256 
Nitrogen  in  Gums. 
j  Am.  Jour.  Pharm. 
I       June,  1905. 
The  sodium  was  first  heated,  then  the  gum-enzyme  slowly  heated 
so  that  the  gases  would  pass  over  the  glowing  sodium.  This  test 
was  repeated  in  the  same  manner,  except  that  the  gum-enzyme  was 
first  mixed  with  dry  potassium  hydroxide.  In  another  experiment 
the  substance  was  heated  with  a  small  quantity  of  concentrated 
sulphuric  acid  until  a  dry  charred  mass  was  obtained,  then  mixed  with 
metallic  iron  and  sodium  and  ignited,  and  finally  tested  for  cyanide. 
In  another  experiment  a  modification  of  the  Kjeldahl  quantitative 
method  was  tried.  The  gum-enzyme  was  heated  with  concentrated 
sulphuric  acid  and  a  little  mercuric  oxide  until  a  colorless  solution 
was  obtained.  The  solution  was  then  mixed  with  an  excess  of 
potassium  hydroxide  and  distilled.  The  distillate  was  passed 
through  a  tube  containing  a  piece  of  red  litmus  paper  into  a  mix- 
ture of  chloroform,  alcohol  and  potassium  hydroxide  to  convert  the 
ammonia  into  cyanide.  The  litmus  paper  remained  red  throughout 
distillation.  All  attempts  to  convert  the  nitrogen  into  cyanide 
failed. 
Another  test  for  nitrogen,  which  is  considered  less  reliable  than 
the  Lassaigne  test,  is  to  convert  the  nitrogen  into  ammonia  by 
heating  the  substance  in  a  tube  with  soda-lime  or  potassium 
hydroxide.  This  test  was  applied  to  the  gum-enzyme  when  the  red 
litmus  paper  placed  over  the  end  of  the  tube  rapidly  changed  to 
blue,  but  no  odor  of  ammonia  could  be  detected.  The  paper  was 
evenly  colored  as  if  produced  by  some  gaseous  substance.  The 
test  was  repeated  with  a  pledget  of  cotton  inserted  in  the  tube  be- 
low the  paper  to  prevent  the  possibility  of  potassium  hydroxide 
being  mechanically  carried  to  the  litmus  paper.  The  result  was 
the  same  as  in  the  previous  test.  A  blank  test  was  next  made 
under  exactly  the  same  conditions,  but  with  negative  results. 
These  experiments  indicated  the  presence  of  a  volatile  base.  Pro- 
fessor Tschirch  thought  the  odor  similar  to  pyrrol.  I,  therefore, 
repeated  the  test,  placing  in  the  top  of  the  tube  a  pine  shaving 
moistened  with  hydrochloric  acid.  This  was  rapidly  colored  red, 
thus  strongly  indicating,  if  not  conclusively  proving,  the  presence 
of  pyrrol,  or  a  pyrrol  derivative.  This  was  further  confirmed  by 
placing  5  grammes  each  of  powdered  potassium  hydroxide  and  the 
gum-enzyme  in  a  flask  and  distilling.  The  vapors  were  passed  through 
a  condenser  connected  with  a  dry  flask,  and  this  again  connected 
with  a  second  by  means  of  a  tube  passing  to  the  bottom  of  the  flask 
