46  LIQUOR  OPII  COMPOSITUS. 
willing  to  pay  a  liberal  profit  upon  these  as  invested  in  it,  of 
course  should  not  make  or  use  it, — and  will  not,  no  matter  what 
might  be  said  in  attempted  justification  of  the  cost.  Upon  an 
average  it  will  represent  about  one-tenth  of  its  weight  of  pow- 
dered opium ;  and  it  will  not  remunerate  the  maker  unless  it 
yields  him  about  two  and  a  half  or  three  times  the  cost  of  that 
proportion  of  the  best  powdered  opium. 
It  happens  that  the  useful  constituents  of  opium  are  all  solu- 
ble in  both  water  and  alcohol,  and  are  insoluble  in  ether  ;  whilst 
a  very  large  portion  of  the  useless  and  hurtful  constituents  are 
insoluble  either  in  water  or  in  alcohol,  or  when  soluble  in  both 
are  also  soluble  in  ether.  Taking  advantage  of  these  circum- 
stances the  opium  is  subjected  to  the  action  of  these  solvents 
in  succession,  the  successive  residues  being  rejected,  and  the  re- 
sulting extract  is  diluted  to  form  the  depurated  solution.  A 
small  portion  of  this  is  assayed,  and  the  result  of  the  assay  is 
applied,  by  multiplication  to  the  whole,  and  this  is  then  diluted 
to  a  definite  degree  by  the  addition  of  the  other  ingredients  and 
water.  Merely  to  state  this  general  plan  or  outline  of  the  pro- 
cess without  the  detail  necessary  to  put  it  in  practice  would  be 
of  no  use,  and  would  really  defeat  the  object  of  this  paper, 
since  that  object  is  not  more  to  convince  the  reader  of  the  ne- 
cessity for  such  a  preparation,  than  to  teach  him  a  good  practi- 
cal way  of  making  it  for  himself,  and  perhaps,  also,  to  ofi'er  what 
may  be  a  useful  lesson  in  practical  pharmacy.  Beside,where  broad 
and  apparently  exaggerated  statements  are  made  in  any  particu- 
lar interest  there  is  always  room  for  suspicion  of  advertising  ;  and 
the  cause  for  suspicion  is  strengthened  when  any  reserve  can  be  de- 
tected, or  when  any  link  or  point  is  missing  in  what  should  be 
clear  inductive  detail.  It  oftens  happens  to  the  writer,  in  read- 
ing what  at  first  sight  appears  to  be  a  plain  open  and  sufficient 
detail  of  a  process,  to  have  his  suspicion  aroused  by  a  missing 
link  or  an  ambiguous  sentence,  and  therefore  the  casual  reader 
must  excuse  any  prolixity  in  detail  that  may  appear  unnecessary 
in  giving  the  following  formula  and  process,  since  this  prolixity, 
at  least,  is  not  caused  by  having  something  to  conceal. 
In  giving  the  formula  and  process  in  the  U.  S.  P.  officinal 
weights  and  measures,  nearly  or  practically  accurate  equivalents 
