Am.  Jour.  Pharm.") 
March,  1884.  j 
Tests  for  Vegetable  Alkaloids. 
151 
once  deposited,  which  are  darker  in  strong  solutions,  and  when  dry 
resemble  powdered  gamboge  in  color.  With  codeine  hydrochloride,  a 
flocculent  precipitate  is  produced,  which  when  dry  resembles  the  quini- 
dine  precipitate  in  tone,  being  a  paler  yellow  than  the  morphine  pre- 
cipitate. With  narcotine,  in  concentrated  hot  solutions,  the  precipitate 
coagulates  in  resinous  masses,  which  when  dry  have  the  color  of  dry 
precipitated  ferric  hydroxide.  With  strychnine  nitrate,  the  reaction  is 
more  sensitive  than  with  all  the  other  vegetable  alkaloids,  the  strych- 
nine being  entirely  precipitated,  and  moreover  the  precipitate  is  not 
soluble  in  excess  of  the  reagent.  In  dilute  solutions  of  strychnine 
nitrate,  colorless  flocks  separate  which  become  yellowish  in  air;  in 
concentrated  solutions,  yellow  flocks  form  which  do  not  coagulate  on 
standing,  and  when  dry  are  of  a  fine  intense  deep  golden  yellow  color. 
With  brucine  nitrate,  when  the  reagent  is  added  in  successive  portions 
to  a  moderately  concentrated  solution  of  this  alkaloid  salt,  three  dis- 
tinct precipitates  are  obtained:  1.  Reddish  yellow,  which  collects  in 
resinous  masses.  2.  Light  golden  yellow  flocks.  3.  Colorless  flocks, 
which  form  a  crust  on  the  surface  of  the  liquid.  When  the  mixed 
precipitates,  are  boiled  with  water,  the  greater  part  dissolves,  leaving 
an  amorphous  deep  orange  residue.  The  solution  deposits  yellow 
■crystals  of  the  double  sulphide. 
With  atropine  sulphate  in  strong  solutions,  a  yellow  deposit  is 
formed,  which  coagulates  on  shaking  or  heating,  but  wrhen  dry  is  not 
so  dark  as  the  dry  morphine  precipitate. 
With  bebeerine  hydrochloride,  a  dark  colored  precipitate  is  formed 
which  coagulates  in  strong,  and  especially  in  hot,  solutions,  and  when 
dry  is  greyish  brown.  The  alkaloids  also  form  double  sulphides  with 
other  metallic  sulphides. 
Lead  chloride  can  be  used  as  a  reagent  for  vegetable  alkaloids ;  it 
should  be  dissolved  in  a  solution  of  sodium  chloride,  which  dissolves 
more  of  the  lead  salt  than  cold  water  does.  The  precipitates  are 
generally  crystalline,  and  consist  of  a  mixture  of  lead  chloride  and 
an  alkaloid  salt.  Quinine  and  brucine  form  crystalline  powders; 
cinchonine,  morphine,  and  codeine  small  fine  needles;  the  strychnine 
precipitate  when  dry  forms  a  crystalline  asbestos-like  felted  mass. 
The  lead  chloride  is  not  so  delicate  a  test  as  the  thioantimonate.  A 
strong  solution  of  sodium  chloride  completely  precipitates  -bebeerine 
from  its  solutions. — Jour.  Chem.  Soc,  1884,  p.  120;  Chem.  News., 
vol.  48,  p.  65. 
