AmNovSarm  }    ?ure  and  Adulterated  Oil  of  Cassia.  577 
ipso  facto  from  the  analyses.  We  collect  them,  briefly,  in  the  follow- 
ing synopsis : — 
1.  Cassia  Oil  should  have,  at  15°  C.  a  specific  gravity  of  1,050  to 
1,070. 
2.  On  distilling,  about  90  per  cent,  pure  cassia  oil  should  pass  over. 
The  residue  must  not  become  solid  after  cooling  and  take  the  charac- 
ter of  a  brittle  rosin,  but  must  remain,  at  least,  semi-fluid.  It  may 
amount  to  from  6  to  7  per  cent.,  but  in  no  case  to  more  than  10  per 
cent. 
No  practical  value  for  the  detection  of  resin  can  be  attached  to  test- 
ing the  solubility  of  the  oil  in  more  or  less  diluted  spirit,  as  is  proven 
by  the  examination  of  oils  which  had  been  purposely  mixed  with  resin 
and  petroleum. 
As  a  matter  of  course  it  is  possible  that  adulteration  with  fatty  oil 
will  again,  occasionally,  be  resorted  to,  and  that  the  fluid  residue 
obtained  by  distilling,  will  amount  to  more  than  10  per  cent.  Any 
such  oil  must  of  course  be  rejected  by  the  Hongkong  and  Macao 
firms.  We  shall,  henceforth,  exercise  a  strict  control  over  the  oils 
coming  into  the  market  and  keep  an  eye  on  the  different  brands,  in 
order  to  be  able,  when  occasion  may  offer,  to  proceed  also  against 
other  means  of  adulteration,  whilst  on  the  other  hand  we  shall  take 
pleasure  in  publishing  from  time  to  time  those  brands  which  excel  in 
quality. 
For  examining  cassia  oil  weigh  out  about  50  gm.  of  it  into  a  small 
fraction-retort,  connect  it  with  the  cooling-tube  and  place  the  ther- 
mometer, by  means  of  a  perforated  cork- stopper,  about  5  to  10  centi- 
meters above  the  fluid.  The  retort  may  not  be  more  than  half  full. 
At  first  some  water  escapes,  with  a  cracking  noise,  from  the  fluid.  The 
oil  commences,  usually,  to  boil  at  about  200°.  The  thermometer 
rises  quickly  to  240°.  The  principal  quantity  of  the  oil  distils  over 
between  240°  and  260°.  At  last,  white  vapors  develop  in  the  retort, 
the  thermometer  rising,  at  the  same  time,  to  280°  or  290°.  When 
this  has  taken  place,  the  distillation  is  to  be  interrupted  ;  the  residue 
is  allowed  to  cool  in  the  retort  and  weighed  with  it.  If  the  residue 
becomes  hard  and  solid  after  cooling,  the  oil  is  to  be  considered  adul- 
terated and  rejected.  Genuine,  non-adulterated  oil  also  leaves  a  resi- 
due (up  to  about  10  per  cent.).  But  it  never  becomes  solid  and 
remains  in  a  semi-fluid  state,  also  after  having  cooled  off  completely. 
The  fraction-retort  used  must  be  properly  cleaned  with  hot  spirit. 
