IMMUNITY REACTIONS 205 



the electrolyte, which itself is not adsorbed, agglutinates or flocks 

 them out. 1 It is therefore obvious that an electrolyte which changes 

 the cells may, nevertheless, without being adsorbed, agglutinate them. 

 According to J. DUNIN-BORKOWSKI*, red blood corpuscles are agglu- 

 tinated by FeCJs, though it is not combined with them. 



Electric Charge, H and OH Ions. 



Numerous attempts have been made to determine the electric 

 charge of antigens and immune substances by cataphoresis (K. 

 LANDSTEINER and Wo. PAULI*, C. N. FIELD and O. TEAGUE*. It is 

 so small, however, that in my opinion it cannot be definitely rec- 

 ognized since traces of H or OH ions may cause a reversal of charge 



(see BECHHOLD* 10 ). 



This also applies to the results of exhaustive adsorption experiments 

 with adsorbents of opposite electric charge, namely, the experiments 

 carried out by EDGAR ZUNZ with electro-osmotically purified silicic 

 acid, aluminium hydroxid, kaolin, diatomaceous earth, talc, and clay 

 upon toxins and antitoxins. With K. LANDSTEINER and W. PAULI it 

 is well to regard antigens and antibodies as amphoteric electrolytes. 



The difference between bacteria and bacteria bearing agglutinin 

 is clearly demonstrated (H. BECHHOLD* 1 , M. NEISSER and U. FRIEDE- 

 MANN*). Though the former (typhoid, dysentery) migrate to the 

 anode, the latter lose their charge on account of the agglutinin and 

 precipitate between the electrodes. 



More characteristic than electrical migration is the behavior of 

 toxins, antigens and immune bodies to acids and alkalis. 2 From 

 our standpoint, only very weak dilutions of H and OH are considered 

 from such as cause no irreversible destruction in the substances 

 affected. Acidity diminishes the toxicity of some toxins, but it is 

 restored by neutralizing them. KIRSCHBAUM isolated a nontoxic 

 dysentery toxin by ultrafiltration and precipitation with acids; it 

 dissolved in alkalis and forms a toxic salt-like combination. An 

 observation made by J. MORGENROTH * 2 points to the occurrence of a 

 salt-like combination of cobra hemolysin and also of cobra neuro- 

 toxin; these neutral toxins, although colloids, diffuse through an 

 animal membrane into a solution containing hydrochloric acid. 

 Cobra venom may be recovered from crystalloid cobra venom salt 

 by neutralizing it, yet it gradually goes into the colloidal state as I 



1 P. SCHMIDT assumes an additional phase; modification of the bacteria by 

 agglutinin, adsorption of globulin by modified bacteria, flocculation by elec- 

 trolytes. 



2 Only great dilutions of H and OH are here considered, such as do not 

 cause an irreversible change in the material. 



