A October "i9i57n"}     Examination  of  Opium  Alkaloids.  459 
powder  or  in  small  monoclinic  plates,  or  in  prisms;  odorless  and 
having  a  bitter  taste;  permanent* in  the  air. 
Papaverine  hydrochloride  is  sparingly  soluble  in  water;  soluble 
in  alcohol ;  very  soluble  in  chloroform ;  insoluble  in  ether. 
An  aqueous  solution  of  papaverine  hydrochloride  has  an  acid 
reaction  toward  litmus  paper  and  is  optically  inactive. 
If  added  to  an  aqueous  solution  of  papaverine  hydrochloride, 
silver  nitrate  solution  should  produce  a  white,  curdy  precipitate 
which  is  insoluble  in  nitric  acid. 
If  about  0.01  Gm.  of  papaverine  hydrochloride  be  dissolved  in 
5  Cc.  of  water  and  a  few  drops  of  cadmium-potassium  iodide  solu- 
tion added,  a  dense,  white  precipitate  should  be  produced. 
If  about  0.01  Gm.  of  papaverine  hydrochloride  be  dissolved  in 
1  Cc.  of  hot  alcohol,  0.5  Cc.  of  tincture  of  iodine  added,  the  mixture 
shaken  and  allowed  to  stand,  reddish-brown,  crystalline  needles  of 
papaverine  periodide  should  gradually  appear. 
If  about  0.01  Gm.  of  papaverine  hydrochloride  be  dissolved  in 
10  Cc.  of  water  and  a  few  drops  of  potassium  ferricyanide  solu- 
tion added,  a  lemon-yellow  precipitate  of  papaverine  ferricyanide 
should  form  at  once  (distinction  from  the  salts  of  other  opium  al- 
kaloids) . 
If  about  0.01  Gm.  of  papaverine  hydrochloride  be  dissolved  in 
10  Cc.  of  water  and  a  few  drops  of  a  25  per  cent,  solution  of  sodium 
acetate  added,  a  white  precipitate  should  be  produced  at  once  (dis- 
tinction from  the  salts  of  many  other  opium  alkaloids). 
If  about  0.1  Gm.  of  papaverine  hydrochloride  be  dissolved  in  a 
hot  solution  of  0:04  Gm.  of  oxalic  acid  in  5  Cc.  of  water,  the  solu- 
tion cooled  and  agitated  for  some  time,  small,  short,  opaque,  prisms 
of  papaverine  acid  oxalate  should  form  after  standing  (distinction 
from  the  salts  of  other  opium  alkaloids). 
If  about  0.01  Gm.  of  papaverine  hydrochloride  be  dissolved  in 
5  Cc.  of  water  and  a  few  drops  of  platinum  chloride  solution  added, 
a  pale  yellow,  amorphous  precipitate  should  immediately  be  produced. 
This  soon  crystallizes  into  lance-shaped  prisms,  many  of  which  are 
arranged  in  rosettes  and  tree-like  forms  (distinction  from  the  salts 
of  other  opium  alkaloids). 
If  about  0.01  Gm.  of  papaverine  hydrochloride  be  dissolved  in 
0.1  Cc.  of  sulphuric  acid  in  which  a  trace  of  iodic  acid  has  previously 
been  dissolved,  a  purple  color  should  be  produced  which  almost 
immediately  becomes  streaked  with  brown. 
