LIQUOR  OPII  COMPOSITUS. 
125 
by  the  alcohol,  when  collected  and  dried,  weigh  about  14  per 
cent,  of  the  opium,  or  about  31  per  cent,  of  the  dry  watery 
extract.  The  alcohol  may  be  recovered  from  the  tincture  by 
distillation,  if  operating  with  quantities  that  will  warrant  it,  oth- 
erwise it  may  be  driven  off  by  rapid  evaporation  and  boiling  till 
the  required  weight  is  obtained.  This  residue  is  again  in  the 
form  of  a  thin  extract,  and  should  be  poured  while  warm  into  a 
bottle,  because,  while  warm,  less  of  it  will  adhere  to  the  evapora- 
ting vessel.  It  is  then  to  be  cooled  before  adding  the  first  por- 
tion of  ether,  and  the  ether  i3  first  washed  round  the  evaporating 
vessel  for  the  purpose  of  washing  the  small  portion  that  adheres 
to  it.  The  ether  commonly  becomes  only  slightly  colored,  but 
in  the  character  and  amount  of  matter  removed  by  it  varies 
very  much  in  every  instance  in  which  the  writer  has  applied  it. 
Upon  spontaneous  evaporation  this  ether  leaves  at  times  only 
a  small  portion  of  dark  colored  extractive  matter,  soluble  in 
alcohol  and  water  and  of  a  bitter  taste;  at  other  times  it  yields 
a  crystalline  crust  upon  the  vessel;  and  again  it  yields  an  oily 
matter  which  dries  only  by  prolonged  exposure,  or  rather  by  a 
process  of  oxidation.  Sometimes  the  residue  has  that  peculiar 
nauseous  odor  which  is  more  faintly  noticed  in  the  opium,  but 
at  other  times  it  is  almost  free  from  odor.  In  perhaps  two  or 
three  of  the  six  times  the  writer  has  used  the  washing  with  ether, 
it  has  appeared  to  be  of  but  little  use,  because  the  matters  re- 
moved from  it  were  so  very  trifling.  But  in  the  other  cases  it 
was  so  decidedly  useful  that  it  is  regarded  as  an  important  step 
toward  uniformity  of  result.  For  its  use  in  the  process  the 
writer  is  indebted  to  the  suggestion  of  Prof.  Procter,  who  used 
it  in  his  formula  for  a  similar  preparation,  published  in  this  Jour- 
nal some  years  ago. 
In  dissolving  the  washed  extract  in  water  much  care  is  neces- 
sary to  avoid  loss.  It  should  be  transferred  to  a  tared  vessel 
capable  of  holding  it  when  diluted,  and  all  the  vessels  well 
rinsed  with  the  water  for  dilution.  Upon  dilution  a  copious 
light  flocculent  precipitate  of  a  light  brown  color  is  thrown  down, 
which  when  separated  by  filtration  and  dried  weighs  about  1.2 
per  cent,  of  the  opium.  All  these  solutions,  from  first  to  last, 
are  strongly  acid  to  litmus  paper,  showing  probably  that  the 
bimeconate  of  morphia  has  suffered  no  decomposition  or  loss  of 
