ANTI-PNEUMOCOCCIC SERUM 411 



purulent pericarditis, and occasionally in peritonitis. The 

 pneumococcus is also frequent in chronic bronchial catarrh. 

 An agglutination reaction with patient's serum on the 

 pneumococcus is only very irregularly obtained and normal 

 serum rarely exerts any bactericidal effect upon the 

 organism. 



As regards opsonic determinations, freshly isolated 

 strains frequently fail to give any phagocytosis, and every 

 strain of pneumococcus gives a different amount of phago- 

 cytosis. For the control, the pooled serum of several 

 individuals should be used, and the culture should be 

 emulsified in distilled water. The serum of the Rand 

 native seems to have a very low opsonic content for the 

 pneumococcus compared with that of the European. 1 



Toxins. Auld separated a proteose and an organic acid 

 from the blood and organs of infected animals, and from 

 cultivations of the S. pneumonia in alkali- albumin the 

 same products were apparently obtained, the alkaline 

 medium soon becoming permanently acid. The proteose 

 on subcutaneous or intravenous injection produced some 

 fever ; on intra- thoracic injection fever and dyspnoea, and 

 post-mortem pleurisy and consolidation of the lung were 

 found. The organic acid produced slight rise of tempera- 

 ture, but no other symptom. Macfadyen 2 obtained an 

 endotoxin by triturating cultures with liquid air. 



Anti-serum. Immunity can be conferred on susceptible 

 animals by treating them with attenuated cultures, or 

 by inoculation with increasing doses of filtered broth 

 cultures of the virulent organism followed by doses of the 

 living organism. The blood-serum of such immunised 

 animals will protect other animals when injected, and an 

 anti-pneumococcic serum has been prepared by the fore- 

 going method. This anti-serum has been used in the 



1 Wright, Lancet, 1914, i, p. 1 et seq. 



2 Brit. Med. Journ., 1906, vol. ii, p. 776 (Refs.). 



