428 TETANUS 



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 

 vegetative 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 oedema, which also is of common 

 occurrence in the soil {vide infra).] 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 an attempt 

 was made with regard to tetanus to explain the general symptoms by 

 the soluble poisons of the* bacillus. 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 

 tmcalbumin from tetanus cultures, and this body was independently 

 discovered by Faber in the same year. Brieger and Fraenkel's body 

 consisted practically of an alcoholic precipitate from filtered cultures 

 in bouillon, and was undoubtedly toxic. Within recent years such 

 attempts to isolate tetanus toxins in a pure condition have practically 

 been abandoned, and attention has been turned to the investigation 

 of the physiological effects either of the crude toxin present s in 

 filtered ordinary bouillon cultures grown under anaerobic conditions, 

 or of the precipitate produced from the same by ammonium sulphate 

 (cf. p. 190). 



The toxic properties of bacterium-free filtrates of pure 

 cultures of the b. tetani were investigated in 1891 by Kitasato._ 

 This observer found that when the filtrate, in certain doses, was 

 injected subcutaneously or intravenously into mice, tetanic spasms 

 developed, first in muscles contiguous to the site of inoculation, 

 and later all over the body. Death resulted. He found that 

 guinea-pigs were more susceptible than mice, and rabbits less so. 

 In order that a strongly toxic bouillon be produced, it must 



