''VcT  mT''  }      Purification  of  Fats  and  Suets.  553^ 
Among  the  many  memoirs  presented  to  the  French  Academy  with 
the  last-mentioned  object,  were  some  that  treated  of  a  subject  not 
without  interest  to  pharmacists, — the  purification  of  fats  and  suets, — 
of  which  the  following  is  a  resume. 
M.  A.  Boillot  communicated  a  method  which  he  stated  had  yielded 
excellent  results,  and  for  which  he  claimed  the  merits  of  simplicity 
and  moderate  cost.*  Two  litres  of  lime-water  is  added  to  one  kiloli- 
tre of  the  fat  or  suet,  mixed  well  together,  and  kept  over  the  fire  two 
or  three  hours.  It  is  then  left  to  cool,  and,  when  it  has  become  pasty 
and  acquired  a  sufficient  consistence,  it  is  decanted,  placed  in  flannel 
or  linen,  and  submitted  to  an  increasing  pressure,  when  water  and 
oleic  acid,  containing  besides  some  solid  fatty  acids,  from  which  it  can 
readily  be  freed  afterwards,  passes  through.  The  oily  mass,  after 
two  or  three  days,  acquires  a  whiteness  which  leaves  nothing  to  be 
desired ;  and  when  freed  from  the  little  lime  that  it  contains  by  treat- 
ing it  with  water  slightly  acidulated  with  sulphuric  acid,  may  be  used 
for  purposes  of  illumination.  Fat  thus  prepared  loses  its  bad  odor, 
and  acquires  a  remarkable  hardness  and  whiteness  ;t  and  if  run  into 
water  to  which  a  small  quantity  of  sulphuric  or  acetic  acid,  or  vinegar, 
has  been  added,  it  will  be  thoroughly  purified,  and  may  be  employed 
for  all  purposes  to  which  the  best  fats  are  applied. 
M.  Dubrunfaut  states  J  that  the  most  tainted  fat  may  Be  deprived 
0^  its  characteristic  odor  by  submitting  it  to  the  operation  of  frying ; 
and  that,  after  being  thus  treated  in  a  manner  specified,  it  may  be 
used  for  all  culinary  preparations,  and  even  for  pastry.  For  this  fact 
he  furnishes  the  following  scientific  explanation. 
M.  Dubrunfaut  has  practically  ascertained,  by  laboratory  and  man- 
ufacturing experiments,  that  fish  oil  is  radically  deprived  of  its  odorous 
principle  by  simply  heating  it  to  a  high  temperature  (330  C.)  He 
has  also  found  that  the  fatty  acids  are  volatilized  in  a  current  of 
steam  at  a  temperature  above  100°  C,  whilst  the  neutral  fats  remain 
perfectly  fixed.  Finally,  he  has  found  that  the  neutral  fats  comport 
themselves  in  a  similar  manner  to  the  fatty  acids  under  the  influence 
of  a  current  of  steam,  if  they  have  previously  been  heated  to  a  tem- 
perature of  from  300°  to  330°  C. 
*  Comptes  Rendus,  Ixxii,  36. 
t  The  use  of  lime  for  the  purpose  of  blanching  lard  has  already  been  reported 
from  America.  There,  however,  it  appears  to  be  left  as  an  impurity  in  the  lard. 
See  Pharm.  Journ.,  1st  ser.,  vol.  i,  p.  1043. 
X  Comptes  Rendus,  Ixxii,  37. 
