314 Mary Davies Swartz, 



seaweed was therefore simply finely ground for use in feeding experi- 

 ments. 



It gave a strong furfurol test, but yielded a mere trace of mucic 

 acid. Tests for starch and reducing sugar were negative. The 

 products of hydrolysis contained no fermenting sugar. From this it 

 was evident that the hemicelluloses were chiefly pentosans. 



Determination of the reducing power gave the following results: 



TIME OF BOILING. 



Hours. 

 2 

 3 

 4 

 5 



Limu Pahapaha. Ulva lactuca is said by Rohmann (134) to con- 

 tain a water-soluble methyl -pentosan, rhamnosan; but if this occurs 

 in Limu Pahapaha, it must be in very small amount, as an extract 

 of 50 grams of the dried seaweed, made by boUing 3 or 4 hours, gave 

 very little residue on evaporation to dryness. For feeding experi- 

 ments, the dry crude substance was simply ground to a powder. 

 Like Limu Eleele, it gave a strong furfurol test, but yielded no mucic 

 acid. Starch was present, but no reducing sugar. Fermentation 

 with yeast was marked in 12 hours, probably due chiefly to the hy- 

 drolysis of the starch. 



Determination of reducing power gave the following results: 



TIME OF BOILING. SUGAR AS DEXTROSE. 



Hours. Per cent. 



2 28.8 



4 31.8 



GALACTAN PREPARATIONS, 



Irish Moss. 



The carbohydrates of Irish moss are, as already noted, readily 

 soluble in cold water, after the salt has been removed from the sea- 

 weed. By allowing the moss to stand for 24 hours in cold water (about 

 10 liters to 250 grams of dry substance), an almost colorless, semi- 

 transparent, mucilaginous extract was obtained. By straining this 

 off through gauze, and allowing it to stand over night, for minute 

 particles of cellulose held in suspension to settle, a solution almost 

 entirely free from insoluble material was obtained by decantation. 



