TETANUS ANTI-TOXIN. 107 



tin.- same throughout the United States the Hygienic Laboratory 

 of the United States Public Health and Marine Hospital Service 

 sends out at regular intervals a stable precipitated tetanus toxin 

 \vliich is called the "test dose" and contains one hundred times 

 the smallest fatal dose. It will be observed that a unit of 

 tetanus anti-toxin contains more than ten times as much neu- 

 tralizing value as does a unit of diphtheria anti-toxin. The var- 

 ious anti-tetanic serum producers furnish their product in suitable 

 syringes, and, as is the case with diphtheria anti-toxin, state the 

 date after which it is desirable that.the serum be returned if not 

 used. 



The value of tetanus anti-toxin and the methods for adminis- 

 tration can only be judged after study of the action of the tetanus 

 bacillus and its toxin. Tetanus in man is usually the result of 

 the subcutaneous introduction of tetanus bacilli, some foreign 

 matter and usually saprophytic organisms. Thus the disease 

 follows most frequently upon puncture and contused wounds 

 as the result of injuries made by machinery, pistol shots, trauma- 

 tism especially in stablemen, infection of the naval during or 

 after birth, and sometimes as a result of the injection of con- 

 taminated vaccines and sera. The distribution of the organism 

 is very wide, being found practically everywhere where there is 

 animal habitation. 



After the entrance of the tetanus bacillus, usually there is 

 little change produced in the tissues infected. Suppuration occurs 

 practically only as a result of other organisms. Usually the or- 

 ganisms remain localized. The disease and its symptoms are 

 entirely dependent on the absorption of the toxins produced by 

 the tetanus bacilli. Tetanus toxin circulates in the blood and 

 lymph, but shows no symptoms until it unites with and is ab- 

 sorbed by the end organs of the motor nerves and the central 

 nervous system. To reach the end organs the toxin is^Mwried 

 through the axis cylinders. It is thus seen that when the symp- 

 toms of the disease appear, the toxins have already combined with 

 the cells, are exerting their toxic effects on them and can no longer 

 combine with the anti -toxin which is not taken up by the central 

 nervous system. In cases not treated with tetanus anti-toxin, Rose 

 has found that ninety-one per cent of the cases in which the incuba- 

 tion period is short, terminate fatally; 81.3 per cent of those 



