BACTERIUM MALLEI 453 



(manifested by elevations of body-temperature greater than 

 1.5° C.) to subcutaneous injections of mallein in from four 

 to ten hours, while an animal not so affected gives no such 

 reactions. 



Mallein is prepared from old glycerin-bouillon cultures of 

 the glanders bacterium by steaming them for several hours in 

 the sterilizer, after which they are filtered through unglazed 

 porcelain. 



By some it is said that the repeated injection of mallein 

 in small doses confers immunity from infection by bacterium 

 mallei upon animals so treated; an opinion that is entirely 

 in accord with the principles underlying the artificial induc- 

 tion of immunity in general. 



