GROUND  FLAXSEED. 
211 
alcohol  until  the  liquid  passes  with  little  color  or  odor.  Evapo- 
rate this  tincture  to  a  syrupy  consistence,  add  it  to  the  other 
liquid,  and  when  the  mixed  extract  has  acquired  the  consistence 
of  thick  honey  whilst  hot,  add  it  to  the  plaster  and  Burgundy 
pitch  previously  melted  together  in  a  suitable  vessel,  and  stir 
them  until  a  portion,  on  cooling,  has  the  proper  consistence. 
This  plaster  is  apt  to  be  a  little  too  soft  at  first,  owing,  appa- 
rently, to  the  absence  of  the  insoluble  portion  of  the  opium,  but 
it  soon  attains  the  proper  consistence  if  the  lead  plaster  used 
has  been  free  from  undecomposed  oil  which  appears  to  keep 
the  plaster  too  soft.  The  use  of  such  lead  plaster  and  that  which 
contains  glycerin  should  be  avoided  in  making  this  plaster. 
GROUND  FLAXSEED. 
By  Charles  V.  Hagner. 
There  are  wrong  impressions  prevailing  among  some  apothe- 
caries on  the  subject  of  "  Ground  Flaxseed."  Long  experience 
has  convinced  me  that  the  perfection  of  grinding  flaxseed  is  to 
grind  it  dry,  that  is,  without  "  raising  "  the  oil,  which  can  only 
be  done  on  a  pair  of  horizontal  mill-stones,  sharp  and  »  dressed  " 
for  that  especial  purpose.  This  process  is  a  cutting  (if  I  may 
so  term  it)  of  the  seed  into  particles,  the  stones  never  coming 
into  contact;  if  they  did,  it  would  be  a  "rubbing"  process, 
mashing  a  small  portion  of  the  seed,  at  the  same  time  squeezing 
out  the  oil,  which  would  so  grease  the  remainder  and  the  sur- 
face of  the  stones  as  to  make  any  further  grinding  of  it  imprac- 
ticable. I  suppose  the  same  thing  would  occur  if  you  put  flax- 
seed into  a  mortar  and  rubbed  it,  you  would  mash  a  portion  of  it, 
"  raise  "  the  oil,  and  so  grease  the  remainder  and  the  pestle 
and  mortar  that  all  rubbing  would  be  in  vain. 
The  common  and  most  expeditious  way  of  grinding  flaxseed 
is  by  means  of  iron  rollers ;  this  is  the  method  pursued  in  the 
oil  mills,  where  "raising"  the  oil  is  no  detriment.  This  is  a 
mashing  and  rubbing  process,  one  roller  being  larger  in  diame- 
ter, or  running  at  a  greater  speed  than  the  other ;  this  process 
"raises  "  the  oil  and  gives  the  article  a  greasy  appearance.  It 
is  a  mistake  to  suppose  that  this  is  an  evidence  of  its  purity,  or, 
because  of  its  being  dry,  that  it  is  adulterated  or  the  oil  taken 
