46 APPLIED IMMUNOLOGY 



this method when compared with cases treated by anti- 

 septic sprays alone, and many cases of " carriers " 

 that have resisted all other forms of treatment have 

 responded rapidly to it. 



Antitetanic Serum 



Tetanus, like diphtheria, is a disease, manifesta- 

 tions of which depend upon a toxin separated from 

 the tetanus bacilli in the process of growth. When 

 a wound becomes infected with tetanus bacilli, the lat- 

 ter remain at the point of entrance and give off the 

 toxin which is disseminated along the nerve sheaths 

 mitil it reaches the spinal cord. Here the toxin com- 

 bines with the cells of the central nervous system, and 

 gives rise to the typical s}Tnptoms of the disease. This 

 affinity of tetanus toxin for nerve tissue has an im- 

 portant bearing in the treatment of tetanus. 



The method of artificially producing antitetanic 

 serimi is similar to that of producing antidiphtheric 

 serum. Tetanus toxin is formed by growing tetanus 

 bacilli anaerobically in bouillon for several dsLjs, the 

 bacilli being then removed by passing the fluid through 

 a Berkefeld filter. The filtrate is now injected into a 

 horse, at first in small amounts (0.5 c.c.) mixed with 

 a quantity of antitetanic serum. The doses are then 

 gradually increased, the antitoxin being omitted after 

 the first few injections. There are several methods of 



