apart fiom the radiation of light and the mechanical energy, 

 which supplies the newly generated micellae with surface-energy, 

 with or without the aid of oxygen, since eugenol solution enclosed 

 in a leaden casket, kept in utter darkness, becomes undoubtedly 



Transformation to a colloidal state of aqueous solutions in the Anilin-series. 



Molec. weight 



Number of Atoms 



Tyndall's effect 



Anilin . . . 

 Toluidin. 

 Xylidin . . 

 Cumidin. 



93 



107 

 121 

 135 



14 



n 



20 

 23 



hardly distinguishable 

 rather distinct 



n » 



distinct 



Id. In the Benzolseries. 



suspensoidal within a few days. However, to obtain this, large 

 dissolved molecules are required. This is clearly shown when 

 comparing the terms of an homologous series inter se. 



