434 



Scientific Proceedings (132) 



hydrolysis of the collagen, although the organized skin struc- 

 ture inhibited diffusion of the enzyme and greatly decreased the 

 speed of the reaction. 



Specimens of collagen tanned with quinone, gallotannic acid, 

 copper sulfate and formaldehyde w r ere all hydrolyzed by trypsin 

 while chrome tanned collagen was not. 



216 (2176) 



The specific soluble substance of pneumococcus. 

 By M. HEIDELBERGER and O. T. AVERY. 



[From the Hospital of the Rockefeller Institute for Medical Re- 

 search, New York City.] 



In 1917 Dochez and Avery 1 showed that there was contained 

 in filtrates from pneumococcus cultures and in the body fluids 

 of experimentally infected animals and of patients suffering from 

 pneumonia, a soluble substance which reacts specifically in anti- 

 pneumococcus serum of the homologous type. This substance, 

 which was found to be thermostable, precipitable by alcohol or 

 acetone, non-dialyzable, and not digested by trypsin, is now 

 being subjected to a more intensive chemical study. 



Eight-day, autolyzed cultures of Type II Pneumococcus in 

 phosphate broth were concentrated to 1/15 volume and precipi- 

 tated with 1.2 volumes of alcohol. The precipitate, centrifuged 

 at high speed, yields a compact middle layer containing the 

 specific soluble substance. By repeated fractionation with alco- 

 hol or acetone, first in neutral, then in dilute acetic acid solution, 

 followed by repeated fractional precipitation with ammonium 

 sulfate and final dialysis, about 1 gm. of a highly purified prep- 

 aration was obtained for each 75 liters of culture used. 



In its present state of purity the specific soluble substance is 

 amorphous and yields a viscous solution in water. A 1 per cent, 

 solution gives no biuret test, yields no precipitate with phospho- 



i Docliez and Avery, J. Exp. Med., 1917, xxvi, 477. 



