514  Extraction  of  Animal  Fats,  etc.      {^''N^Ti.  187^' 
covered  with  drops  of  a  milky  liquid,  which  is  probably  water  and 
finely  divided  sulphur.  With  paraffin  the  tubes  remain  clear  and 
bright,  except  for  a  little  sulphur  sublimate  close  to  the  neck  of  the 
flask. 
I  observe  that  Reinsch  recommends  a  laboratory  process  for  obtain- 
ing pure  sulphhydric  acid  by  heating  in  a  glass  flask  equal  parts  of 
sulphur  and  suet.  The  recommendation  does  not  seem  to  have  been 
generally  followed,  but  the  advantages  resulting  from  the  substitution 
of  paraffin  for  suet  may  lead  to  the  more  usual  adoption  of  this  pro- 
cess. 
Addiewell  Chemical  Works,  Sejjt.  4,  1871. 
— Chemical  News,  Oct.  5th,  1871. 
EXTRACTION  OF  ANIMAL  FATS  TO  BE  USED  EITHER  AS  FOOD 
OR  FOR  COSxMETIC  PURPOSES. 
By  Dr.  H.  Yohl. 
The  fresh  fat  is  first  as  much  as  possible  freed  from  membranes 
and  flesh,  next  cut  up  either  into  small  discs  or  cubes,  and  then  thor- 
oughly washed  with  cold  water  (which  should  contain  the  least  possi- 
ble quantity  of  lime,  therefore  fresh  river,  or,  better,  good  rain-water, 
should  be  used)  until  all  blood  is  entirely  removed.  The  fat  is  next 
put  into  a  cylindrical  stoneware  vessel,  1*25  metres  high  and  0*5 
metre  inside  diameter,  this  vessel  being  placed  in  a  water-bath  and 
provided  with  a  tap  at  the  bottom,  so  placed  that  the  vessel  may  be 
emptied  without  removing  it  from  the  water-bath.  The  vessel  having 
been  filled  for  three-fourths  of  its  capacity  with  fat,  there  is  placed 
on  the  top  of  it  a  stoneware  perforated  disc,  and  next  poured  over  it 
(the  fat)  very  dilute  pure  hydrochloric  acid — 10  per  cent,  of  the 
weight  of  the  fat  of  an  acid  made  up  of  3  lbs.  of  chemically  pure  HCl 
at  1*12  sp.  gr.  to  100  lbs.  of  water  (sulphuric  acid  is  not  to  be  sub- 
stituted, because  its  solvent  power  for  membranes  is  very  slight). 
This  having  been  done,  the  stoneware  vessel  is  closed  with  a  well  fit- 
ting cover,  and  the  water-bath  heated.  From  the  fat,  while  melting, 
the  perforated  cover  carries,  by  slowly  sinking  downwards,  all  the  im- 
purities, as  far  as  they  are  not  dissolved  by  the  acid,  which  at  the 
end  of  the  operation  is  run  ofi"  by  aid  of  the  tap.  The  fat  is  then, 
while  yet  molten,  %  ashed  several  times  with  warm  water,  to  which, 
for  the  last  washing,  some  carbonate  of  magnesia  is  added.  The  acid 
liquid  yields,  along  with  phosphorite  or  other  native  phosphate  of 
