254 BIOLOGY OF PNEUMOCOCCUS 



and Avery, prepared what appeared to be a protein-free carbo- 

 hydrate from Pneumococcus II and which produced specific pro- 

 tection in mice. After dissolving the sediment from a twenty-four- 

 hour serum-broth culture in sodium taurocholate, the authors, by a 

 method much the same as that of Schiemann and Caspar, removed 

 the precipitate coming down on the addition of acetic acid, and 

 then separated the specific precipitable substance by alcohol. A 

 concentrated watery solution of the material was then treated with 

 a large amount of normal sodium hydroxide and the resulting sedi- 

 ment discarded. Upon the addition of alcohol to the clear fluid a 

 precipitate was obtained, which in a slightly acidified solution 

 failed to give any positive protein tests, had a dextro-rotatory 

 power of about +30° as compared with that of +74° for the 

 Type II carbohydrate of Heidelberger, and which on boiling with 

 hydrochloric acid yielded reducing substances. 



The carbohydrate preparation of Saito and Ulrich was strictly 

 type-specific, giving protection to mice against a Type II culture 

 but no protection against a Type III culture. It seems fair to as- 

 sume that their carbohydrate preparation was not so pure as the 

 corresponding preparation of Heidelberger and Avery since its 

 dextro-rotatory power was less (+30° against +74°) and also 

 since it contained 0.61 per cent of nitrogen. 



Schiemann 1226 employed the preparations made by Saito and 

 Ulrich in an attempt to immunize rabbits, and attributed his fail- 

 ure to the administration of too great dosage. In no instance was 

 it possible to produce agglutinins, precipitins, or protective anti- 

 bodies. He succeeded, however, in immunizing mice and in demon- 

 strating protective substances in their blood. 



Schiemann, Loewenthal, and Hackenthal 1231 continued the study 

 of pneumococcal carbohydrates and retested the conclusions of 

 Perlzweig and Steffen. 1081 From acid and alcohol precipitates of 

 dissolved Type I pneumococci extracts were made with methyl and 

 ethyl alcohol. The authors reported that the carbohydrate frac- 

 tion contained the larger proportion of the immunizing substance 



