236 PRACTICAL BACTERIOLOGY. 



gradually darker and darker until finally after eiglit 

 days it has assumed a rather intense rusty red colour. 

 No other known species of bacterium grows in a 

 similar manner upon potatoes, and therefore the 

 glanders bacillus may be invariably recognised by its 

 behaviour in these cultures. 



The glanders bacillus may be stained very readily 

 by any of the ordinary aqueous staining solutions ; 

 it is also very easily decolourised even by the weakest 

 reagents. On this account Gram's method cannot be 

 employed, nor can a contrast staining be accomplished.^ 

 A good method is to treat the cover-glass with warm car- 

 bolic fuchsine or carbolic methylene blue, and then to 

 rinse it either with pure distilled water or with water 

 containing at the very most -J^ °/^ of hydrochloric acid. 



As the glanders bacillus is pathogenic in man, it is 

 necessary to take the greatest care in performing all 

 experiments with it. By degrees the bacilli lose their 

 virulence, after having been repeatedly inoculated into 

 artificial media. 



Swine erysipelas, a disease very prevalent in Ger- 

 many, and also in some districts of other European 

 countries, and which is often very virulent, is caused 

 by very small slender bacilli, which are found in exceedr 

 ingly great numbers in the bodies of affected animals 

 which have died of the disease, especially in the capil- 



' See note on p. 212. 



