-554  Parification  of  Fats  and  Suets. 
The.  manner  in  which  the  purification  is  effected  is  by  heating  the 
fat  in  a  frying-pan  or  other  suitable  utensil  to  a  temperature  of  about 
140°  to  150°  C,  then  cautiously  sprinkling  upon  it  small  quantities 
of  water.  The  vapor  so  caused  traverses  the  fat,  decomposes  the 
neutral  fatty  substances, — which,  as  shown  by  M.  Chevreul  in  the 
case  of  hircine,  yield  fatty  acids,— the  whole  of  the  fatty  acids  are 
volatilized,  and  the  purification  is  accomplished.  These  conditions,  he 
says,  unite  all  the  elements  which  are  favorable  to  the  elimination  of 
the  volatile  fatty  acids,  which  are  generally  the  material  cause  of  the 
odors  of  fat  substances.  The  product  thus  obtained  is  as  perfectly 
purified  as  the  finest  lard. 
M.  Dubrunfaut  had  so  much  faith  in  the  efficacy  of  this  method  of 
purification,  that  he  called  attention  to  the  large  quantity  of  candle 
tallow  still  in  the  city,  and  stated  that  by  a  modification  of  the  pro- 
cess to  suit  the  known  constituents  of  the  tallow,  the  whole  of  it 
might  be  so  purified  as  to  fit  it  for  use  in  cooking  various  kinds  of 
coarse  flours,  such  as  buckwheat  flour,  and  thus  secured  for  the  pur- 
poses of  alimentation.  The  same  method  might  also,  he  stated,  be 
applied  to  the  large  stock  of  colza  oil. 
In  a  second  note  presented  to  the  Academy,*  M.  Dubrunfaut  again 
called  attention  to  the  facility  with  which  the  large  stocks  of  tallow 
and  colza  oil  might  be  utilized  for  food,  while  the  mineral  oils  would 
suffice  for  the  purposes  of  lighting.  On  this  occasion  he  pointed  ?)ut 
the  similarity  of  the  origin  of  the  kitchen  fats  and  the  tallow  of  com- 
merce, and  said  that  the  absence  from  the  kitchen  fats  of  the  repul- 
sive odor  of  the  tallow  was  due  to  the  method  of  preparation.  In 
the  operation  of  roasting  meat  especially  the  conditions  necessary  for 
the  purification  of  the  fat — the  high  temperature  and  the  superheated 
vapor — were  realized  in  perfection.  And  although  they  were  present 
in  a  less  degree  in  the  operation  of  boiling,  still  there  was  a  real  puri- 
fication. This  opinion  is  supported  by  the  fact  that  tainted  fat,  under- 
going ebullition  in  a  melting-pot  in  the  presence  of  salt  water,  is  puri- 
fied in  proportion  as  the  boiling  is  prolonged. 
As  the  result  of  various  experiments  in  which  colza  oil  was  treated 
according  to  M.  Dubrunfaut's  method,  he  reported  that  the  oil  lost  its 
characteristic  taste  and  odor,  preserving  only  a  slight  savor  that  was 
not  repulsive,  and  would  not  prevent  its  use  in  culinary  operations. 
MM.  Wurtz  and  Willm  reportedf  that  they  had  found  that  when 
/  Am.  JoTO.  PHA.RM. 
X    Dec  1, 1871. 
*  Comptes  Rendus,  Ixxii,  57. 
t  Ibid.,  Ixii,  57. 
