454 
Estimation  of  Formaldehyde, 
(Am.  Jour.  Pharm. 
\     October,  1913. 
The  test  is  usually  conducted  as  follows :  About  2  c.c.  of  urine 
specimen,  contained  in  five-inch  test  tube,  is  warmed  and  two  drops 
of  one-half  per  cent,  solution  of  phenylhydrazine  hydrochloride  is 
added,  followed  by  two  drops  of  one-half  per  cent,  solution  of 
sodium  nitroprusside,  the  mixture  being  made  strongly  alkaline  with 
saturated  solution  of  sodium  hydroxide.  In  strengths  1-20,000  to 
1-50,000,  a  deep  blue  coloration  results,  changing  in  a  few  minutes 
to  green,  then  yellow,  or  perhaps,  red.  In  more  dilute  solutions 
the  blue  lasts  momentarily  only,  and  is  quickly  superseded  by  green. 
The  blue  may  be  made  to  last  longer  and  become  more  distinct 
by  adjustment  of  the  quantities  of  sodium  nitroprusside  and 
phenylhydrazine  hydrochloride  added,  the  weaker  strengths  re- 
quiring less  nitroprusside  and  phenylhydrazine.  In  alkaline  solu- 
tions phenylhydrazine  gives  yellow  color,  therefore,  if  there  is  but 
a  trace  of  formaldehyde,  the  depth  of  blue  color  is  masked  and 
converted  into  green  by  mixtures  of  colors  blue  and  yellow. 
Phloroglucin  test,  the  author  of  which  I  have  lost  record,  is 
quite  satisfactory  for  dilutions  of  formaldehyde  in  urine,  not  ex- 
ceeding 1-100,000,  the  red  color  being  masked  by  yellow  of  the  urine. 
The  author  of  this  test  directs  that  a  solution  of  phloroglucin,  1 
gram,  alcohol  90  per  cent.  100  c.c.  and  sodium  hydroxide  10  grams, 
be  made  fresh.  A  much  better  plan  is  to  prepare  a  solution  of 
phloroglucin  in  alcohol,  1  gram  to  100  c.c,  and  add  strong  solution 
of  sodium  hydroxide  to  specimen  at  time  of  testing. 
The  test  is  conducted  as  follows :  To  2  c.c.  of  specimen,  previ- 
ously warmed,  contained  in  a  five-inch  test  tube,  add  one  drop 
of  alcoholic  solution  of  phloroglucin,  then  make  strongly  alkaline 
with  saturated  solution  of  sodium  hydroxide,  previously  warmed, 
the  color  produced  is  red. 
These  tests  have  been  used  with  satisfaction  in  connection 
with  an  investigation  made  by  Dr.  Burnam  and  his  associates.  It 
seems  to  me  desirable,  in  connection  with  this  paper,  to  call  at- 
tention to  the  character  of  Dr.  Burnam's  work  and  the  importance 
of  the  conclusion  arrived  at.  In  a  few  words,  Dr.  Burnam  has 
learned  that  small  doses,  as  little  as  five  grains  per  day  of  hexa- 
methylenamine  may  produce  formaldehyde  in  the  urine  of  strength 
exceeding  1-30,000,  this  being  highly  destructive  to  the  mucosa  of 
the  bladder,  while  in  other  patients  or,  perhaps,  at  different  times, 
one  hundred  grains  per  day  will  produce  only  traces-  of  formalde- 
hyde, or  perhaps,  none  at  all.    The  point  of  interest  is  that  it  is 
