IMMUNITY AGAINST TETANUS 387 



that v both intravenous and subcutaneous injections should be 

 simultaneously practised. The former gives the quickly attained 

 concentration which is desirable, and when the antitoxin injected 

 intravenously is beginning to be eliminated that introduced 

 hypodermically comes into the circulation and the concentration 

 is maintained. The antitoxin has also been introduced intra- 

 cerebrally, very slow injection into the brain substance being 

 practised, but no better results have been obtained than by the 

 subcutaneous method. 



Many cases of human tetanus have been thus treated, but 

 the improvement in the death-rate has not been nearly so 

 marked as that which has occurred in diphtheria under similar 

 circumstances. As in the case of diphtheria, however, the 

 results would probably be better if more attention were paid 

 to the dosage of the serum. The great difficulty is that, as a 

 matter of fact, we have not the opportunity of recognising the 

 presence of the tetanus bacilli till they have begun to manifest 

 their gravest effects. In diphtheria we have a well-marked 

 clinical feature which draws attention to the probable presence 

 of the bacilli a presence which can be readily proved, and 

 the curative agent can thus be early applied. In tetanus the 

 wound in which the bacilli exist may be, as we have seen, of 

 the most trifling character, and even when a well-marked 

 wound exists, the search for the bacilli may be a matter of 

 difficulty. Still it might be well, when practicable, that every 

 ragged, unhealthy-looking wound, especially when contaminated 

 with soil, should, as a matter of routine, be examined 

 bacteriologically. In such cases, undoubtedly, from time to 

 time cases of tetanus would be detected early, and their treat- 

 ment could be undertaken with more hope of success than at 

 present. However, in the existing state of matters, whenever 

 the first symptoms of tetanus appear, large doses, such as those 

 above indicated, of a serum whose strength is known, should be 

 at once administered. In giving a prognosis as to the probable 

 result, the two clinical observations on which, according to 

 Behring, chief reliance ought to be placed, are the presence or 

 absence of interference with respiration, and the rapidity with 

 which the groups of muscles usually affected are attacked. If 

 dyspnoea or irregularity in respiration comes on soon, and if group 

 after group of muscles is quickly involved, then the outlook is 

 extremely grave. In addition to these points the duration of the 

 incubation period is of high importance in forming a prognosis. 

 The shorter the time between the infliction of a wound and the 

 appearance of symptoms the graver is the outlook. 



