286  Selected  Pharmaceutical  Formulas.  { Am^)°"1r-  ?£fm' 
variations  within  limits  of  the  strength  of  acid  and  alkali  used  do 
not  materially  affect  the  results  obtained;  but  with  oil  cakes,  espe- 
cially those  made  from  seeds,  with  a  more  or  less  hard  "  husk," 
very  wide  differences  in  results  may  arise,  according  as  to  whether 
1.25  or  2  per  cent,  acid  and  alkali  have  been  employed.  In  the  case, 
for  example,  of  palm  nut  and  similar  cakes  it  is  impossible  to  prop- 
erly effect  the  hydrolysis  with  the  weaker  solutions,  and  even  with 
the  2  per  cent,  solutions  vigorous  boiling  for  half  an  hour  is  essen- 
tial. It  is  best  to  operate  on  the  material  after  extraction  of  the  oil 
with  ether.  Three  grammes  of  the  ground  sample  are  extracted  with 
ether  and  then  boiled  vigorously  for  half  an  hour  with  125  Cc.  of  2 
per  cent,  sulphuric  acid,  the  volume  of  the  liquid  being  kept  con- 
stant during  the  operation.  The  liquid  is  diluted  to  400  or  500  Cc. 
with  water,  and  allowed  to  settle.  The  liquid  is  then  poured  through 
a  filter — preferably  a  piece  of  fine  linen — the  residue  is  washed 
on  to  this,  and  then  transferred  to  the  original  boiling  vessel,  and 
boiled  for  half  an  hour  with  125  Cc.  of  2  per  cent,  caustic  alkali 
solution.  The  liquid  is  diluted  as  before,  allowed  to  settle,  and  the 
insoluble  fiber  collected,  either  on  a  counterpoised  filter  or  on  the 
linen  filter,  from  which  it  can  readily  be  completely  removed.  The 
fiber  is  washed  to  free  it  from  alkali,  then  treated  with  a  little  dilute 
acid,  followed  by  water,  and  finally  with  alcohol.  The  fiber  is  dried 
at  ioo°  C.  to  constant  weight,  and  burnt,  any  mineral  matter  found 
being  deducted  from  the  weight  of  the  fiber. 
SELECTED  PHARMACEUTICAL  FORMULAS  FROM  THE 
CHEMIST'S  CALENDAR. 
(Continued  from  Page  20/.) 
FoOT-LlQUID. 
Liquid  formaldehydi    3ixss 
Sp.  rosmarini    3SS 
A  teaspoonful  to  a  basin  of  water. 
Very  good  for  hardening  the  feet  and  healing  blisters.  Much 
appreciated  in  Army  circles. 
Acid  Aperient  Mixture. 
Magnesii  sulphat   3nj 
Acid,  sulph.  dil   3iij 
Syrup,  aurantii    3iss 
Aq.  menth.  pip.  ad   Oj 
