CHAPTER XVI 



TETANUS 



Tetanus is caused by a bacillus which was first ob- 

 tained in pure culture by Kitasato in 1889, five years 

 after Nicolaier had succeeded in producing tetanus in 

 laboratory animals by inoculating them with garden 

 earth. In spite of the relatively frequent occurrence 

 of the bacillus of tetanus in street dust, garden earth, 

 manure, etc., tetanus is a rather rare disease. This is 

 due to the fact that certain conditions must be present 

 before the germ can do its deadly work. Thus, inocula- 

 tion with a pure culture rarely produces the disease, but 

 if other bacteria and dirt are introduced into the wound 

 at the same time the bacillus can elaborate its toxin. 

 An open wound is not nearly so favorable for its de- 

 velopment as a small deep puncture or laceration; the 

 type of wound which most frequently leads to tetanus is 

 that made by a Fourth-of-July toy pistol. The bacillus 

 of tetanus does not grow in the presence of oxygen, 

 i. e., it is an anaerobe, and is usually cultivated in the 

 laboratory in an atmosphere of hydrogen gas, or in air 

 from which oxygen has been abstracted. If this condi- 

 tion is fulfilled, it grows quite well on the ordinary cul- 

 ture-media, producing gas and a very disagreeable odor. 



Grown under favorable conditions, the bacillus is a 

 slender rod, of medium length, which is not decolorized 

 by Gram's stain, i. e., it is ''Gram-positive." It is able 

 to travel across the microscopic field, owing to the pres- 



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