85 



terisiert sein, class sie sich prinzipiell von den Tropfchen der mikro- 

 skopischen Emulsionen unterscheiden". 



It was a long time before BEIJERINCK'S observations found the 

 appreciation in colloid chemistry which they merited, but in later 

 years this appreciation was shown. In 1911 TIEBACKX l ) described 

 a new example of the phenomenon as observed by BEIJERINCK; in 

 1927 Wo. OSTWALD and KOHLER 2) devoted a study to another 

 instance, and in 1929 BUNGENBERG DE JONG and KRUYT 3 ) added a 

 number of cases, and gave the name of coacervation to the phe- 

 nomenon. Since then it has become of increasing importance in 

 colloid chemistry. 



If one examines the present conception as to the nature of "co- 

 acervation" (see, for instance, the figure on page 202 of H. R. KRUYT 

 andH. S. VAN KLOOSTER "Colloids" 4 )), it will be apparent that BEIJE- 

 RINCK'S conception of a difference between colloidal particles and 

 suspended droplets has been justified. 



!) F. W. TIEBACKX, Gleichzeitige Ausflockung zweier Kolloide, Kolloid-Zeitschrift 

 8, 198-201, 1911. 



2 ) Wo. OSTWALD und R. KOHLER, Uber die fliissig-fliissige Entmischung von 

 Gelatine durch Sulfosalizylsaure und iiber die Beziehungen dieses Systems zur Pha- 

 senregel, Kolloid-Zeitschrift 43, 131-150, 1927. 



3 ) H. G. BUNGENBERG DE JONG and H. R. KRUYT, Coacervation (Partial misci- 

 bility in colloid systems), Proceedings of the Section of Sciences, Kon. Akad. v. We- 

 tenschappen Amsterdam 32, 849-856, 1929. 



") Second Edition, New York 1930. 



