BULLETIN OF THE BUSSEY INSTITUTION. 63 
but there were no indications of mannose-hydrazone. In the case 
of the evaporated liquor, 16 drops of phenylhydrazin acetate 
reagent, added to 1 cc. of the liquor, gave a yellowish-brown pre- 
cipitate, that formed slowly, in which after three hours a few 
crystals of dextrose-osazone were seen, and some balls insoluble 
in glacial acetic acid which were presumed to be mannose-hydra- 
zone. On standing over night both the mannose-hydrazone balls 
and the spiny osazone crystals had increased, and on recrystalliz- 
ing from diluted alcohol good mannose-hydrazone crystals were 
obtained. 
To test the effect of dilution, 1 cc. of water was added to 1 ec. 
of the liquor from the evaporation, and then 16 drops of the 
phenylhydrazin acetate solution. Next day the precipitate was 
seen to contain many crystals of dextrose-osazone and a few 
mannose-hydrazone balls. On again diluting, with 2 cc. of water, 
1 ce. of the liquor from the evaporation and adding 16 drops of 
the phenylhydrazin acetate reagent and allowing the mixture to 
stand over night, there were found a few dextrose-osazone crys- 
tals and some mannose-hydrazone balls also. 
But in other mixtures of dextrose and alkali made to illustrate 
what might happen in case the over neutralization of the product 
of an hydrolysis was but slight, no indications of mannose-hydra- 
zone were detected. ‘Thus, when 0.4 grm. of the pure dextrose, 
dissolved in 20 cc. of water and acidified with a few drops of 
strong hydrochloric acid, left at rest during twenty-four hours, 
then neutralized with sodium hydroxide to slight alkalinity and 
mixed with 12 drops of the phenylhydrazin acetate reagent, no 
indications of mannose were obtained, neither on testing the 
unevaporated liquor as it stood or after diluting it with water. 
Only amorphous precipitates and some dextrose-osazone crystals 
were to be seen after long standing. Similar negative results 
were encountered on evaporating the dextrose liquor to soft dry- 
ness, taking up with 4 cc. of water and adding 16 drops of the 
phenylhydrazin acetate reagent to 1 cc. of the liquor. No man- 
nose-hydrazone but an abundance of dextrose-osazone crystals 
were visible after the mixture had stood for a number of hours. 
So, too, on diluting with water some portions of the liquor from 
the evaporation, before adding the phenylhydrazin acetate reagent, 
only dextrose-osazone crystals, but no mannose-hydrazone were 
obtained. 
