BACTERIAL INOCULATION 271 



ish-yellow, followed by rapid drying and crust forma- 

 tion. Involution begins usually about the tenth day 

 and by the end of the second week only a thick, brown, 

 tightly adlierent crust surrounded by pigmented skin 

 marks the original site of the papule. 



From the standpoint of therapy it is of interest to 

 note that recently autogenous staphylococco-bacterins 

 prepared from the pustules of smallpox have been 

 successfully used in diminishing the degree of cutane- 

 ous pitting. 



Bubonic Plague, — Treatment with bacterial sus- 

 pensions of B. pestis has been extensively practiced 

 by HafFkine. Prophylactic inoculation is of much 

 greater value than therapeutic administration, and 

 has reduced the mortality from 66.6 to 16.6 per cent, 

 in the experience of Strong, who employed living 

 attenuated bacilli. The primary immunizing dose 

 should be five billion bacteria, followed in ten days by 

 ten billions. Immunity is alleged to endure from 

 three to eighteen months. Therapeutic inoculation 

 greatly reduces the severity of attacks, and recovery 

 always occurs if the victim be a European. Cura- 

 tively, however, Yersin's or Lustig's antitoxic serum 

 supersedes bacterin as a therapeutic measure. Bac- 

 terins are probably valueless in the septiceemic and 

 pneumonic forms of the disease. 



