382 BACTERIOLOGY. 



were ia contact with the tissues and the subsequent 

 radical treatment, 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 

 contains 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 inocula- 

 tions 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 

 cultivation in fresh neutral bouillon of a very slightly 

 alkaline reaction. 



" The activity of the poison is destroyed by an 

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

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



" By drying at the temperature of the body under 

 access of air the poison is destroyed, but by drying at 

 the ordinary temperature of the room, or at this tem- 

 perature in the desiccator over sulphuric acid, it is not 

 destroyed. 



"Diffuse daylight diminishes the intensity of the 

 poison. Its intensity is preserved for a much longer 

 time when kept in the dark. 



1 Zeitschr. fUr Hygiene, 1891, Bd. x. p. 267. 



