270 BIOLOGY OF PNEUMOCOCCUS 



supercentrifuge and washing the sediment in distilled water. The 

 supernatant fluid and washings were evaporated over the free 

 flame to small volume and then used for the isolation of the specific 

 carbohydrate by the method of Heidelberger and Avery. The 

 preparation contained about 5 to 6 per cent of nitrogen. Its solu- 

 tion gave negative biuret and xanthoproteic tests, a positive Mo- 

 lisch test, did not reduce Fehling's solution until after hydrolysis 

 with hydrochloric acid, and was precipitated by phosphotungstic 

 acid. The material was more readily soluble in water than the 

 polysaccharide of Heidelberger and Avery. 



When tested against antipneumococcic serum, the dissimilarity 

 between the substance prepared by Wadsworth and Brown and the 

 soluble specific substance of Heidelberger and Avery and its simi- 

 larity to the A substance of Enders became evident. It precipitated 

 specifically in Type I serum in a dilution of 1 to 6,000,000, but in 

 a dilution of 1 to 600,000 it gave an immediate ring reaction with 

 Type I serum which had been completely absorbed with a highly 

 purified preparation of the soluble specific substance. Wadsworth 

 and Brown did not test the supernatant fluid from the serum pre- 

 cipitated with SSS for protective antibody. 



Again differing in properties from the Heidelberger and Avery 

 polysaccharide, the substance induced immunity in mice, as dem- 

 onstrated by the protection test. The immunizing effect was type- 

 specific. The substance fixed complement in the presence of Type I 

 antipneumococcic rabbit serum and while it caused no reaction 

 when injected intravenously in a dose of one milligram into a nor- 

 mal guinea pig it evoked fatal anaphylactic shock in guinea pigs 

 passively sensitized not only with Type I antipneumococcic rabbit 

 serum but with the same serum after removal of precipitin by ab- 

 sorption with the soluble specific substance. Wadsworth and 

 Brown concluded that the substance they had isolated from the 

 pneumococcal cell corresponded to that of Schiemann and his co- 

 workers, and to the A substance of Enders, but was distinct from 

 the soluble specific substance of Heidelberger and Avery. 



