Chemisches. — Methoden. 159 



resembling the condensation products described above, prepared by 

 laborator}^ methods. This substance yielded diphenylmethane when 

 reduced, probably the condensation products of formaldehyde with 

 tannic and oxybenzoic acids are formed in the plant and precipitated 

 at an early stage in the cell walls of the cork. 



In Fiichsia the cork consists of small and large cells alternating 

 radiall)^ Only in the smaller cells could' gallic acid be demonstrated. 

 For the condensation products described the name phellemic 

 acid is suggested. E. Drabble (Liverpool.) 



Hedin, G. S., A case of specific Adsorption of Enzymes. 

 (Biochemical Journal II. W. 3. p. 112—116. 3. July. 1907.) 



Adsorption of enzymes may be to a large degree specific. The 

 kieselguhr used in extracting enzymes may adsorb some enzymes 

 in large quantity, while others are but slightly adsorbed, or even 

 entirely untouched. Hence juices prepared with kieselguhr, as pro- 

 posed b}" Bu ebner in the case of yeast, do not necessarily contain 

 the enzymes in the same proportion as the cells used. The enzymes 

 might be adsorbed by the kieselguhr, or perhaps by the solid 

 remains of the cells, and consequently, some of them might be comple- 

 tely retained in the press-cake. E. Drabble (Liverpool). 



Hedin, G. S., On extraction b}^ Casein of Trypsin, adsorbed 

 by Charcoal. (Biochemical Journal. IL N«. 3. p. 81—81. July 

 1907.) 



The results support the view that proteins combine with trj'psin 

 before they are broken up by the same as previously shown by 

 the author. Charcoal can adsorb trypsin in the Solution. He now 

 shows that both charcoal and casein take up trypsin in some pro- 

 portion to the amount of substances present and therefore the final 

 distribution of trypsin will be the effect of some kind of mass action. 

 But this mass action cannot completely obey Guldberg-Waage's 

 law for Solutions since in real Solutions the final equilibrium will be 

 the same independently of the way in which it has been arrived at. 

 In the case of charcoal and trypsin on the contrary the trypsin 

 becomes fixed to the charcoal by degrees and only a small portion 

 can be extracted by added casein, less being extracted the longer 

 the time and the higher the temperature for the interaction of 

 charcoal and trypsin before the casein is added. The final distribu- 

 tion of the trypsin, therefore, depends ver\' much upon the way 

 in which it has been arrived at. E. Drabble (Liverpool). 



Kayser, H., Eine Fixierungsmethode für die Darstellung 

 von Bakterienkapseln. (Centn f. Bakt. 1 Abt. Originale. Bd. XLI. 

 38/40. 1906.) 



Verf. empfiehlt die von Weidenreich angegebene Art der Fixie- 

 rung von histologischen Praeparaten auch als Fixierungsmethode für 

 die Darstellung von Bakterienkapseln. Die Anwendung dieses Verfah- 

 rens ist folgendes: 2 Lösungen werden bereitet. I. In 5 ccm. I^'/q Osmium- 

 säurelösung kommen 10 Tropfen Eisessig. IL Eine sehr dünne wäs- 

 serige Lösung von Kaliumpermanganat. Die Objektgläschen werden 

 mindestens 2—3 Minuten vor dem Aufbringen des Materials den Osmi- 



