374 Maugham.—Observations on the Osazone Method 
Heated 75 mins. 
On cooling. 
After 4 days. 
After 5 weeks. 
Cane sugar. ( a ) 
Very slight precipitate. 
Very slight precipitate. 
Very slight precipitate. 
„ „ (?) 
Quite clear. 
Quite clear. 
Quite clear, except top layer. 
Maltose. (a) 
Little change. 
Little change. 
Film at top; liquid rather 
turbid. No osazone crystals. 
,, (*) 
Quite clear. 
Quite clear. 
Quite clear, except top layer. 
Control. ( a ) 
Little change. 
Little change. 
Film at top ; liquid turbid ; 
yellow-brown deposition on 
sides of tube. 
„ (*) 
Quite clear. 
Quite clear. 
Quite clear, except top layer. 
Several conclusions may be drawn from the above results, though 
the experiment was merely a preliminary one and by no means strictly 
quantitative : 
1. In the presence of excess of pure glycerine the formation of 
crystalline osazones may be hindered or entirely prevented. 
2. This effect appears to be more pronounced with maltose and 
dextrose than with levulose. 
3. In the presence of water (in excess) chemical changes occur leading 
to the formation of brown substances, but glycerine (in excess) tends to 
prevent or retard these changes. Their first appearance at the surface 
exposed to air suggests that these changes are oxidation processes. They 
extend into the pure glycerine mixtures more slowly than into the aqueous 
ones. 
4. The reagent itself in the presence of excess of pure glycerine under¬ 
goes no appreciable change even after being heated at about ioo° C. for 
more than an hour; the addition of water, however, brings about the 
changes referred to in 3. 
5. Cane sugar may yield a small quantity of osazone crystals if heated 
for more than an hour, 1 though excess of glycerine was found to prevent 
the reaction in this particular instance. 
Some quantitative experiments were then made in the following 
manner: 
Experiment II. Weighed amounts of the dry, powdered sugars were 
introduced into glass tubes and just dissolved in a drop or two of water. 
Carefully mixed reagent was then added in known weight. 
The respective tubes contained cane sugar, (1) 1 per cent. (i. e. 0*03 gr. 
sugar and 2*0 gr. reagent), (2) 10 per cent. (i. e. 0*20 gr. sugar and 20 gr. 
reagent); dextrose, 1 per cent.; levulose, 1 per cent.; and maltose, (1) 1 per 
cent., (2) 10 per cent. 
1 Cf. below, p. 375. 
