92 
Character  of  the  Urine. 
J  Am.  Jour.  Pharm. 
\    February,  1896. 
Thus  employed,  this  test  will  not  be  affected  by  chrysophanic 
acid  urine,  as  the  lead  salt  will  precipitate  the  latter.  But  if  the 
following  modification  is  employed,  a  different  result  may  take 
place  : 
Three  grammes  of  lead  acetate  are  dissolved  in  io  c.c.  of  urine, 
by  heat,  filtered  and  the  still  hot  filtrate  treated  with  ammonia. 
On  heating  the  mixture  to  boiling,  the  above-mentioned  color 
will  be  developed  in  the  presence  of  glucose. 
In  following  this  method  with  chrysophanic  acid  urine,  part  of 
the  acid  does  not  seem  to  be  completely  precipitated  and  to  pass 
into  solution,  when,  upon  the  addition  of  ammonia,  also  a  red  color 
will  be  produced,  as  in  the  case  of  glucose. 
Some  care  is,  therefore,  necessary  in  employing  this  test. 
(3)  Reaction  with  copper  solutions. — The  usual  method  for  the 
examination  of  urine  for  sugar  consists  in  observing  the  action  upon 
boiling  diluted  Fehling's  solution. 
If  chrysophanic  acid  urine  is  added  in  this  manner,  the  blue  of 
the  alkaline  copper  solution  is  turned  to  a  reddish-brown,  occasion^ 
ally  a  purple  color. 
The  usual  reaction  is  the  following  : 
Upon  first  addition  of  the  urine,  the  blue  color  is  changed  to  pur- 
ple, gradually  turning  reddish-brown  upon  the  further  addition  of 
the  urine. 
The  amount  of  the  principle  present  influences  the  reaction  to  a 
considerable  degree,  however. 
(4)  The  bismuth  tests.— Boettger's  and  Nylander's  alkaline  bis- 
muth tests,  when  applied  to  chrysophanic  urine,  respond  in  a  man- 
ner somewhat  similar  to  glucose. 
On  boiling  such  urine  with  the  alkaline  bismuth  mixture  of 
Boettger,  it  assumes  a  purple  color,  while  the  precipitated  bismuth 
salt  will  be  blackish-gray. 
A  similar  result  takes  place,  according  to  Salkowski,  in  Nylander's 
modification,  a  blue-black  precipitate  being  formed. 
(5)  Sachse's  solution  is  used  for  the  quantitative  estimation  of 
glucose. 
It  consists  of  solution  of  potassium  iodohydrargyrate,  with  a  con- 
siderable excess  of  alkali. 
The  solution  is  reduced  to  metallic  mercury  in  the  presence  of 
glucose. 
