7 'HE PIS. I C CHARIDRS. 
ii 
Maltose reduces copper, bismuth, and other metallic salts in alkaline 
solutions, 1ml its reducing power as measured by Fehling's solution is 
about one-third Less fchau thai of dextrose. 1 It dors not reduce Barfoed's 
reagent 2 as dextrose does. It ferments readily with yeast. With 
phenylhydrazine, phenylmaltosazone is formed (< '.,,II : .;X,< >,,): this crystal- 
lises in yellow needles much broader than those yielded by dextrose or 
lactose; it melts at 206 C. Unlike phenylglucosazone, it dissolves 
in seventy-five parts of boiling water, and is still more soluble in hot 
alcohol ( Fig. 2). 
Fig. 2. — Crystals of phenylmaltosazone. 
Tsomaltose 3 is a sugar formed at the same time as maltose by the 
action of either diastase, ptyalin, or amylopsin 4 on starch. It is also an 
1 Ten c.c. of Fehling solution corresponds to - 05 gnus, of dextrose, levulose, or galactose, 
and to '07 196 of maltose. 
2 13'3 grms. of cupric acetate are dissolved in 200 c.c. of water; to this solution, 
6 c.c. of acetic acid containing 38 per cent, of glacial acetic acid are added (Barfoed, 
"Organic Analysis," p. 254). 
3 Originally described by Fischer, Bcr. d. dcv.tsdi. chem. Gesellsch., Berlin, Bd. xxiii. 
S. 3687. Fischer's observations, which have been called in question by some chemists, have 
been very generally continued. In his most recent paper on the subject, ibid., 1896, Bd. 
xxvii. S. 3024, he shows that isomaltose is not directly fermentable by yeast, and so may be 
separated from maltose. Its osazone is soluble in four parts of hot water, while that from 
maltose requires seventy-five parts. 
4 Ruiz and Vogel, Ztschr.f. Biol., Miinchen, Bd. xxxi. 
