Am.  Jour.  Pliarni.  > 
March,  1886.  J 
The  Tests  for  Atropine. 
131 
The  reactions  just  alluded  to  may  as  well  be  used  in  the  identifica- 
tion of  atropine.  I  have  modified  and  completed  the  other  tests  for 
the  said  alkaloid  in  the  following  way: 
I.  One  milligram  of  atropine  and  about  the  same  quantity  of 
nitrate  of  sodium  are  rubbed  together  by  means  of  a  glass  rod,  the 
top  of  which  is  to  be  moistened  with  very  little  sulphuric  acid  (1*84 
sp.  gr.);  this  may  best  be  performed  on  a  porcelain  dish  or  slab. 
Then  a  little  sodium  hydrate  is  rubbed  in  a  mortar  with  absolute 
alcohol,  so  as  to  form  a  saturated  solution.  If  this  is  poured  drop  by 
drop  on  the  oxidized  alkaloid,  a  red  or  violet  color  is  developed. 
II.  Nitrite  of  sodium,  instead  of  nitrate,  applied  in  the  same  way 
as  above,  yields  an  orange  mixture,  turning  red,  violet,  or  lilac,  if  it  is 
gradually  diluted  by  an  aqueous  solution  of  hydrate  of  sodium,  about 
1*160  sp.  gr. ;  the  caustic  lye  is  to  be  added  in  excess. 
III.  Atropine  may  be  heated  to  the  boiling  point  in  a  mixture  of 
one  volume  of  glacial  acetic  acid  and  one  volume  sulphuric  acid  (1*84 
sp.  gr.)  without  any  coloration.  At  last  the  boiling  liquid  begins  to 
display  a  well  marked  green-yellowish  fluorescence.  After  cooling, 
the  liquid  evolves  the  odor  of  acetic  acid,  but  besides  a  very  pleasant 
aromatic  smell  is  distinctly  perceptible. 
I  may  add,  moreover,  that  hyoscyamine  as  well  as  homatropine 
show  the  same  behavior  as  atropine  with  regard  to  phenolphtalem. 
The  most  conclusive  way  for  demonstrating  this  fact  is  to  place  one 
milligram,  or  even  much  less,  of  the  alkaloid  on  phenolphtalem 
paper.  Then  add  one  drop  of  alcohol,  0*81  sp.  gr.  or  absolute;  no 
coloration  at  all  will  be  noticed.  Allow  the  alcohol  to  evaporate  and 
then  touch  the  alkaloid  with  a  drop  of  water.  Now  the  brilliant  red 
coloration  will  immediately  make  its  appearance;  it  disappears  as  soon 
as  alcohol  is  again  applied,  and  reappears  when  the  latter  is  allowed 
to  evaporate. 
Dr.  Schweissinger  stated  homatropine  to  be  devoid  of  action  on 
mercuric  chloride.  In  my  experiments,  however,  I  ascertained  that  it 
perfectly  agrees  in  that  respect  with  atropine,  whereas  hyoscyamine  did 
not  yield  a  precipitate  in  the  solution  of  mercuric  chloride. 
Lastly,  I  thought  it  interesting  enough  to  try  also  cocaine.  The 
alkaloid  produces  a  blue  coloration  on  litmus  paper  if  moistened  with 
either  water  or  alcohol,  but  it  does  not  partake  of  the  power  of  red- 
dening phenolphtalem  paper.  •  As  to  mercuric  chloride,  cocaine  im- 
mediately affords  a  very  abundant  purely  white  precipitate.    But  it 
