Am^Joiir^Pharm.  j        Atropine  and  the  Mydriatic  Alkaloids.  207 
It  is  seen  in  the  first  equation  that  water  is  essential  to  the  produc- 
tion of  the  mercuric  oxide,  this  I  have  proved  by  mixing  absolute 
alcoholic  solutions,  also  ethereal  solutions  of  the  two  salts,  but  no 
reaction  took  place  until  water  was  added.  As  commercial  alcohol 
contains  traces  of  water  a  slight  reaction  may  follow  its  use.  The 
above  experiment  was  repeated  on  hyoscyamine,  daturine,  duboisine, 
and  homatropine,  with  the  same  result,  thus  affording  additional  proof 
of  the  unity  of  the  mydriatic  alkaloids. 
The  composition  of  the  above  doable  salt  was  established  as  follows  : 
500  milligrammes  of  the  carefully  dried  salt  were  dissolved  in  water, 
and  potassic  hydrate  added  in  slight  excess ;  the  resulting  precipitated 
mercuric  oxide  was  separated,  dried  and  weighed,  then  calculated  as 
Hg;  it  gave  228  milligrammes  or  45*6  per  cent.  The  filtered  solution 
and  washings  from  the  mercuric  oxide  were  faintly  acidified  with 
acetic  acid,  and  the  chlorine  estimated  writh  argentic  nitrate,  using 
potassic  chromate  as  indicator ;  I  thus  obtained  99'4  CI  or  19*9  per  cent. 
The  difference  of  the  above  quantities  being  assumed  as  atropine  would 
leave  34*5  percent,  for  that  body,  so  that  analysis  and  formula  percent- 
ages may  be  thus  compared  : 
Percentages.  Percentages. 
Theory.  Found. 
Mercury   46'1  45*6 
Chlorine   20'4  199 
Atropine   333  34-5 
To  further  prove  these  results  another  analysis  was  made  as  follows  : 
500  milligrammes  of  the  salt  were  dissolved  in  water,  and  treated 
with  H2S  in  excess,  and  the  precipitated  mercuric  sulphide  washed, 
dried  and  weighed  gave  mercury  equalling  45*9  per  cent.  The  filtrate 
and  washings  were  warmed  for  some  time  until  quite  free  from  H2S ; 
it  was  then  made  neutral  with  potassic  hydrate  and  the  chlorine  esti- 
mated as  above.  I  now  obtained  20*7  per  cent.  CI.  This  result  thus 
confirms  the  previous  analysis. 
In  addition  to  the  foregoing,  I  have  prepared  hydrochlorate  of 
atropine,  and  treated  it  with  two  molecules  of  HgCl2,  and  thus  obtained 
the  same  double  compound. 
Expecting  to  find  other  alkaloids  to  react  in  a  similar  manner,  the 
same  test  was  applied  to  as  many  alkaloids  as  were  at  my  disposal  ;  in 
no  case  did  I  obtain  a  red  precipitate.  The  following  were  examined  : 
— Strychnia,  brucia,  morphia,  codeia,  veratria,  aconitia,conia,gelseminia, 
caifeia,  theia,  cinchonia,  cinchonidia,  quinis  ami  quinidia.    With  most 
