TETANUS. 149 



toxins have been destroyed produce no symptoms whatever. 

 These toxins are destroyed by a temperature of 60 to 65 C., 

 by prolonged exposure to diffuse daylight, or by exposure for 

 one hour to direct sunlight, and cultures containing spores 

 so exposed are innocuous to animals. 



The author has succeeded in several instances in obtaining 

 the tetanus bacillus by the following cultivation- method : 



After thoroughly heating a bouillon tube or a liquid gela- 

 tin tube so as to expel as much as possible all the oxygen, 

 the culture is allowed to cool to a temperature a little below 

 80 C. The suspected material is then inoculated deep into 

 the tube, and the surface of the medium is covered by a layer 

 of 1 to 2 c.c. of paraffin oil, a cotton plug inserted, and a 

 rubber cap applied over the tube. 



In this way he has obtained cultures with great facility. In 

 one case, notably, cultures were made from the surface of a 

 nail, that caused a wound which produced tetanus in an adult. 

 In another case a piece of diphtheritic membrane wrapped in a 

 piece of gauze and kept on the hearth over night, was handed 

 to him from a diphtheria patient for examination. The next 

 day to his surprise besides the diphtheria bacilli a few bacilli 

 resembling the tetanus bacilli were found. A piece of this 

 membrane was inoculated into bouillon prepared in the fore- 

 going manner, and he obtained after three or four days a pure 

 culture of the tetanus bacillus which proved fatal to guinea- 

 pigs. 



Pathogenesis. The animals susceptible to the Bacillus tetani 

 are man, horses, guinea-pigs, rabbits, and mice. Dogs are 

 little susceptible, and birds scarcely at all. Amphibians can 

 not be infected. The inoculation of animals is made by means 

 of a liquid culture injected subcutaneously or by means of 

 some of the contaminated material introduced into a deep 

 pocket in the subcutaneous tissue. The period of incubation 

 is more or less prolonged, varying from a few days to occasion- 

 ally two or three weeks. During this time the bacilli seem to 

 be generating their poison. After this has been accomplished, 

 the toxic effects are very marked and rapidly fatal, the symp- 

 toms showing first in the parts nearest to the point of inocu- 



