368 BIOLOGY OF PNEUMOCOCCUS 



found further that antiprotein serum failed to agglutinate type- 

 specific strains of Pneumococcus or to react with the carbohy- 

 drate derived from them. A somewhat analogous reaction was de- 

 scribed in the same year by Jungeblut. 698 When alcoholic extracts 

 of washed, sedimented pneumococci of Types I, II, and III were 

 mixed with tincture of benzoin, added to specific immune serum, 

 and incubated at 40°, flocculation took place. Antipneumococcic 

 serums of the three types with homologous antigens gave floccula- 

 tion of varying intensity. The reaction was strictly specific for the 

 bacterial species and at the same time might be highly type-spe- 

 cific. 



SOMATIC CARBOHYDRATE (c FRACTION) 



A phenomenon first discovered by Tillett and Francis 1409 and 

 later investigated by Ash, 25 by Francis and Abernethy (1934), 475 

 by Abernethy and Francis, 2 and by Abernethy 1 still awaits an ex- 

 planation. 



It was found that the serum of individuals acutely ill with lobar 

 pneumonia possesses the capacity of precipitating the somatic or 

 C carbohydrate derived from pneumococci. It was further demon- 

 strated that the precipitating action of patients' serum with the 

 C Fraction is demonstrable in the early stages of pneumonia, 

 sometimes within twenty-four hours of the onset, persists through- 

 out the course of the active disease, or persists or recurs along 

 with the development of complications, and disappears during con- 

 valescence. 



In the report of the most recent experimental study available, 

 Abernethy 1 stated that the serum of rabbits infected intrader- 

 mally by the Goodner technique fails to precipitate the C carbo- 

 hydrate, whereas the serum of monkeys (Macacus cynomolgos) 

 given an intrabronchial infection with Type III Pneumococcus is 

 capable of precipitating the somatic polysaccharide. The prop- 

 erty is demonstrable within the first twenty-four hours following 

 the experimental inoculation and persists for two or three days 



