214 A MANUAL OF BACTERIOLOGY 



As the tetanus bacillus is localised, there can be 

 no doubt that tetanus is due to the above poisons 

 (manufactured indirectly by the bacillus) producing 

 effects after getting into the blood, by virtue of 

 some selective action on certain parts of the motor 

 nerve-centres. 



The spores of the tetanus bacillus have an ex- 

 tremely wide distribution, being found in soils, etc., 

 in various parts of the world. According to Bos- 

 sano, 1 soils which contain much organic matter 

 nearly always contain tetanus bacilli, ' and that 

 latitude, climate, and special meteorological condi- 

 tions have far less influence on their development 

 than defective drainage, imperfect hygienic condi- 

 tions, and the degree of cultivation of the soil.' 



Dr. Kitasato 2 has recently shown how to produce 

 immunity against tetanus, and he has cured animals 

 suffering from this disease. Kitasato first renders 

 an animal immune against tetanus, and then injects 

 the blood serum of that animal into animals suffering 

 from the disease. In order to render an animal 

 immune or unsusceptible, the tetanus bacilli are 

 first injected ; this injection being followed by in- 

 jections of iodine trichloride, which are repeated at 

 intervals of twelve hours. After four days the 

 animal, which under ordinary circumstances would 

 have died from tetanus, is not only cured, but ren- 

 dered immune against the disease. The blood serum 

 of such an animal has been found in successive 



1 Comptes Rendus, tome 107, p. 1172; and Recherches Ex- 

 pdrimentales sur VOrigine Microbienne du Tetanos (1890). 



2 Deutsche Medicinische Wochenschrift, 1890, No. 49, et seq. 



