7x8  Detection  of  Dextrose  in  Urine.  {A™mimbe*%r^: 
dextrose  solution  were  employed,  boiled  for  one  minute  and  set 
aside  for  one  half  hour  to  allow  any  precipitate  to  settle. 
In  all  the  tests  blanks  were  run  on  the  Fehling  solution  using 
distilled  water  in  place  of  the  dextrose  solutions. 
Phenyl-Hydrazine  Test. — Formula :  A  mixture  of  I  Gm.  Phenyl- 
hydrazine  hydrochloride,  2  Gms.  sodium  acetate,  and  10  Cc.  water 
was  shaken  together  and  2  drops  of  glacial  acetic  acid  was  added. 
The  solution  was  again  shaken  well  and  then  filtered  clear.  This 
reagent  was  prepared  fresh  daily  in  these  experiments. 
Application  of  Phenyl-Hydrazine  Test. — Five  Cc.  of  the  reagent 
was  added  to  10  Cc.  of  the  dextrose  solution  in  a  test  tube.  The 
tube  was  placed  in  a  beaker  of  boiling  wTater  and  the  water  was 
boiled  for  one  hour.  The  tube  was  then  removed  from  the  boiling 
water  and  allowed  to  stand  at  room-temperature.  The  appearance 
of  the  characteristic  crystals  of  phenyl-glucosazone  in  the  test  was 
taken  as  a  positive  reaction.  In  solutions  of  dextrose  of  0.125  per 
cent,  strength  and  above,  the  crystals  were  formed  in  the  hot  liquid 
in  less  than  an  hour  from  the  beginning  of  the  application  of  the 
heat.  In  solutions  of  0.0625  per  cent,  and  less,  the  crystals  formed 
after  boiling  for  one  hour  and  allowing  to  cool  for  various  periods 
of  time. 
Keeping  Qualities  of  Phenyl-Hydrazine  Test  Solution  for  the 
Detection  of  Dextrose  in  Urine. — Phenyl-hydrazine  test  solution  is 
not  a  perfectly  stable  solution,  but  possesses  much  greater  stability 
than  it  is  usually  credited  with.  The  following  experiments  tend 
to  prove  this : 
A  quantity  of  the  test  solution  was  prepared  as  mentioned  above 
and  placed  in  an  amber-glass  bottle  equipped  with  a  ground-glass 
stopper.  This  supply  of  solution  was  kept  at  room  temperature  for 
19  days  and  tested  for  sensitiveness  at  various  times  during  that 
period.   The  results  of  these  tests  follow : 
Strength  of  Dex-  Age  of  Test 
trose  Solution  Solution  Reaction 
0.005  per  cent              Fresh.  Positive  after  cooling  and  standing  45  min. 
0.005  per  cent  2  days.  Positive  after  cooling  and  standing  55  min. 
0.005  per  cent              6  days.  Positive  after  cooling  and  standing  75  min. 
0.005  per  cent  10  days.  Positive  after  cooling  and  standing  90  min. 
0.005  per  cent  19  days.  Negative  after  cooling  and  standing  24  hrs. 
The  comparative  sensitiveness  of  the  three  tests  for  the  detection 
of  dextrose  in  urine  are  shown  in  the  following  table : 
