358 MICROBIOLOGY 



is pronounced on the surface but upon agitation the brilliant 

 color appears throughout. There. are two pigments produced, 

 one a fluorescent green which is produced by other fluorescent 

 bacteria. 7 It is soluble in water but not in chloroform. A sec- 

 ond pigment, pyocyanin, which is of a bluish color, is also 

 produced. It is soluble in chloroform. This pigment differen- 

 tiates Pseudomonas pyocyaneus from other fluorescent bac- 

 teria. In addition to the ferment which causes liquefaction of 

 gelatin there is also one which has been named * ' pyocyanase, ' ' 

 and which has the power to dissolve bacteria, It has been 

 stated that it insures some protective power when injected into 

 animals. It has been used locally in case of diphtheria in 

 children. Park does not consider it of greater value than 

 other cleansing preparations in diphtheria. 



Resistance. This organism does not produce spores. It 

 is readily destroyed by the usual disinfecting solutions. It 

 is killed at a temperature of 60 C. for 10 minutes. 



Pathogenesis. This organism is pathogenic for pigeons, 

 guinea pigs and rabbits. Pigeons are especially susceptible. 



7 For a study of fluorescent bacteria, see Jordan, Botanical Ga- 

 zette, Vol. XXVII (1899) p. 19. 



