CULTIVATION EXPERIMENTS. 143 



by heat was happily followed by a complete cessation of the unde- 

 sirable sequences. 



Although the infectious nature of tetanus was suspected for a 

 long time, it is only quite recently that the real microbic cause was 

 discovered almost simultaneously by Nicolaier and Rosenbach. 

 Nicolaier showed the exogenous origin of the disease by finding a 

 bacillus in earth which produced tetanus in animals by inoculation. 

 Kosenbach found a similar bacillus in the pus of a patient suffering 

 from traumatic tetanus. The identity of the bacillus of tetanus 

 with Nicolaier's bacillus of earth tetanus was demonstrated in 

 Koch's laboratory April 10, 1887. 



DESCRIPTION OF THE BACILLUS TETANI. Rosenbach describes 

 the bacillus as an anaerobic microorganism which presents a bristly 

 appearance, with a spore at one of its extremities which gives it the 

 resemblance to a pin, or drumstick. According to Kitasato, the 



FIG. 



Tetanus bacilli bearing spores from an agar culture. X 1000. 

 (FRANKEL and PFEIFFER.) 



bacilli produce spores in 30 hours in cultures kept at a temperature 

 of the body. They manifest great resistance to heat, as they have 

 been found active after an exposure of one hour to 80 C. (176 F.) 

 moist heat, and are only destroyed by placing them in a steam appa- 

 ratus heated to 100 C. (212 F.) for five minutes. The bacillus has 

 been found in different kinds of soil and in street dust. In man, it 

 has been found in tetanic patients in the wound secretions, in the 

 nerves leading from the seat of infection, and in the spinal cord. 



CULTIVATION EXPERIMENTS. Roseubach found it impossible 

 to obtain a pure cultivation ; although he resorted to fractional 



