234 BACILLUS OF TETANUS. 



serum, must be used. Enough serum must be injected to 

 neutralize the toxin in the body. 



The toxin is prepared from active bouillon cultures, which 

 are filtered through porcelain. It is preserved by the addi- 

 tion of 0.5 per cent, of carbolic acid. 



The antitoxin is prepared by inoculating horses with gradu- 

 ally increasing doses of the toxin until the desired degree of 

 immunity is attained. The method of preparation of anti- 

 toxins has been described in a preceding chapter. The same 

 product is used for immunization and for therapeutic pur- 

 poses. 



This serum has yielded remarkably good results as an 

 immunizing agent; but not as a therapeutic measure. The 

 reason for this is evident when we remember that unfortu- 

 nately cases of tetanus do not present themselves for treat- 

 ment as soon as the injury has occurred. The patient is not 

 seen until he presents the active manifestations of the disease, 

 and then it is impossible to administer enough antitoxin to 

 neutralize all the toxin which is already in circulation. Per- 

 sons should present themselves for treatment as soon as the 

 injury has occurred, so that prompt measures may be taken to 

 prevent development of the disease. The antitoxin must be 

 used early and in sufficient quantity to be of any service as a 

 curative agent. 



Roux and others have suggested that the antitoxin be 

 injected under the dura mater through a trephine-opening. 

 It is believed that if the antitoxin is brought into direct con- 

 tact with the cerebral substance a cure is more apt to result. 

 Most authorities recommend making the injection directly 

 into a vein, so as to insure prompt action. When injected 

 subcutaneously, the antitoxin must be absorbed first and thus 

 the action is delayed. 



Wassermann is of the opinion that it is possible to obtain 

 an immunizing substance from the nerve-cells of the cord and 

 brain of cases of tetanus. He removed the brain and cord 

 from tetanized animals and rubbed them up with physiologic 

 salt solution. This mixture was injected into animals, and 

 Wassermann found that in doses of 1 c.c. it neutralized ten 

 times the amount of tetanus toxin necessary to kill an animal, 



