# 
68 BULLETIN OF THE BUSSEY INSTITUTION. 
to the filtrate from the first precipitate, was treated like the 
first precipitate, but no indications of mannose-hydrazone were 
manifested. 
These negative results, obtained on testing maple sugar and 
maple syrup, agree with those of Pellet,* who has declared that 
fresh cane juice contains no mannose, but they differ decidedly 
from those published by several chemists who have tested molasses 
derived from the sugar-cane.T 
The reason of this apparent discrepancy is that in the making 
of sugar from the sugar-cane the alkali lime is used for clarifying 
the cane juice, and that some mannose is formed by the action of 
this lime upon dextrose contained in that juice. But in the pro- 
cess of preparing sugar from the sap of the maple tree lime is 
seldom or never used, and there can consequently be very little 
chance of encountering any mannose that has been introduced 
into the product in that way. It may be remarked, furthermore, 
in passing, that Fischer and Hirschberger were unable to detect 
mannose either in honey or in grape juice. See abstract in Hoff- 
mann’s Jahresbericht der Agrikulturchemie, 1888, 31. 331. 
I have yet again to thank my assistant, Mr. F. T. Dillingham, 
most heartily for aid in this research. 
* Bulletin de l’Association des Chimistes de Sucrerie et de Distillerie de 
France et des Colonies, April, 1901, 18. No. 10, page 758. 
+ See, for example, Lobry de Bruyn and Ekenstein. Recueil des Travaux 
Chimiques des Pays Bas, 1895, 14. 215, 16. 280; Prinsen Geerlig, Bulletin 
de l’Association des Chimistes de Sucrerie et de Distillerie de France et des 
Colonies, 14. 1080; and Pellet, zb7d. 1901, 18. No. 10, page 758. 
