BACILLUS OF TETANUS. 401 



the bacteria in the culture from which they are obtained 

 and introduced with them into the tissues of the animal 

 at the time of the inoculation. In support of the latter 

 hypothesis : Mice have been inoculated with pure cul- 

 tures of this organism ; after one hour the point at 

 which the inoculation was made was excised and the 

 tissues cauterized with the hot iron ; notwithstanding 

 the short time during which the organisms were in con- 

 tact with the tissues and the subsequent radical treat- 

 ment, the animals died after the usual interval and with 

 the regular symptoms of tetanus. 



The poison produced by the tetanus bacillus, and to 

 which the symptoms of the disease are due, has been 

 isolated and subjected to detailed study ; some of its 

 peculiarities, as given by Kitasato, are as follows :* 



"When cultures of this organism are robbed of their 

 bacteria by filtration through porcelain, the filtrate con- 

 tains the soluble poison and is capable, when injected 

 into animals, of causing tetanus. 



" Inoculations of other animals with bits of the organs 

 of the animal dead from the action of the tetanus poison 

 produce no result ; but similar inoculations with the 

 blood or with the serous exudate from the pleural cavity 

 always result in the appearance of tetanus. The poison 

 is, therefore, largely present in the circulating fluids. 



" The greatest amount of poison is produced by culti- 

 vation in fresh neutral bouillon of a very slightly alka- 

 line reaction. 



" The activity of the poison is destroyed by an expo- 

 sure of one and one-half hours to 55 C. ; of twenty 

 minutes to 60 C. ; and of five minutes to 65 C. 



i Zeitschr. fur Hygiene, 1891, Bd. x. p. 267. 



