44 
LIQUOR  OPII  COMPOSITUS. 
ing  and  powdering  process.  Beside,  it  is  only  by  drying  and 
powdering  that  a  homegeneous  product  is  obtained,  every  part  of 
each  package  of  which  represents  the  whole.  If  a  physician  or 
pharmacist  buys  a  pound  of  powdered  opium,  the  assaying  of 
150  grains  or  so  of  this  will  indicate  the  quality  of  the  whole. 
But  if  he  buys  a  lump  of  crude  opium  and  assays  any  part,  or 
even  two  or  three  parts  of  it,  the  assay  may  not,  and  in  all 
probability  will  not,  represent  the  whole.  He  may  make  the 
whole  lump  into  a  strong  tincture  or  solution  by  extracting  it, 
and  assay  a  portion  of  this  solution  or  tincture,  with  the  same 
ultimate  result,  but  the  assay  is  then  less  simple  and  more 
difficult. 
This  then  is  the  chief,  though  not  the  only  merit  claimed  for 
this  liquor  opii  compositus,  that  it  is  made  by  assay,  and  there- 
fore of  practically  uniform  strength,  entirely  independent  of  the 
quality  of  the  opium  from  which  it  is  made. 
This  process  of  assay  is  not  a  highly  critical  scientific  process 
which  gives  account  of  every  tenth,  or  even  every  quarter  of  a 
per  cent,  of  the  useful  alkaloids  contained  in  the  opium,  but  the 
aim  is  simply  to  come  within  one  per  cent.,  or  thereabout,  of  the 
medicinal  value  and  efficacy  of  different  parcels  of  opium  in  its 
power  to  produce  sedation,  and  to  relieve  pain  in  disease.  Whilst 
a  critical  morphiometrical  assay,  or  an  analysis  of  opium,  is  one 
of  the  most  difficult  processes  within  the  writer's  knowledge,  and 
probably  has  never  been  once  attained  in  his  thirty  years'  expe- 
rience, a  practically  useful  and  sufficient  process,  by  various 
methods,  is  so  simple  and  easy  as  to  be  within  the  capacity  of 
any  person  who  is  at  all  fit  to  be  trusted  with  the  handling  of 
potent  agents  in  their  application  to  medicine.  The  first  steps 
of  that  simple  process  of  assay  which  is  preferred  by  the  writer 
are  those  by  which  the  solution  of  opium  which  characterizes  this 
liquor  opii  compositus  is  depurated,  or  freed  from  extraneous 
matters,  whether  these  be  hurtful  or  simply  useless.  And  this 
is  the  second  and  only  other  important  merit  claimed  for  the 
preparation.  By  rejecting  much  of  the  resinous,  gummy, 
nauseous,  and  otherwise  hurtful  constituents  of  the  heterogeneous 
mixture  called  opium,  a  real  practical  advantage  is  obtained  ; 
whilst  the  retaining  the  useful  alkaloids  in  their  natural  combi- 
