ON  THE  OIL  OF  THE  PURGING  NUT. 
143 
Several  substances  give  rise  to  an  acid  presenting  a  similar 
composition,  but  varying  either  in  their  point  of  fusion  or  in 
their  appearance.  Thus,  Walter  extracted  from  oil  of  ben  an 
acid  which  crystallized  in  granules,  and  fused  at  125°-127°  F, 
(benic  acid.)  Hardwick  obtained  from  the  oil  of  Bassia  longifolia 
an  acid  of  a  waxy  aspect,  which  was  deposited  from  its  ethereal 
solution  in  granular  tubercles,  and  fused  between  131°-9  and 
133°. 7  F.  He  represented  it  as  C30  H30  O4,  and  named  it  bassic 
acid.  In  the  Chinese  wax,  Borck  found  an  acid  which  fused  at 
141°'8-143°-6  F.,  and  separated  from  alcohol  in  nacreous  la- 
mellae ;  to  this  he  gives  the  name  of  stillistearic  acid,  and  ascribes 
to  it  the  above  composition.  Lastly,  Heintz,  in  examining  sper- 
maceti, obtained  an  acid  of  the  same  composition  (cetie  acid,) 
which  crystallized  in  nacreous  spangles,  fusible  at  128°-3  F.  The 
acid  examined  by  me  having  the  closest  analogy  to  cetic  acid,  I 
shall  call  it  isocetic  acid. 
Isocetic  JEther,  obtained  by  the  ordinary  processes,  is  inodor- 
ous ;  it  fuses  by  the  heat  of  the  hand,  and  solidifies  at  69°-8,  re- 
maining  perfectly  transparent,  but  acquiring  a  crystalline  tex- 
ture. The  numbers  obtained  by  analysis  agree  with  the  for- 
mula— 
Q30  H29  Q3  Q4  JJ5  Q> 
The  action  of  sulphurous  acid  upon  the  oil  furnished  a  result 
which  deserves  mention,  and  which  will  assist  in  the  explanation 
of  the  mode  of  action  of  this  acid  upon  certain  neutral  fatty 
matters.  A  current  of  sulphurous  acid  was  passed  into  the  oil, 
and  the  whole  left  standing  ;  at  the  end  of  three  months  a  depo- 
sit crystallized  in  granules  was  found  in  the  oil ;  this  was  sepa- 
rated, pressed  and  purified  by  alcohol.  It  is  fusible  at  136°4  F., 
combines  with  bases  to  form  salts,  and  is  very  soluble  in  alcohol ; 
its  composition  is  that  of  the  solid  acid  of  the  oil,  but  its  point  of 
fusion  is  higher.  The  sulphurous  acid  must  then  become  partially 
converted  into  sulphuric  acid,  and  the  latter  will  have  produced 
a  partial  saponification.  Acid  saponification  may  therefore  take 
place  slowly  in  the  cold,  without  coloration,  under  the  influence 
of  a  small  quantity  of  acid ;  and  I  need  not  insist  upon  the  im- 
portance of  this  fact. 
When  the  oil  is  treated  with  ordinary  sulphuric  acid,  keeping 
the  temperature  at  230°  F.t  the  mass  becomes  blacky  evolves  sul- 
