TETANUS. 293 



Chantemesse and Widal at one time thought that the pre- 

 sence of other organisms was necessary in order that the 

 tetanus bacillus might act, and it has been suggested that 

 aerobic organisms which have great avidity for free oxygen 

 must also be present in order to allow of the development 

 of the full virulence of the anaerobic tetanus bacillus. It is 

 a fact, whatever may be the explanation, that the tetanic 

 organism soon loses its virulence under cultivation, especially 

 when it is grown " pure." 



Recently, however, Vaillard and Vincent, as the result 

 of a series of most careful observations, have arrived at the 

 conclusion that it is usually the tetanus poison which 

 they compare to snake poison and not the organism 

 itself that gives rise to the tetanic symptoms in animals 

 that are infected experimentally. They also find that until 

 the organism has grown in artificial culture media for 

 some time it has not the power of setting up disease, a 

 fact that was accounted for when they found that no poison 

 was developed until some time after the organism had begun 

 to grow, the production of the poison appearing to go on 

 simultaneously with the formation of a peptonizing enzyme. 

 Even spores, when injected alone, could not set up tetanic 

 symptoms, but when these were injected along with other 

 organisms such as lactic acid bacillus, or even with lactic acid 

 itself, with bacillus prodigiosus, or into a bruised wound, or 

 where they were injected along with a quantity of their 

 own poison, tetanus was invariably set up. The tetanus 

 organisms form their poison slowly, and in healthy tissues 

 they are rapidly destroyed by the tissue cells long before 

 they have time to form sufficient poison to produce the 

 nervous symptoms of tetanus ; whilst in the cases above 

 mentioned the tissue cells are so engaged in removing the 

 other foreign matter, or are so paralyzed by the action of 

 the lactic acid, or the small portions of tetanus poison, that 

 they are not able to contend on equal terms with the tetanus 

 bacilli, which being under favourable conditions grow rapidly, 

 give rise to the formation of the special poison, and the 

 patient succumbs. This remarkable poison in doses of 25 

 millegrammes is quite sufficient to kill a rabbit, or the 25th 

 of a millegramme to kill a mouse. 



The tetanus bacillus is a facultative saprophyte, the nature 

 of the wounds through which tetanus is inoculated bearing 



