THE DIPLOCOCCUS PNEUMONIA 143 



Clinical Examination. With sputum the microscopical 

 examination and the inoculation of a drop into the 

 peritoneal cavity of a mouse give more reliable results 

 than culture methods, since other species of organisms 

 are frequently present; but with pus and exudations pure 

 cultures can generally be obtained. 



Pathogenesis. D. pneumonia? is pyogenic and may be 

 found in broncho - pneumonias, pleurisy and empyema, 

 endocarditis and pericarditis, meningitis (one- third of 

 the cases), peritonitis, arthritis, osteomyelitis, and con- 

 junctivitis. It can apparently also produce inflammation 

 of the throat, with the formation of a false membrane, 

 and is sometimes met with in this situation in association 

 with the diphtheria bacillus. It frequently occurs in the 

 healthy mouth. As it occurs naturally, its virulence is 

 subject to great variation. In its clinical features pneu- 

 monia presents strong resemblances to the specific fevers, 

 and though isolated cases are most common, epidemics 

 do occasionally occur. The diplococcus is very fatal to 

 mice on subcutaneous or intraperitoneal inoculation, 

 less so to rabbits and guinea-pigs, while pigeons and fowls 

 are immune. Antipneumonic serum has not given very 

 satisfactory results. 



Vaccine Treatment. Willcox and Morgan commence 

 treatment with a stock vaccine, while an autogenous 

 vaccine is being prepared by culture: (1) from sputum; 

 (2) from blood; or (3) by aspiration of the pleural cavity 

 or superficial part of the consolidated lung by a small 

 syringe with a fine needle. Vaccine treatment has 

 sometimes been found beneficial. 



Resistance. When protected by an albuminous coat- 

 ing the pneumococcus may retain its vitality for three or 

 four months, and has been found in the dust of a room 

 occupied by pneumonic patients and in the dust of 

 hospital wards. 



Mice may play an active part in the dissemination of 

 pneumonia, particularly the epidemic variety (Gamaleia), 



The Pneumo-Bacillus of Friedlander. 



This organism, in the sputum, occurs as a short rod 



1 fji to 2 /a in length, with rounded ends, though longer 



forms are seen. In the exudations it is encapsuled, and 



frequently occurs in pairs. It is non-motile and non- 



