322 



Mary Davies Swartz, 



that the rotation increases on standing, but in these solutions there 

 was no change in 48 hours, at room temperature. 



On hydrolysis, sinistrin yields a levo-rotatory, reducing sugar, fer- 

 menting with yeast. Schmiedeberg (318) reports this as a mixture of 

 levulose and an inactive sugar, but Reidemeister (314) declares that 

 it is neither a mixture of levulose and an inactive sugar, nor of levu- 

 lose and dextrose, in spite of the fact that he found for it la]D= —88°, 

 while for levulose, [a]D= —106°, a difference for which he is unable 

 to account. 



SUMMARY. 



The composition of the preparations which have been described is 

 best shown in the following table: 



SOURCE OF MATERIAL. 



NATURE OF CARBOHYDRATES PRESENT. 



Pentosans. Galactan. Mannan. 



Levulan. 



Deitran. 



Dulse {Rhodymenia Palmata) 

 Limu Lipoa (Haliseris Par- 



dalis) 



Limu Eleele {Enleromor pha 



intestinalis) 



Limu Pahapaha {Ulva lac- 



tuca, etc.) 



Irish Moss {Chondriis crispus) 

 Limu Manauea {Gracilaria 



coronopifolia) 



Limu Huna {Hypiiea nidifica) 

 Limu Akiaki {Ahnfeldtia con- 



cinna) 



Limu Uaualoli {Gymnogon- 



grus) 



Limu Kohu {Asparagopsis 



sanfordiana) 



Slippery Elm {Ulnius) 



Salep (Orchis.) 



Squills {Urginea scilla) [Sinis 



trin] 



+ 



+ 



+ 



+ 

 Trace 



+ 

 + 



+ 



+ 



+ 



Trace 



+ 



+ 

 + 



+ 



+ 



+ 

 + 



+ 



(Starch) 



+ 



+ 



+ 



The foregoing observations correspond with those of Konig and 

 Bettels (8), in that the marine algae all yield pentosans, and fre- 

 quently galactans. The gelatinizing principle in every case appears 

 to be due to the galactan groups. No specific tests have been applied 



