(ICELAND MOSS). 191 



I. 1.021 grams isolichenin (ash-free) yielded on hydration 1.125 grams dex- 

 trose. Assuming a hydration equivalent to that of starch, the yield of 

 dextrose should hare been 1.134 grams. 



n. (a) In a solution of hydration products containing 1.23 per cent sugar 



(determined as dextrose) in a 200 mm. tube, an average of six polari- 



scopic readings gave a rotation of +1.25. Then (o) D = +50.8. 



(b) In a solution containing 1.13 per cent sugar in a 200 mm. tube, an 



average of six polariscopic readings gave a rotation of +1.17. Then 



The specific rotation of dextrose (o) D = +52.5. 



III. The osazones of the sugar formed were prepared and recrystallized four 

 times from alcohol. M. p. 199 C. The crystals resemble those of 

 phenylglucosazone in appearance and solubility. 



The hydration products of the isolichenin thus correspond 

 closely in behavior with those obtained from the lichenin of 

 the same plant. 



Action of enzymes and dilute HOI. Hb'nig and St. Schu- 

 bert* subjected this carbohydrate to the action of malt 

 diastase at 60 C. for several hours. They observed a rapid 

 disappearance of the iodine reaction and formation of dextrin- 

 like substance precipitable by alcohol. From such observa- 

 tions they class isolichenin their lichen starch with soluble 

 starch. The writer has further studied the action of saliva, 

 diastase, and pancreatic extract. Typical experiments are 

 given below : 



LAI per cent isolichenin solution was treated at 38 C. with saliva. 

 The " achromic point " was reached in about one minute, no erythro- 

 dextrin stage being detected. Digestion was continued for an hour. 

 The solution, tested from time to time, gave a slight reduction (with 

 Fehling's solution) which did not increase in amount. Nylander's 

 reagent gave no test for dextrose. The solution was precipitated with 

 alcohol and the filtrate gave no reaction for sugars after removal of the 

 alcohol. The precipitate of dextrin-like substance gave a slight reduc- 

 tion. t A flocky blue precipitate was always present in the test. 

 Towards diastase and amylolytic pancreatic extract isolichenin showed 

 similar behavior. 



n. Isolichenin was treated with varying strengths of HC1 (0.2-0.6 per cent) 

 at 38 C. for twelve hours. No sugar was obtained in any instance. 



Honig und St. Schubert, loc. cit., pp. 694-696. 



t Musculus and v. Mering (Zeitschr. fur physiol. Chemie, 1876, ii, pp. 410- 

 419) obtained from glycogen and starch achroodextrins which likewise 

 slightly reduce Fehling's solution. 



