ANovemb€rPhi9rio'  )     Detection  of  Dextrose  in  Urine.  717 
RELATIVE  SENSITIVENESS  OF  THE  FEHLING, 
PHENYL-HYDRAZINE  AND  NYLANDER 
TESTS  FOR  THE  DETECTION  OF 
DEXTROSE  IN  URINE. 
By  George  E.  Ewe, 
PHILADELPHIA,  PA. 
Standard  Material  Employed  in  Tests. — Merck's  chemically 
pure  dextrose  rendered  anhydrous  at  400  C,  dissolved  in  proper 
proportion  in  distilled  water  to  make  standard  solutions  of  the 
various  strengths  employed  in  the  tests.,  Since  the  experiments  ex- 
tended over  several  days  fresh  solutions  were  prepared  each  day. 
Nylander's  Test. — Formula:  Rochelle  salt  4  Gms.  dissolved  in 
100  Cc.  of  10  per  cent,  sodium  hydroxide  solution,  warm  and  add  2 
Gms.  bismuth  subnitrate. 
Application  of  Nylander's  Test. — One  volume  of  reagent  was 
added  to  10  volumes  of  dextrose  solution ;  the  mixture  then  being 
heated  for  5  minutes  in  boiling  water.  A  black  coloration  was  taken 
to  indicate  dextrose. 
Fehling's  Test. — Formula : 
Copper  sulphate  (cryst.)    34.639  Gms. 
Sod.  hydroxide  sol.  (sp.  gr.  1.120)    500  Cc. 
Rochelle  salt   173  Gms. 
Water  qs  1000  Cc. 
Dissolve  copper  sulphate  in  100  Cc.  warm  water  and  dissolve  the 
Rochelle  salt  in  the  sodium  hydroxide  solution.  Mix  these  2  solu- 
tions slowly  and  add  enough  distilled  water  to  make  a  yield  of 
1,000  Cc. 
Application  of  Fehling's  Test. — The  Fehling's  solution  was 
placed  into  a  test  tube  up  to  about  1  inch  from  the  bottom  of  the 
tube ;  the  solution  was  brought  to  a  boil  and  a  few  drops  of  the  dex- 
trose solution  was  added.  The  mixture  was  then  boiled  for  a  min- 
ute. If  no  apparent  reduction  was  observed  the  dextrose  was  added 
in  sufficient  quantity  to  obtain  a  reaction  but  not  in  greater  volume 
than  the  volume  of  Fehling  solution  employed  in  the  test.  In  ap- 
plying the  test  to  the  dextrose  solutions  having  a  percentage  of 
0.0625  per  cent,  or  less  equal  volumes  of  the  Fehling  solution  and 
