144 
ON  THE  OIL  OF  THE  PURGING  NUT. 
phurous  acid,  and  furnishes  a  black  elastic  substance,  known  in 
the  manufactories  as  sulpho glyceric  acid.  This  substance,  washed 
with  water,  and  then  distilled  with  a  current  of  vapor,  furnishes 
fatty  acids,  which  form  a  crystallized  mass. 
When  the  oil  is  left  in  contact  with  ammoniacal  alcohol  for  a 
month  or  two,  crystals  make  their  appearance  on  the  sides  of  the 
vessel ;  these  disappear,  and  their  place  is  taken  by  a  flocculent 
substance  held  in  suspension  in  the  alcoholic  fluid.  The  oily 
stratum  gradually  diminishes,  and  at  last  disappears.  The  alco- 
hol, when  slowly  evaporated,  deposits  a  white  matter,  of  which 
the  point  of  fusion  and  the  composition  are  not  always  the  same. 
This  result  is  arrived  at  more  quickly  in  operating  by  heat  in  a 
closed  vessel. 
The  substance  purified  by  crystallization  from  alcohol  is  very 
white  and  pearly,  and  fuses  at  152°  «6  F.  into  a  colorless  trans- 
parent fluid.  This  substance  is  not  acted  upon  by  solution  of 
potash  ;  it  is  only  decomposed  by  very  concentrated  potash,  when 
ammonia  is  evolved,  and  a  soap  is  formed  which  is  but  slightly 
soluble  in  water.    From  this  muriatic  acid  separates  a  solid  white 
acid.  Its  analysis  led  to  the  formula  ^J31  which  repre- 
sents the  amide  derived  from  isocetic  acid,  which  I  call  isoceta- 
mide,  C30  H29  0\  NH2. 
Besides  isocetic  acid,  the  oil  contains  another  liquid  acid, 
which  does  not  solidify  at  13°  F.  It  may  be  obtained  by  treating 
with  ether  the  papers  which  have  been  used  in  pressing  the  mix- 
ture of  acids,  or  by  saponifying  the  oil  with  oxide  of  lead  and 
treating  the  soap  with  ether,  which  only  dissolves  the  lead  salt 
of  the  liquid  acid.    This  acid  gave  the  composition  of  oleic  acid. 
The  lead  salt  obtained  directly  by  saponification  with  precipi- 
tated oxide  of  lead,  has  the  composition  2  (C36  H33  O5)  PbO,  HO. 
That  obtained  by  precipitation  is  represented  by  C36  H33  O5, 
PbO. 
It  appears  from  what  precedes,  that  the  oil  of  the  purging  nut 
may  be  usefully  employed  in  the  arts,  either  in  perfumery  or  in 
the  manufacture  of  soap  ;  and  I  have  no  doubt,  that  if,  as  is 
stated,  the  plant  is  very  abundant  in  the  West  Indies,  the  pro- 
duction of  the  oil  will  become  highly  advantageous  to  those  colo- 
nies -London  Ohem.  Qaz^  from  Comptes  Bendus. 
