^ctobe^wS111"}        Estimation  of  Formaldehyde.  453 
but  because  by  stimulating  interest  in  the  subject  they  may  aid  in 
the  development  of  the  profession  along  the  lines  of  the  ideals  held 
out  by  such  worthy  members  as  Galen,  Dioscorides,  Lully,  Valen- 
tine, Paracelsus,  Van  Helmont,  Glauber,  Goulard,  Scheele  and 
many  others  not  so  well  known,  but  of  equal  prominence  in  their 
time. 
DETECTION  AND  QUANTITATIVE  ESTIMATION  OF 
MINUTE  QUANTITIES  OF  FORMALDEHYDE  IN 
PRESENCE  OF  HEXAMETHYLENAMINE  AND 
METHYL  ALCOHOL  IN  PRESENCE  OF  ETHYL 
ALCOHOL.1 
By  H.  A.  B.  Dunning. 
Sometime  during  the  year  19 12,  Dr.  Curtis  F.  Burnam,  member 
of  the  staff  of  Johns  Hopkins  Hospital,  sought  my  advice  as  to  the 
most  satisfactory  method  of  detecting  traces  of  formaldehyde  in 
urine. 
After  a  careful  investigation,  I  recommended,  as  most  delicate 
and  satisfactory,  three  tests  herein  named  and .  described. 
Only  one  of  these  tests,  Rimini's,  was  of  particular  value  in  his 
work  on  account  of  the  presence  of  hexamethylenamine  in  material 
tested.  Hehner's  milk  test,  while  most  delicate,  was  not  suitable 
on  account  of  being  conducted  in  acid  solution,  resulting  in  de- 
composition of  hexamethylenamine  with  the  production  of  formal- 
dehyde. 
While  Rimini's  test  has  been  found  to  be  most  satisfactory  in 
differentiation  of  formaldehyde  in  presence  of  hexamethylenamine, 
experience  teaches  that  certain  precautions  should  be  observed  to 
obtain  best  results. 
The  specimens  to  be  examined  and  all  test  solutions  should 
be  warm,  not  hot,  and  an  excess  of  nitroprusside  solution  should  be 
avoided.  In  weak  specimens  the  nitroprusside  solution  should  be 
diluted  five  to  ten  times.  In  urine  formaldehyde  may  be  detected 
readily  by  this  test  in  strength  of  1-100,000;  in  weaker  strengths 
than  this,  much  depends  upon  the  care  and  experience  of  the 
operator. 
1  Read  at  -the  Nashville  meeting  of  the  American  Pharmaceutical  As- 
sociation, August,  1913. 
