PNEUMONIA. 351 



tion as to allow of frequent relapses ; and it is well known 

 that many cases show a subsequent predisposition to 

 fresh attacks of the disease. This brevity of immunity 

 lessens the probability that in the future we shall dis- 

 cover an antitoxin that shall be powerful in its influ- 

 ence upon the course and termination of the disease. 



The experiments of G. and F. Klemperer, a few years 

 ago, showed that the serum of immunized rabbits pro- 

 tected animals inoculated with the pneumococcus. The 

 principle failed, however, when applied to human medi- 

 cine. The treatment of pneumonia by the injection of 

 blood-serum from convalescents has also been abandoned 

 as useless and dangerous. 



Washbourn has recently prepared an antipneumococcic 

 serum which is efficacious in protecting rabbits against 

 ten times the fatal dose of live pneumococci. In general, 

 the lines upon which he operated were those of Behring, 

 Marmorek's work with the streptococcus furnishing most 

 of the details. A pony was subjected to immunization 

 for a period of five months, allowed to rest three or four 

 months until the live pneumococci introduced were all 

 destroyed, and then bled. Two cases of human pneu- 

 monia seem to have received some benefit from the injec- 

 tion of large doses of this serum. 



The pneumococcus causes other lesions than croupous 

 pneumonia; thus, Foa, Bordoni-Uffreduzzi, and others 

 have found it in cerebrospinal meningitis; Frankel, in 

 pleuritis; Weichselbaum, in peritonitis; Banti, in peri- 

 carditis; numerous observers have found it in acute ab- 

 scesses; Gabbi has isolated it from a case of suppurative 

 tonsillitis; Axenfeld has observed an epidemic of con- 

 junctivitis caused by it; and Zaufal, Levy, and Schrader 

 and Netter have been able to demonstrate its presence in 

 the pus of otitis media. It has also been reported as oc- 

 curring in the joints in arthritis following pneumonia. 



The pneumococcus is often present in the mouths of 

 healthy persons. The conditions under which it enters 

 the lung to produce pneumonia are not known. 



