46 



HEALTH AND DISEASE 



the abscess which was formed at the point of inoculation several micro- 

 organisms were found, arid one of them produced similar tetanic symptoms 

 when inoculated into other animals. 



Some considerable time elapsed before what is now known as the 

 tetanus bacillus was obtained in the state of pure cultivation, owing to 

 the fact that the microbe was anaerobic, and consequently would not grow 

 in the air. Pure oxygen, it is said, destroys it completely. The bacillus 

 occurs in the form of small motile rods 



with the spore at one end, giving to the 



organism 



Fig. 219, Bacillus tetani 



to 



the appearance of a minute 

 drum -stick, and it grows readily on the 

 usual media when kept in an atmosphere 

 of hydrogen. Dr. Sims AVoodhead, in his 

 work on Bacteria and their Product, 

 remarks, in reference to the universal 

 distribution of the bacillus, that M. Bos- 

 sano obtained soil from forty-three dif- 

 ferent regions in various parts of the 

 globe, and produced tetanus in white 

 mice and guinea-pigs with twenty -seven 



out of the forty-three specimens, and from his experiment Bossano con- 

 cluded that soils which contain much organic matter almost invariably 

 contain tetanus bacilli. 



The information which has been obtained of late years proves that 

 tetanus is one of the pure contagia, and is due to the introduction of the 

 specific microbe into the animal system through a wound in some part 

 of the exterior of the body. Whether or not it is possible that the disease 

 may arise from the introduction of contaminated soil into a wound in 

 any part of the alimentary canal it is impossible to determine. There do 

 not, however, appear to be any facts which would militate against this 

 assumption, and infection occurring in this way that is, through the 

 agency of a wound in the interior of the body would naturally give rise 

 to the idea that the disease was idiopathic in its origin. There can be 

 no doubt, however, that the majority of cases are due to the infliction of a 

 wound on the exterior of the body, especially in such a position that the 

 injured part is likely to come frequently in contact with the earth. 



It appears that on entering the wound the bacillus of tetanus locates 

 itself in the damaged tissues, and is not distributed throughout the body. 

 The poison, however, which it produces in the wound during its growth 

 will be readily absorbed and carried to the nerve centres, inducing the irri- 

 tation which results in the tetanic spasm of the muscles. 



