BULLETIN OF THE BUSSEY INSTITUTION. 29 
thrown down at once, both from the unevaporated and the evapo- 
rated liquor, and numbers of the small, oil-like globules were 
visible when the precipitates were examined with the microscope 
after standing foranhour. No indications of mannose-hydrazone 
appeared, though some pale green crystals of dextrose-osazone 
were seen after the mixture had stood for a day, and they in-' 
creased in number on longer standing. Both the oil-like Ee 
' and the osazone crystals were soluble in glacial acetic acid. 
Other kinds of globules, — dark and thick and often of reddish’ 
color, —of very different appearance from that of the oily drops 
just mentioned, have been encountered occasionally in the original 
precipitates produced on the addition of the phenylhydrazin 
reagents to products from the hydrolysis of woods. Usually 
these large, dark-colored globules, like most of the globules other 
than those of mannose-hydrazone which have been met with in 
this research, are soluble in cold glacial acetic acid when recently 
prepared, though they become much less soluble in the acid after 
long standing. Occasionally they are somewhat difficultly soluble 
in the acetic acid even when fresh; indeed, some specimens ob- 
tained on testing commercial ‘‘ glucose,” as mentioned above on 
page 26, and in one instance on testing pure dextrose, were hardly 
any more soluble in glacial acetic acid than mannose-hydrazone 
itself, and their appearance was remarkably like that of mannose- 
hydrazone globules, though no crystals could be obtained from 
them by treatment with diluted alcohol. According to Tollens,* 
Hirschl, on meeting with analogous ‘*‘ braune Ktigelchen” when 
testing urine for sugar, suggested that they might perhaps depend 
on the presence of gluconuric acid, —an idea which was naturally 
more probable in the case of the urine he was testing than it 
would be for dextrose or ‘‘ glucose,” for urine not infrequently 
contains gluconuric acid. 
* Handbuch der Kohlenhydrate, 2. 100. 
