412 A MANUAL OF BACTERIOLOGY 



treatment of pneumonia and other pneumococcic infec- 

 tions, but the results have not been very encouraging. 

 The protective serum seems to produce aggregation of 

 the cocci when added to a culture of the diplococcus. 

 Klemperer and Washbourn found that the serum of con- 

 valescent patients possesses some degree of protective 

 power. The serum, however, withdrawn during the 

 pyrexial stage of the disease rather increases the suscepti- 

 bility of animals to pneumococcic infection. 



Vaccine. A vaccine prepared from cultures killed by 

 heat and standardised has been found of service in chronic 

 pneumococcic infections, and has also been employed in 

 acute croupous pneumonia. 1 Wright (loc. cit.) has also 

 recommended a vaccine for prophylactic inoculation against 

 pneumonia on the Rand, a dose of 1000 millions apparently 

 being the optimum for this purpose. 



Friedlander's Pneumo-bacillus 



This organism, already referred to above in the general 

 discussion of pneumonia, and originally believed by Fried- 

 lander to be the cause of the disease, has been obtained 

 by recent observers in only a small proportion of cases 

 of pneumonia. 



Morphology. The B. pneumonia is a very pleomorphic 

 organism, occurring in sputum or in the blood of an inocu- 

 lated animal generally as a short rod with rounded ends 

 surrounded by a marked capsule. It is non-motile, does 

 not form spores, and is readily stained with the ordinary 

 anilin dyes, but not by Gram's method an important 

 distinction from the S. pneumonia. In cultivations it 

 forms short rods, long rods, chains, and even filaments, 

 the capsule being absent, but this is regained on passage 

 through a susceptible animal. 



1 Willcox and Morgan, Brit. Med. Journ., 1909, vol. ii, p. 1050. 



