206  Atropine  and  the  Mydriatic  Alkaloids. 
Mix  the  spirit  with  the  water  and  dissolve  the  extract  in  the  mix- 
ture. One  fluidounce  of  this  tincture  will  contain  one  grain  of  total 
alkaloid. 
In  concluding  this  the  last  part  of  the  report,  we  wish  to  gratefully 
acknowledge  the  valuable  assistance  which  we  have  from  time  to  time 
received  from  Professor  Redwood,  who  has  closely  followed  the  progress 
of  the  investigation,  and  made  many  fruitful  suggestions  which  have 
contributed  to  its  successful  result;  We  also  wish  again  to  thank  Pro- 
fessor Attfield  for  having  allowed  the  work  to  be  carried  on  in  the 
Laboratories  of  the  Pharmaceutical  Society.  The  investigation  has 
been  largely  aided  by  a  grant  from  the  Research  Fund  of  the  British 
Pharmaceutical  Conference. — Pharm.  Jour.  Trans.,  February  9,  1884. 
A  NEW  REACTION  AND  TEST  FOR  ATROPINE  AND 
THE  MYDRIATIC  ALKALOIDS.1 
By  A.  AY.  Gereaed,  F.C.S., 
Teacher  of  Pharmacy  to  University  College. 
Whilst  studying  the  behavior  of  atropine  towards  mercuric  chloride 
I  was  somewhat  surprised  to  find  on  mixing  hot  alcoholic. solutions 
that  they  gave  a  yellow  precipitate,  which  on  boiling  became  red.  On 
diluting  the  mixture  with  water  a  further  amount  of  yellow  precipitate 
was  obtained,  which  also  changed  to  red  on  boiling. 
The  precipitate  separated,  washed  and  dried,  was  found  on  analysis 
to  be  mercuric  oxide,  with  a  small  trace  of  mercurous  oxide. 
The  reaction  representing  the  first  change  can  be  shown  by  the  fol- 
lowing equation  : 
2C17H2SN03+H20+HgCla=2CirH23N08HCl+HgO. 
In  addition  to  the  above  reaction,  I  find  that  a  second  one  takes 
place  simultaneously.  This  second  reaction  is  between  the  atropine 
hydrochlorate  and  two  more  molecules  of  the  mercuric  salt  yielding 
the  following  combination : 
C17H23N03HC1    +    2HgCl2=  C17H23N03HCl(HgCl2)2 
Atropine  hydrochlorate.      Mercuric  chloride.    Dimercuric  chloride  atropine 
hydrochlorate. 
On  cooling  and  setting  aside  a  few  hours  this  compound  separated 
in  tufts  of  crystalline  plates. 
1  Read  at  an  Evening  Meeting  of  the  Pharmaceutical  Society,  March  5, 
1884. 
f  Am.  Jour.  Pharm. 
\       April,  1884. 
