IMMUNITY AGAINST TETANUS. 391 



protect 100,000,000 grammes' weight of mice. 1 The potency 

 is maintained for several months if precautions are taken to 

 avoid putrefaction, exposure to bright light, etc. To this end 

 .5 per cent carbolic acid is usually added, and the serum is 

 kept in the dark. In a case of tetanus in man, 100 c.c. 

 of such a serum should be injected within twenty-four hours 

 in five doses, each at a different part of the body, and 

 this followed up by further injections if no improvement takes 

 place. It is stated that better results have been obtained 

 when the fluid serum has been injected intravenously, and that 

 large amounts can be safely employed. Of this method we 

 have had no experience. The serum has also been introduced 

 intracerebrally, 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 

 with only a small measure of success. 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, un- 

 doubtedly, from time to time cases of tetanus would be detected 

 early, and their treatment could be undertaken with more hope 

 of success than at present. However, in the existing state of 



1 The antitetanic serum sent out by the Pasteur Institute in Paris has a strength 

 of 1-1,000,000,000. Of this it is recommended that 50 to 100 c.c. should be injected 

 in one or two doses. 



