TOXINS OF THE TETANUS BACILLUS 423 



day, and death occurs in two or three days, after inoculation 

 with a loopful of a bouillon culture. The other animals 

 mentioned require larger doses, and death does not occur so 

 rapidly. Usually in animals injected subcutaneously the spasms 

 begin in the limb nearest the point of inoculation. In the 

 case of intravenous inoculation the spasms begin in the 

 extensor muscles of the trunk, as in the natural disease in man. 

 After death there is found slight hypenemia without pus forma- 

 tion, at the seat of inoculation. The bacilli diminish in number, 

 and may be absent at the time of death. The organs generally 

 slio\\ little change. 



Kitasato stated that in his earlier experiments the quantity of 

 culture medium injected along with the bacilli already contained 

 enough of the poisonous bodies formed by the bacilli to cause 

 death. The symptoms came on sooner than by the improved 

 method mentioned below, and were, therefore, due to the toxins 

 already present. In his subsequent work, therefore, he employed 

 splinters of wood soaked in cultures in which spores were 

 present, and subsequently subjected for one hour to a tempera- 

 ture of 80" C. The latter treatment not only killed all the 

 Yegetative forms of the organism, but, as we shall see, was 

 sufficient to destroy the activity of the toxins. When such 

 splinters are introduced subcutaneously, death results by the 

 development of the spores which they carry. In this way he 

 completed the proof that the bacilli by themselves can form 

 toxins in the body and produce the disease. Further, if a 

 small quantity of garden earth be placed under the skin of a 

 mouse, death from tetanus takes place in a great many cases. 

 [Sometimes, however, in such circumstances death occurs with- 

 out tetanic symptoms, and is not due to the tetanus bacillus but 

 to the bacillus of malignant cedema, which also is of common 

 occurrence in the soil (vide infrd)J\ By such experiments, 

 supplemented by the culture experiments mentioned, the natural 

 habitats of the b. tetani, as given above, have become known. 



The Toxins of the Tetanus Bacillus. The tetanus bacillus 

 being thus accepted as the cause of the disease, we have to 

 consider how it produces its pathogenic effects. 



Almost contemporaneously with the work on diphtheria was the 

 attempt made with regard to tetanus to explain the general symptoms 

 by supposing that the bacillus could excrete soluble poisons. The 

 earlier results, in which certain bases, tetanin and tetanotoxin, were 

 said to have been isolated, have only a historic interest, as they were 

 obtained by faulty methods. In 1890, Brieger and Fraenkel announced 

 that they had isolated a toxalbumin from tetanus cultures, and this body 

 \\;is independently discovered by Faber in the same year. Brieger and 



