STUDY OF THE IMMUNITY AGAINST BACILLUS PYOCYANEUS 5 



they were destroyed. When a similar experiment was performed on a 

 well -vaccinated guinea-pig, the intra-cellular destruction of the bacilli 

 was quicker and more perfect. Gheorghiewsky thus attributes the 

 immunity against bacillus pyocyaneus to phagocytosis, and not to a 

 destruction of the bacilli by the serum. He was unable to demonstrate 

 any bactericidal action in the serum either in vitro or in vivo. 

 Incidentally Gheorghiewsky also noted a peculiarity of the immune 

 serum which had been observed by Charrin, viz., that it prevents the 

 bacillus from forming pyocyanin. 



P. Muller(S) was also unable to demonstrate any bactericidal powers 

 in pyocyanic immune serum in vitro in aerobic conditions of the experi- 

 ment. In anaerobic conditions, however, he considered that the 

 bactericidal action was very marked, and that it could be inhibited by 

 heating the immune serum to 55° C. The subsequent addition of a 

 normal serum to the inactive heated serum restored the bactericidal 

 power. 



Margarethe Breymann (6) made a special investigation into the 

 question of the toxicity of filtrates of pyocyanic cultures. The organism 

 grown in bouillon for periods varying from 7-50 days, was passed 

 through the Chamberland filter, the filtrate being inoculated into mice, 

 guinea-pigs and rabbits. She found that very large doses (100 c.c.) could 

 occasion death of rabbits, with great emaciation, quantities less than 

 this being practically without effect. Mice and guinea-pigs withstood 

 respectively doses of i c.c. and 40 c.c. of the filtrate. On concentrating the 

 filtrates over sulphuric acid, they were found to be non-toxic, even in 

 quantities representing 100 c.c. of the original filtrate. The cause of 

 this loss of toxicity was probably due to the disappearance of volatile 

 bodies — the toxic action of which had been already maintained by 

 Charrin (7). 



Maclntyre (S) grew bacillus pyocyaneus in large quantities on agar, 

 and after 14 days he precipitated with alcohol, collected the precipitate on 

 a hard filter, and extracted with alcohol and ether. He found that 5 mgr. 

 of the germ substance extracted in this way killed guinea-pigs, after 

 intra-peritoneal injection, in 12 hours. The amount injected was about 

 I -50,000th of the body weight of the animal. Injected subcutaneously, 

 one part of cell substance to 10,000 parts of body weight produced no 

 permanent ill effects. 



(161) M 



