Am.  Jour.  Pharm.  \ 
January,  1896.  J 
Cotton  Seed  Oil. 
43 
so  arranged  as  to  effect  this  purpose.  The  "  relinting  "  done,  the  seed 
are  hulled  by  means  of  buhr-stones  set  in  such  position  that  the 
hull,  or  testa,  is  cracked  without  crushing  the  seed  to  any  consider- 
able extent.  The  hulls  are  then  separated  by  machinery  from  the 
internal  portion  of  the  seed,  the  endosperm,  which  is  next  passed 
between  heavy  chilled  rollers.  This  treatment  crushes  the  seed  into 
a  flat  mass  and  thereby  ruptures  the  oil  cells.  The  crushed  mass  is 
put  through  heaters,  in  which  it  is  cooked  for  fifteen  or  twenty 
minutes,  and  from  which  it  is  transferred  to  the  cake-former.  Here 
it  is  prepared  for  the  press,  and  consists  of  a  sticky  mass.  After 
the  press  boxes  have  been  filled,  hydraulic  pressure  is  applied,  usu- 
ally from  3, GOO  to  4,000  pounds  per  square  inch  of  cylinder  ram. 
After  the  expression  of  the  oil,  the  residue  is  known  as  press  cake 
and  cake  meal. 
The  entire  process,  from  the  time  the  seed  enter  the  screening 
"  boll  "  until  the  oil  is  extracted  and  the  cake  removed  from  the 
press,  occupies  about  thirty-five  to  forty  minutes. 
The  yield  of  oil  varies  with  the  locality  and  richness  of  the  soil, 
as  well  as  with  season  and  climatic  changes.  Moist  soil  affords  the 
best  yield.  In  some  of  the  excessively  dry  summers  of  the  South- 
west the  seed  do  not  contain  enough  oil  to  pay  for  its  extraction. 
The  average  yield  per  ton  of  seed  is  from  36  to  40  gallons,  or 
over  250  pounds,  of  oil.  From  1  ton  of  seed  about  30  pounds  of 
lint,  900  pounds  of  hulls  and  750  pounds  of  cake  meal  are  also 
obtained.  The  remaining  70  pounds  is  made  up  of  dirt  and  loss  in 
working. 
In  Georgia  and  Mississippi  and  in  some  other  sctions  of  the 
United  States,  the  seed  are  sold  by  the  bushel  instead  of  the  ton. 
It  is  estimated  that  a  bushel  of  seed  will  yield  from  l§  to  2  gallons 
of  oil,  the  amount  depending  upon  the  conditions  under  which  the 
seed  were  grown. 
In  the  crude  state,  the  oil  varies  in  color  from  a  deep  yellow  to  a 
ruby  red,  and  sometimes  to  dark  brown,  or  even  black.  The 
method  of  refining  the  oil  consists  in  washing  it  with  a  solution  of 
alkali.  A  solution  of  caustic  soda,  of  about  12  to  15  per  cent, 
strength,  is  usually  employed.  Of  this,  I  pint  is  added  to  10 
pints  of  the  oil.  The  mixture  is  thoroughly  agitated  for  from 
thirty  to  fifty  minutes.  This  treatment  causes  the  precipitation  of 
the  coloring  and  albuminous  matter;  the  precipitate  is  separated  by 
