^'"May'iS2';™'}  OpiuM  Assay.  245 
opium  are  at  best  only  close  approximations,  though  sufficient  for  prac- 
tical purposes. 
About  every  tenth  lump  of  a  case  should  be  sampled  by  cutting  out 
a  cone-shaped  piece  from  the  middle  of  the  lump,  with  an  ordinary 
pocket  knife.  Then  from  the  side  of  each  cone  a  small  strip  is  taken 
from  point  to  base,  not  exceeding  say  half  a  gram  from  cones  which 
would  average  10  to  15  grams,  and  the  cone  is  then  returned  to  its 
place  in  the  lump.  The  little  strips  are  then  worked  into  a  homogen- 
eous mass  by  the  fingers,  and  the  mass  is  then  wrapped  in  tin-foil, 
moist  cloth  or  paper,  to  prevent  drying,  until  it  can  be  weighed  off  for 
>assay.  When  opened  to  be  weighed  off,  it  is  best  to  weigh  at  once  three 
portions  of  ten  grams  each.  In  one  portion  the  moisture  is  deter- 
Jiiined  by  drying  it  on  a  tared  capsule  until  it  ceases  to  loose  weight  at 
100°C.  =  212°  F.  Another  portion  is  used  for  immediate  assay,  and 
the  third  is  reserved  for  a  check  assay  if  desirable. 
Put  the  weighed  portion  into  a  flask  or  common  wide-mouthed  vial 
of  120  cc.  —  4  fluidounces  capacity,  tared  and  fitted  with  a  good  cork. 
Add  100  cc.  =  3'3  fluidounces  of  water, — distilled  water  by  preference, 
but  this  is  essential  only  when  common  water  contains  an  unusual 
amount  of  inorganic  matter — and  shake  well.  Allow  it  to  macerate 
over  night,  or  for  about  12  hours,  with  occasional  shaking,  and  then 
;shake  well  and  transfer  the  magma  to  a  filter  of  about  10  centimeters 
—  4  inches  diameter,  which  has  been  placed  in  a  funnel  and  well  wet- 
ted. As  it  is  the  shaking  which  accomplishes  the  object  here  in  view, 
rather  than  the  standing,  the  time  of  maceration  can  be  easily  short- 
•ened  even  to  three  hours,  if  the  shaking  be  frequent  and  active. 
As  rare  exceptions,  some  powdered*  opiums  will  be  found  which 
through  natural  conditions  give  a  magma  with  water  which  will  not 
filter,  or  filter  so  very  slowly  that  the  water  solvent  becomes  impracti- 
cable. When  this  is  discovered,  the  magma  is  thrown  away  and  a  fresh 
portion  of  powder  is  taken.  Wash  this  by  agitation  in  the  bottle  with 
,30  cc.  =  1  fluidounce  of  ether  (s.  g.  '728),  transfer  it  to  a  filter,  rinse 
the  bottle  with  20  cc.  =  '66  fluidounce  more  ether,  and  pour  this  into 
the  opium  in  the  filter.  When  this  has  passed  through,  wash  the  filter 
and  opium  with  10  cc.  —  '33  fluidounce  more  ether  applied  drop  by 
drop  around  the  edges  of  the  filter  and  on  the  surface  of  the  opium. 
Then  dry  the  powder  on  the  filter  and  use  it  as  in  the  case  of  opium 
which  does  not  need  to  be  first  washed  with  ether. 
Opium  which  is  adulterated,  or  standardized  by  admixture  with  dex- 
trin, gums,  sugar  or  glucosides,  yields  an  impracticable  magma  with 
water,  and  ether  washing  to  such  does  little  or  no  good.  All  such 
•.samj)les  have  to  be  exhausted  with  an  alcoholic  solvent.  If  not  much 
adulterated  a  mixture  of  equal  measures  of  alcohol  (s.  g.  '820)  and 
water  will  answer  best,  but  generally  a  mixture  of  two  measures  of 
