244 BIOLOGY OF PNEUMOCOCCUS 



Goebel, Morgan, and Neill, which contained descriptions of refine- 

 ments in the methods of preparing these polysaccharides and of 

 their physical, chemical, and immunological properties. Because of 

 their importance the data are presented here in considerable de- 

 tail ; and in order that the reader may be offered a full, connected, 

 and authentic account of the results of these basic studies, the 

 liberty is taken of quoting from and paraphrasing Heidelber- 

 ger's 604 " 5 comprehensive discussions in 1927 of the chemical nature 

 of the antigenic substances of Pneumococcus. 



The type II Pneumococcus was first studied and the fractionation 

 and purification of the specific substance were followed at each step by 

 means of the precipitin test. ... As the purification proceeded the 

 material isolated took on more and more the properties of a polysac- 

 charide, so that it became evident that a sugar derivative was at least 

 the carrier of whatever might be the true specific substance itself. At- 

 tempts were made to separate this hypothetical substance from the 

 polysaccharide by precipitation with basic lead acetate, uranyl nitrate, 

 or safranine, by adsorption with alumina and recovery from this, and 

 even by specific precipitation with a large quantity of Type II anti- 

 body solution (prepared by Felton's method), and recovery of the spe- 

 cific substance from the immune precipitate, but these failed to effect a 

 significant change in properties, even when pneumococci themselves 

 were used as starting material instead of the broth culture. Attempts at 

 a separation by means of certain carbohydrate-splitting enzymes also 

 failed since the sugar derivative proved resistant to this type of hy- 

 drolysis. Moreover, when exposed to the action of 1 : 1 hydrochloric acid 

 in the cold, the substance diminished in specific activity only after re- 

 ducing sugars began to appear, so that the specific substance and the 

 polysaccharide, if not identical, appeared at least to be very closely 

 associated. On hydrolysis the specific product yielded about 70 per cent 

 of reducing sugars consisting mainly of glucose, as shown by the isola- 

 tion of glucosazone and the formation of saccharic acid on oxidation. 

 Other possible constituents remained unidentified. 



Marked differences were found between the soluble specific sub- 

 stance of Type III Pneumococcus and the corresponding deriva- 

 tive of Type II. The former proved to be the soluble salt of an in- 



