LIQUOR  OPII  OOMPOSITUS.  51 
grains  or  100  grammes,  or  the  original  weight  of  the  opium,  and 
warm  it  in  the  water  bath  until  the  extract  is  completely  dis- 
solved.   Then  pour  this  solution  into  an  eight  ounce  bottle,  and 
rinse  the  still  with  a  few  drops  of  water,  adding  the  rinsing  to 
the  contents  of  the  bottle.    When  the  bottle  and  contents  are 
cold  pour  on  to  the  diluted  extract  3  f^.  or  90  cc.  of  stronger 
ether,  stop  the  bottle  well,  shake  it  vigorously,  allow  it  to  stand 
a  few  moments  till  the  ether  separates,  and  pour  this  off  as 
closely  as  is  possible  with  care.    Pour  on  3  f|.  or  90  cc.  more 
ether,  again  shake  vigorously,  and  pour  it  off  as  closely  as  possi- 
ble.   Repeat  this  washing  with  ether  a  third  time,  when  the 
accumulated  washings  will  measure  about  8  to  8*5  f^.  or  240  to 
255  cc.    Put  this  into  the  still  and  distil  it  to  dryness  in  a  water 
bath  with  great  care,  remembering  the  inflammability  of  the 
ether  vapor.    In  this  way  about  7  f^.  of  210  cc.   of  the  ether 
may  be  recovered  in  a  condition  to  be  used  again  for  the  same 
purpose.    The  residue  from  the  ether  washings  varies  very  much 
in  different  parcels  of  opium,  but  may  average  about  1  per  cent, 
of  the  weight  of  the  opium.    It  is  always  a  mixture  of  dark 
oily  matter  of  a  nauseous  disagreeable  odor,  and  a  mass  of  solid 
matter  which  is  amorphous  or  crystalline  according  to  the  rate 
of  evaporation  and  the  amount  of  heat  used.    By  spontaneous 
evaporation  large  square  tabular  crystals  are  formed.    Pour  the 
diluted  extract  of  opium,  with  the  shallow  stratum  of  ether 
which  could  not  be  poured  off,  from  the  bottle  into  the  evapora- 
ting dish,  and  by  means  of  the  water  bath  evaporate  it  to  about 
one  half  its  volume.    Put  10  fg.  or  300  cc.  of  water  into 
the  cleansed  vessel  first  used  for  mixing  the  opium  and  water, 
and  pour  into  this  the  contents  of  the  evaporating  dish,  rinsing 
the  dish  with  a  little  water,  and  adding  the  rinsing  to  the  larger 
portion.    This  dilution  produces  another  insoluble  precipitate, 
but  one  which  is  loose  and  flocculent  and  easily  washed  on  a 
filter.    At  this  point  it  is  necessary  to  decide  whether  the  solu- 
tion is  to  be  made  up  or  finished  by  weight  or  by  measure, 
though  it  may  be  done  by  both,  the  weight  answering  as  a  check 
upon  the  measure,  and  vice  versa.    As  it  is  always  given  by 
measure,  (drops  or  minims)  and  has  its  formula  constructed  upon 
minims  or  volume ; — and  as  different  parcels  of  opium  yield  the 
