414  Reactions  of  A  Ikaloids.  { ^™T;£^Tm' 
REACTIONS  OF  HYDRASTINE  AND  OTHER 
ALKALOIDS.1 
By  D.  Vitali. 
If  a  small  crystal  of  hydrastine,  or  of  one  of  its  salts,  is  placed  on 
a  porcelain  capsule  and  covered  with  concentrated  sulphuric  acid 
(0-5-1  Cc.Wt  turns  yellow,  and,  on  stirring,  the  liquid  acquires  the 
same  color ;  on  adding  a  small  fragment  of  nitre  (an  excess  must  be 
avoided),  the  color  changes  to  a  more  or  less  intense  brownish- 
yellow  ;  if  a  solution  of  stannous  chloride  is  now  added  drop  by 
drop,  the  solution  acquires  a  magnificent  reddish  violet  color,  the 
intensity  of  which  depends  on  the  amount  of  alkaloid  present.  This 
coloration  is  not  destroyed  on  dilution  with  water. 
If  a  particle  of  hydrastine  is  treated  with  nitric  acid  (4  to  6  drops), 
the  alkaloid  turns  yellow,  on  heating  for  an  instant  to  the  boiling 
point,  nitrous  fumes  are  evolved,  and,  on  evaporating  to  dryness  at 
a  gentle  heat,  a  yellowish  residue  is  left,  which,  when  cold,  is  colored 
brownish-yellow  by  alcoholic  potash,  and  remains  as  a  greenish-brown 
mass  on  evaporating  the  alcohol.  When  cold,  this  becomes  deep- 
violet  on  treatment  with  sulphuric  acid.  Solutions  of  hydrastine 
must  be  evaporated  to  dryness  before  applying  the  tests,  which  are 
sufficiently  delicate  to  detect  0  0001  gram  of  the  alkaloid. 
Bebeerine  turns  blood-red  on  treatment  as  described  with  concen- 
trated sulphuric  acid  and  nitre,  the  color  changing  to  green  on  the 
addition  of  stannous  chloride. 
Codeine  turns  dark  brick-red  when  alcoholic  potash  is  added  to 
its  solution  after  treatment  with  nitric  acid,  and  coffee-colored 
when  further  treated  with  sulphuric  acid;  similarly,  narcotine 
acquires  an  orange  color  on  the  addition  of  potash,  the  color 
changing  to  violet-red  on  adding  sulphuric  acid,  and  red  to  yellow 
on  diluting  with  water. 
A  rather  less  delicate  test  for  hydrastine  is  as  follows  :  A  particle 
of  the  solid  alkaloid  is  fused  with  five  or  six  times  its  weight  of 
caustic  potash,  the  melt  allowed  to  cool,  acidified  with  hydrochloric 
acid,  extracted  with  chloroform,  the  extract  evaporated  to  dryness 
on  the  water-bath,  and  the  residue  treated  with  a  very  dilute  solu- 
tion of  ferric  chloride ;  a  fine,  blue  coloration  is  obtained  if  a  few 
milligrams  of  the  alkaloid  has  been  employed  ;  the  color  is  destroyed 
by  acids,  and  changed  to  brownish-red  by  alkalies. 
1  VOrosi,  14,  405-416;  Jour.  Chem.  Soc,  June,  1892,  755. 
