194 
Laboratory  Notes. 
Am.  Jour.  Pharm. 
April,  1896. 
OIL  OF  CASSIA. 
As  is  well  known,  this  substance  is  produced  in  the  Orient,  and  is 
practically  controlled  by  the  Chinese.  That  it  is  occasionally  found 
adulterated  in  original  containers  is  not  new  to  many,  but  the  crude- 
ness  of  the  adulterations  is  known  to  a  smaller  number.  In  general, 
the  U.  S.  P.  requirements  are  satisfactory  for  detecting  fraudulent 
goods,  but  whenever  it  is  possible  the  percent,  of  cinnamic  alde- 
hyde should  always  be  estimated.  In  order  to  do  this,  it  is  neces- 
sary to  be  in  possession  of  a  glass  flask,  about  100  cubic  centimetres 
capacity,  with  a  neck  about  13  centimetres  long,  8  millimetres  internal 
diameter  and  graduated  in  tenths  up  to  6  cubic  centimetres.  It  is 
impossible  to  obtain  this  flask  from  dealers  in  this  country  at  present, 
but  it  can  readily  be  secured  from  Messrs.  Schimmel  &  Co.,  of  essen- 
tial oil  fame. 
To  estimate  the  aldehyde  in  a  sample  of  oil,  proceed  as  follows  > 
into  the  long- necked  flask  measure  exactly  10  cubic  centimetres  of 
the  oil ;  warm  the  flask  and  contents  well  on  a  water  bath,  add  about 
20  cubic  centimetres  of  a  30  percent,  sodium  bisulphite  solution — a 
curdy  mass  results  almost  immediately — agitate  the  mixture  thor- 
oughly several  times,  carefully  avoiding  loss  by  squirting.  The 
flask  is  then  placed  on  a  hot  water  bath,  and  heated  until  the  coagu- 
lum  has  assumed  a  perfectly  fluid  state.  Add  another  small  portion 
of  the  sodium  bisulphite  solution,  shake,  and  warm  on  the  water  bath 
as  before.  Proceed  in  this  manner  until  the  flask  is  about  three- 
fourths  filled,  the  coagulum  is  completely,  dissolved  and  a  clear 
layer  of  oil  floats  on  the  solution.  Not  a  speck  of  curd  must  be 
visible.  Remove  the  flask  from  the  water  bath,  cool,  and  fill  up  the 
flask  with  the  bisulphite  solution  or  a  saturated  solution  of  salt  until 
the  oil  has  completely  risen  into  the  neck,  and  the  line  of  demarca- 
tion coincides  exactly  with  the  lowest  mark  on  the  neck  of  the 
flask.  The  oily  portion  represents  the  non-aldehydes,  excepting  the 
cinnamic  acid  which  is  dissolved  by  the  aqueous  solution,  contained 
in  the  oil.  On  deducting  the  number  of  cubic  centimetres  of  the 
oily  substance  from  ten,  and  multiplying  the  remainder  by  ten,  we 
obtain  the  percent,  of  aldehyde  in  the  oil. 
With  a  pure  oil  the  estimation  can  be  made  in  one-half  an  hour, 
and  never  more  than  two  hours  should  be  consumed.    With  an 
1  1890,  Semi-annual  Report,  Schimmel  &  Co.,  Oct.,  page  15,  and  1891,  Oct., 
page  15;  1892,  Odorographia,  by  J.  C.  Sawer,  Vol.  I,  page  216. 
