Am.  Jour.  Pharm.  ) 
Oct.,  1877.  J 
Laboratory  Notes. 
of  that  taken.  2.  The  same  operation  was  made,  substituting  crystal- 
lized oxalic  acid  for  the  ammonium  sulphate  used  before.  ■  3.  The  sul- 
phuric acid  was  simply  evaporated  to  one-fourth  its  bulk  without  any 
addition.  Each  of  the  three  purified  samples  gave  negative  results  in 
all  u  tests  for  nitric  acid."  The  purification  with  use  of  oxalic  acid 
was  repeated  several  times  without  getting  a  perfectly  colorless  product, 
but  the  slight  brown  tint,  due  to  remaining  carbon,  was  scarcely  per- 
ceptible when  a  few  drops  were  placed  on  porcelain.  I  think  the 
purification  with  ammonium  sulphate  is  more  satisfactory,  and  suffi- 
ciently sure.  In  all  the  tests  of  morphia  parallel  operations  were  made 
with  separate  use  of  each  of  the  samples  of  purified  sulphuric  acid,  and 
the  results  were  alike  for  the  three.  The  purification  of  the  morphia  used 
in  the  tests  was  done  by  washing  a  good  sample  of  "  morphia,  pure," 
in  very  fine  powder,  on  the  filter :  first  with  chloroform  and  then  with 
ether,  each  in  repeated  portions,  and  drying. 
On  treating  the  purified  morphia  with  the  purified  sulphuric  acid  at 
ioo°C.  for  half  an  hour,  a  pink-red  color  was  in  each  case  obtained. 
The  least  quantity  of  morphia  giving  the  reaction  distinctly  was  found 
to  be  one-fifteenth  of  a  milligram  (0.000064  gram  or  one-thousandth 
of  a  grain). 
In  each  case,  after  treatment  with  the  sulphuric  acid  at  ioo°C.  for 
half  an  hour,  aod  cooling,  the  addition  of  a  drop  of  nitric  acid  gave  a 
beautiful  blue  to  violet-red  color,  soon  changing  to  an  orange  and  dark- 
red  color,  from  which  the  orange  faded  out.  This  test  (Husemann's) 
is  certainly  more  distinctive  than  the  test  by  hot  sulphuric  acid  alone, 
but  its  delicacy  is  only  a  little  greater.  In  this  investigation  the  color 
was  not  obtained  in  quite  as  small  quantities  as  those  reported  by  Huse- 
mann,  but  the  reaction  appeared  distinctly  in  each  trial  with  one- 
eighteenth  of  a  milligram  (0*000054  gram  or  one-twelvehundredth  of  a 
grain)  of  the  morphia. 
Narcotina^  with  hot  concentrated  sulphuric  acid  alone,  gave  the  same 
reactions  that  morphia  does.  In  Husemann's  test,  the  color  given  by 
narcotina  was  bright  pink-red  or  carmine,  the  limit  being  found  at  about 
one- fifteenth  milligram  of  the  alkaloid.  Codeina,  treated  with  pure 
sulphuric  acid  at  ioo°C,  gave  a  blue-purple  color.  The  addition  of 
a  drop  of  nitric  acid  (after  cooling)  caused  a  little  change,  the  color 
being  blue  to  violet-red  (coinciding  with  that  of  morphia).  Narceina 
