272 



BIOLOGY OF PNEUMOCOCCUS 



MICRO-ANALYSIS OF THE CELLULAR CARBOHYDRATES OF THE 

 PNEUMOCOCCUS 



* Elek's modification of Pregl's micro method, 

 f Pregl micro-Kjeldahl method. 

 X Van Slyke method. 



By precipitating a concentrated neutral solution of the Type I 

 cellular substance with hydrochloric acid, Wadsworth and Brown, 

 just as Heidelberger, Goebel, and Avery had done, obtained an 

 acid-insoluble and an acid-soluble fraction. 



When tested with homologous antipneumococcic serum, both of 

 the fractions in a dilution of 1 to 6,000,000 gave precipitation. 

 When a Type I rabbit serum, which had been absorbed separately 

 with each fraction, was tested with the other, the acid-soluble frac- 

 tion failed to precipitate serum absorbed by either, while the acid- 

 insoluble fraction precipitated to a slight degree with the serum 

 absorbed with the acid-soluble portion. Unfortunately, no protec- 

 tion tests were carried out with the immune serum absorbed with 

 these fractions, so it is impossible to make a close comparison of 

 the results with those of Enders. 



Small doses of the Type I cellular carbohydrate were effective, 

 by intraperitoneal injection, in protecting mice against a fatal 



