298 Pneumonia 



Bacteriologic Diagnosis. It is usually unnecessary to 

 call upon the bacteriologist to assist in making the diagnosis 

 of pneumonia. If necessary, the expectoration can be 

 examined by the methods already given for staining the 

 pneumococcus, or rabbits may be inoculated and the organ- 

 ism recovered from the blood. Caution must be exercised 

 in using this means of diagnosis, however, as the organ- 

 ism sometimes occurs in normal saliva, and is a common 

 associated organism in tuberculosis and other respiratory 

 diseases. Wadsworth* has been able to show that agglu- 

 tination reactions can be obtained by concentrating the 

 pneumococci in isotonic solution and adding the serum. 

 The method does not seem easily applicable for diagnosis. 



Buergert found that all pneumococci irrespective of 

 source were agglutinated by pneumococcus immune serum, 

 that such serum was capable of agglutinating various pyo- 

 genic streptococci, certain atypical organisms and certain 

 strains of Streptococcus mucosus capsulatus. The sera of 

 pneumonia patients varies in its power to agglutinate 

 different pneumococci; some strains were agglutinated, 

 others not. The sera of normal individuals and of normal 

 rabbits possess no agglutinating power for pneumococci, the 

 atypical organisms, certain streptococci and the Strepto- 

 coccus mucosus capsulatus. 



Immunity. Pneumonia is peculiar in that recovery is 

 followed by immunity of such brief duration as to permit 

 the occurrence of frequent relapses; and it is well known 

 that many cases show a subsequent predisposition to fresh 

 attacks of the disease. 



Immune Serum. G. and F. Klemperer J have shown 

 that the serum of rabbits immunized against the pneumo- 

 coccus protects animals infected with virulent cultures. 

 When applied to human medicine, the serum failed to 

 do good. 



The treatment of pneumonia by the injection of blood- 

 serum from convalescent patients, tried by Hughes and 

 Carter has been abandoned as useless and dangerous. 



More recent antipneumococcic serums have been experi- 



*"Jour. Med. Research," vol. x, p. 228, 1904. 

 f"Jour. Exp. Med.," Aug. 25, 1905, vn, No. 5. 

 J " Berliner klin. Wochenschrift," 1891, Nos. 34 and 35. 

 "Therapeutic Gazette," Oct. 15, 1892. 



