CHEMICAL CONSTITUENTS 255 



and that the alcoholic extracts showed varying specific immunizing 

 properties, which they believed might be due to the presence of 

 small amounts of the type-specific carbohydrate carried over by 

 the alcohol. It was found, furthermore, that watery solutions of 

 the carbohydrate still produced immunity in dilutions which no 

 longer gave precipitation. 



The protein-free substance of Schiemann and his associates, 

 purified by repeated alcohol precipitation in alkaline solution, 

 showed +264° 10' angle of refraction with polarized light (com- 

 pare +300° for Heidelberger and Avery's Type I polysaccharide), 

 and with hydrochloric or nitric acids at 80° yielded no reducing 

 sugars. The authors noticed the characteristic differences in the 

 appearance of the precipitates obtained with specific immune 

 horse and rabbit serum — the former appearing sooner and being 

 coarser, while the latter were fine and formed a transparent mem- 

 brane. The purified preparation actively immunized mice in doses 

 of 0.001 to 0.0001 milligrams but failed to do so when injected in 

 amounts greater than 0.01, or less than 0.00001 milligrams, and 

 therefore acted in a narrower zone than the less pure fractions pre- 

 pared by the method of Schiemann and Caspar. 1228 



In contrast to the immunizing action of the carbohydrate frac- 

 tions of Pneumococcus in mice, as reported by Perlzweig and 

 Steffen, Schiemann and Caspar, Saito and Ulrich, and Schiemann, 

 Loewenthal and Hackenthal, the polysaccharides from Type I, II, 

 and III pneumococci were devoid of any power to sensitize guinea 

 pigs to these specific carbohydrates. When single initial doses of 

 ten, twenty, and fifty milligrams of the preparations were injected 

 the animals failed to react when given a shocking dose of one to ten 

 milligrams twenty-one days later. This same shocking dose, how- 

 ever, produced rapid and fatal anaphylactic shock when injected 

 into guinea pigs passively sensitized with the precipitating serum 

 of rabbits immunized with pneumococci of the homologous type. 

 The experiment afforded evidence of a striking difference, there- 

 fore, between the antigenic and haptenic action of preparations of 



