Am.  Jour.  Pharaj.l 
March,  1887.  J 
New  Crystalline  Acid  in  Urine. 
133 
kapton.  Tannic  acid  is  excreted  as  gallic  acid.  All  these  products 
possess  the  property  of  reducing  alkaline  copper  solution.  Hydro- 
chinon  and  oxyphenic  acid  in  the  presence  of  an  alkali,  and  when  ex- 
posed to  the  air  absorb  oxygen,  and  turn  first  green,  then  brown,  and, 
finally  black. 
It  was  learned  that  the  person  who  voided  the  urine  under  exam- 
ination never  had  occasion  to  use  any  of  the  above-named  substances ; 
and,  therefore,  one  would  hardly  expect  to  find  the  products  of  their 
metamorphosis  in  the  urine.  It  must  not  be  forgotten,  however,  that 
oxyphenic  acid  has  several  times  been  found  in  normal  urine. 
The  peculiar  acid  in  question  is  contained  in  rather  large  quantity 
in  this  particular  urine,  nearly  one  gramme  of  the  lead  salt  having 
been  obtained  from  100  cc.  of  the  urine.  Its  reducing  power  is 
greater  than  that  of  glucose  ;  0*6  cc.  of  the  undiluted  urine  was 
sufficient  to  reduce  the  cupric  oxide  in  10  cc.  of  Fehling's  solution, 
equivalent  to  0*05  of  glucose,  or,  expressed  in  glucose  units,  equiva- 
lent to  8*3  per  cent,  of  glucose. 
Some  of  the  reactions  of  this  urine,  when  considerably  diluted  with 
water  or  with  normal  urine,  strikingly  resemble  reactions  often  noticed 
in  this  laboratory  in  urine  considered  and  acknowledged  to  be  free 
from  glucose,  especially  in  the  reaction  with  diluted  Fehling's  solu- 
tion. With  the  urine  containing  the  acid,  diluted  either  with  water  or 
with  normal  urine,  and  diluted  Fehling's  solution,  a  brownish  and 
sometimes  greenish  coloration  is  produced,  but  no  appreciable  reduc- 
tion of  the  cupric  oxide  is  observed.  A  similar  result  has  often  been 
noticed  in  this  laboratory  when  a  presumably  normal  urine  has  been 
tested  with  Fehling's  solution. 
It  is  quite  likely  that  this  acid  may  occur  more  frequently  in  urine 
than  is  suspected,  probably  only  in  less  quantity  than  contained  in  the 
urine  j  ust  referred  to,  and  to  its  presence  possibly  maybe  attributed 
the  many  peculiar  and  unsatisfactory  reactions  so  often  noticed  when 
testing  urine  with  Fehling's  solution.  Quite  likely,  too,  in  some  sam- 
ples of  urine,  the  acid  may  be  contained  in  sufficient  quantity  to  pro- 
duce a  reduction  with  Fehling's  solution  in  such  a  satisfactory  manner 
as  to  be  mistaken  for  glucose,  and  thus  many  erroneous  diagnoses  of 
diabetes  mellitus  may  have  occurred. 
The  urine  from  which  the  acid  was  obtained  was  of  a  brownish 
red  tint,  perfectly  clear  and  without  sediment. 
To  isolate  the  acid  the  following  method  was  employed  : 
