50 



T. TADOKORO. 



substance in the bark portion. It seemed to us therefore to be of 

 much scientific interest to investigate the chemical nature of this gummy 



ed with 2% ammoniacal solution over night. On the following morning, the 

 mixture was filtered off through a "Nutech" filter with suction, washed with 

 water and the residue was extracted with 5% caustic soda solution for 3 days 

 and filtered again. The filtrate was neutralized with dilute hydrochloric acid 

 and precipitated with alcohol. The precipitate was pat on filter, washed 

 with alcohol and ether and dried at 110°C, powdered and preserved for 

 hydrolysis. A part of the precipitate thus prepared was dissolved again in 

 potash solution and reprecipitated with hydrochloric acid. The precipitate 

 thus purified was dried over sulphuric acid in a partial vacuum and used for 

 optical research. 



Pentosan and methylpentosan of the substance were* determined by 

 the method of Ellet and Tollens i) with the following results. 



Pentosan in dry matter. 90.1% 

 Methylpentosan (as Rbamnosan) in dry matter. 11.3% 

 It is thus seen that the substance at hand consists entirely of pentosan 

 and methylpentosan. To determine the nature of the pentosan, the substance 

 was hydrolized and subjected to further investigation. 



Products of Hydrolysis. 



16 hours. At the end of the stated time, 

 le. When cooled it was filtered through a 



