K. MtTAKE : On the Natdee op the Sugars found in the Tuber« of Abbowhead. 25 



IVIucic acid producing subsfciiice by oxidation . l.-13J'jj' (as galactose). 



Insolulilo in 95% alcohol O.ßOO^ ( „ ). 



Soluble iu 95% alcohol 0.71^ ( „ ). 



Pentosane (including methyl pentosauc) .... 1-SS% 

 As has been shown iu the above table, of tlie carbohydrate constituents, 

 starch is a prominent substance, its amount attaining 55.32% of the dry matter. 

 Sugars are also present iu no slight quantity, reaching the amoimt of 6.21_%' of the 

 dry matter, and they constitute an important part of the carbohydrate coustitueuts. 

 To determine the exact natiu-e of the sugai-s of tlie arrowhead tubers, the 

 follo^ying investigation was undertaken according to plan herein described. 



1. Preparation of the syrnp. 



The arrowhead tubers were peeletl of their rind and finely chopped. The 

 chooped parts were allowed to dry in the air, requiring about two weeks for dry- 

 ing to such a state tliat they could be groimd easily and finely pulverized. 



The preparation of the syrup was begun by exti-acting 100 grams of the 

 finely pulverized material iu a Soxhlet apparatus with ether. The residue so 

 obtained, ■which was freed from oU, after evaporathig ether, was placed iu 750 cc. 

 flask fitted with inverted condenser and treated daily with 300 cc. of 95^ alcohol 

 heated in a boiling water bath. The extract was at first of a deep yellow colour, 

 but it gradually became lighter from day to day. It had a sweetish taste and 

 was nearly neutral to litmus dming the entire time of extraction. One week was 

 requii'ed to remove the last ti-aces of sugare. The combined extracts were filtered to 

 remove the sediment wliich was formed in standing, and the filtrate was evap(irated 

 to a small volum(i in a partial vacuum. The concentrated liquor was again extracted 

 many times with a small quantity of absolute alcohol, until, after the evaporation 

 of the alcohol, no more residue was produced. The residue (I) here obtained was 

 preserved in a desiccator as material for the later iuvestigation. The exti-acts 

 were coucenfauted to a syrupy condition in a partial vacuum and allowed to dry 

 over sulphuric acid. 



Above method of the preparation was repeated about ten times to get a 

 sufiicient quantity of the materials for investigation. 



2. Fx±yermient tvith the syrup. 



ji. Qualitative tests. 



The syrup obtained above, gave the following qualitsitive reactions : — 



