440 PROTEIN POISONS 



non-fatal doses. Diphtheria antitoxin protects only against 

 diphtheria toxin, and not against that of the tetanus or 

 dysentery bacillus, or that of snake venom. 



The side-chain theory evolved by the genius of Ehrlich 

 best explains the action of toxins and the production of 

 antitoxins. Without subscribing to all the details of this 

 theory, we believe that it is a biological law that when a 

 living cell is attacked by a destructive ferment or toxin it 

 tends to elaborate an antiferment or antibody. This is 

 one of the ways in which the living cell may protect itself. 

 The formation of such antibodies in multicellular animals 

 is one of the factors in the fine adjustment essential to 

 harmony of action between different tissues and organs. 

 It best explains the fact that the digestive organs do not 

 harm themselves, and the antitryptic action of blood-serum 

 is one of the most interesting and important phases of 

 parenteral digestion. 



The number of pathogenic bacteria which produce 

 toxins, at least in appreciable quantity, is small, and the 

 action of toxins and antitoxins in infections due to those 

 organisms which do not produce such bodies is of minor 

 importance. Since all bacteria, and in fact all living cells 

 produce ferments, and since every ferment, so far as we 

 know, may lead cells acted upon by them to produce anti- 

 ferments, there may be some toxin and antitoxin action 

 in all infections, but in most bacterial infections such 

 action is overshadowed by processes much more powerful 

 in their effects. 



In our opinion the action of the diphtheria bacillus may 

 be stated as follows: The organism finds lodgement and 

 the conditions for growth favorable in the upper air pas- 

 sages. Here it grows in mass and may kill by mechanical 

 obstruction. It produces its soluble, diffusible toxin, 

 which has the properties of a ferment and splits up the 

 proteins of the body, setting free the protein poison. In 

 case of recovery or in the production of antitoxin in animals, 

 the body cells elaborate an antiferment or antitoxin which 

 neutralizes the toxin and prevents its cleavage action. 



