Am'juiy?iS16artt1'}        Some  Recent  Sitgar  Reactions.  359 
regards  all  individuals  whose  urine,  one  hour  after  the  consumption 
of  1 50  grammes  of  wheat  bread,  shows  an  increased  amount  of 
inverted  sugar,  as  future  diabetics. 
If  this  statement  is  correct,  the  presence  of  glucose  in  urine, 
under  such  conditions,  is  of  more  than  passing  importance. 
Unfortunately,  the  detection  of  small  amounts  of  glucose  in  urine 
is  not  an  easy  matter. 
Other  urine  constituents  interfere,  and  a  test,  absolutely  trust- 
worthy and  easily  applied,  remains  as  yet  to  be  found. 
The  medical  and  pharmaceutical  press  frequently  publishes  new, 
or  modifications  of  old,  sugar  reactions,  but  on  thorough  trial  most 
are  found  defective. 
The  copper  reactions  still  appear  to  possess  the  confidence  of 
most  urine  analysts,  and  a  number  of  modifications  have  been  sug- 
gested. 
The  fact  that  some  coal-tar  dyes  in  alkaline  solution  are  changed 
to  leuco-derivatives,  colorless  compounds  in  the  presence  of  glucose, 
is  taken  advantage  of  in  examining  diabetic  urine. 
The  two  most  prominent  are  Wender's  methylene  blue  and 
Crissler's  safranine  tests. 
The  former  has  been  stated  to  be  affected  by  uric  acid,  and  con- 
sequently cannot  be  regarded  as  possessing  any  advantage  over 
Fehiing's  solution. 
The  rapid  absorption  of  oxygen  by  the  reduced  liquid,  tending  to 
restore  the  original  blue  color,  is  another  feature  which  detracts 
from  the  value  of  this  test. 
The  Safranine  Test. — Brief  mention  was  made  of  this  reaction  in 
the  January  Pharmaceutical  Meeting  in  connection  with  chrysophanic 
acid  urine. 
Safranine  occurs  in  commerce  as  a  brown  powder,  soluble  in 
water  and  alcohol. 
Technically  it  is  used  for  dyeing  cotton  red,  with  a  mordant  of 
tannin  and  tartar-emetic. 
It  is  stated  that,  on  the  addition  of  an  alkali,  safranine  solution 
will  not  precipitate  immediately,  but,  on  standing  some  time,  more 
or  less  precipitation  will  take  place. 
The  test  is  applied  as  follows  (reprinted*  from  Am.  Jour.  Pharm., 
Vol.  68,  p.  94) : 
Equal  measures  of  urine  (2  c.c),  of  normal  NaOH  or  KOH  solu- 
