94 
Character  of  the  Urine. 
/  Am.  Jour  Pharm. 
\    February,  1896. 
glucose  is  not  desired.  This  test  is  applied,  according  to  Allen,  as 
follows  :  Equal  measures  of  urine  (2  c.c.)  of  normal  KOH  or  NaOH 
solution,  and  a  solution  of  safranine,  1  part  in  1,000  parts  of  water, 
are  mixed. 
The  mixture  is  heated  in  a  test  tube,  avoiding  agitation  as  much 
as  possible,  till  freely  boiling. 
If  the  urine  contains  more  than  01  per  cent.,  the  liquid  is  decolor- 
ized; otherwise,  the  red  color  remains  intact,  or  is  only  partially  dis- 
charged. 
If  the  color  is  destroyed,  the  test  may  be  repeated  with  twice  or 
three  times  the  volume  of  the  safranine  solution,  which  represents 
roughly  o-i  per  cent,  of  sugar. 
If  more  than  four  or  five  measures  are  required,  the  urine  is 
diabetic. 
If  this  test  is  applied  to  a  chrysophanic  urine,  containing  a  small 
percentage  of  glucose,  complete  decolorization  of  the  mixture  does 
not  take  place,  due  to  the  action  of  the  alkaline  excess  upon  the 
chrysophanic  acid. 
The  urine  must,  however,  contain  a  considerable  amount  of  the 
latter,  or  else  no  material  difference  is  noticeable. 
In  specimens  rich  therein,  this  interfering  action  can  be  plainly 
observed. 
Another  test,  dependent  upon  decolorization,  is  based  upon  the 
fact  that  potassium  ferricyanide,  commonly  known  as  red  prussiate 
of  potash,  in  alkaline  solution,  is  changed  to  ferrocyanide  in  the 
presence  of  glucose. 
It  has,  however,  been  shown  that  uric  acid  also  has  the  same 
effect. 
To  this  may  be  added  that,  in  chrysophanic  urine,  possibly  con- 
taining sugar,  no  such  decolorization  takes  place. 
The  excess  of  alkali  will  color  such  urine  red,  which  is  not  de- 
stroyed, even  upon  the  subsequent  addition  of  glucose. 
The  reliability  of  this  reaction  as  a  sugar  test  is,  therefore,  open 
to  criticism. 
Chrysophanic  urine  is  stated  to  be  eliminated  after  the  adminis- 
tration of  rhubarb  and  senna. 
Even  the  external  application  of  chrysarobin,  according  to  Rosen- 
th.il,  is  stated  to  produce  it  in  the  urine. 
In  the  experience  of  the  writer,  after  the  administration  of  large 
