522 BACTERIOLOGY. 



lished, the circulating blood contains a body, antitoxin, 

 that combines directly with tetanus toxin in a test-tube, 

 and thereby renders it physiologically inactive (non-in- 

 toxicating) ; and the serum of the immune animal is 

 not only capable of protecting non-immune, susceptible 

 animals from the poisonous action of tetanus toxin 

 (within limits), but also against the eifects of the living 

 tetanus bacillus as well. 



Tetanus antitoxin, though the first antitoxin discov- 

 ered and frequently employed in the treatment of 

 tetanus, has not yielded as brilliant results as those 

 obtained with diphtheria antitoxin. There are good 

 reasons why tetanus antitoxin may never be expected to 

 yield such satisfactory results as does diphtheria anti- 

 toxin. Diphtheria infection can be recognized by bac- 

 teriological methods and the antitoxin administered long 

 before very marked constitutional symptoms have devel- 

 oped, and consequently long before the diphtheria toxin 

 has had time to bring about serious tissue alterations. 

 In tetanus it is impossible to make such a definite bac- 

 teriological examination, and very frequently the first 

 suggestion of the disease is the twitching of the muscles, 

 the antecedent sign of the tetanic convulsions. \Vheii 

 these clinical manifestations have developed in tetanus 

 there is already very serious involvement of the centra- 

 nervous system. 



In the use of tetanus antitoxin it is advisable to 

 employ it as early as possible and to give repeated doses 

 until the symptoms are relieved. Whether the subdural 

 administration of the antitoxin will be of greater value 

 than the subcutaneous administration is as yet unsolved. 



A great deal of benefit is also likely to result from 

 the administration of tetanus antitoxin as a prophy- 



