1 56 
Oil  of  Bitter  Almonds. 
Am.  Jonr.  Pharni. 
April,  1908. 
meister  and  Hoffmann,  but  more  recently  Schimmel  &  Co.  {Schimmel  s 
Report,  April,  1906,  72)  state  that  it  should  be  1-45  to  170  at  150  ; 
equivalent  to  1-38  to  1-63  at  25 0  C.  Oil  which  is  lower  in  specific 
gravity  than  this  lower  limit  is  suspicious  and  may  probably  con- 
tain added  alcohol,  which  is  sometimes  used  as  a  preservative,  part- 
icularly in  view  of  the  fact  that  the  chemists  of  Schimmel  &  Co. 
have  shown  {Schi?jtmels  Report,  April,  1895,  1 1)  that  a  small  quantity 
of  alcohol  materially  decreases  the  oxidation  to  benzoic  acid.  Spe- 
cific gravity  higher  than  these  limits  indicates  the  presence  of  ex- 
cessive quantities  of  hydrocyanic  acid,  not  however  as  such,  but  in 
the  form  of  benzo-nitrile  produced  by  the  interaction  of  benzaldehyde 
and  hydrocyanic  acid.  For  example,  sample  number  9,  with  a  spe- 
cific gravity  of  1075,  w^  De  seen  by  tne  table  to  have  a  very  large 
quantity  of  hydrocyanic  acid  present  (644  per  cent.);  the  high 
gravity  of  numbers  12,  19  and  20  is  probably  due  to  the  presence 
of  considerable  benzoic  acid. 
Alcohol  Solubility. — Of  the  solubility  requirements  of  the  U.S.P., 
the  one  having  most  importance  is  that  in  70  per  cent,  alcohol.  This 
was  applied  by  carefully  measuring  out  exactly  5  c.c.  of  the  oil  in  a 
graduated  cylinder  and  adding  the  70  per  cent,  alcohol  from  a  burette 
with  constant  shaking  until  a  perfectly  clear  solution  resulted.  By 
this  means  a  very  accurate  determination  of  the  solubility  of  the  oil 
may  be  effected.  None  of  the  samples  failed  to  meet  this  test,  while 
some  of  them,  it  will  be  noted,  required  slightly  less  of  the  alcohol 
to  produce  a  clear  solution.  The  test  is  of  value  and,  to  get  the 
most  out  of  it,  should  be  applied  in  some  such  manner  as  the  above. 
Schimmel  &  Co.  {Schimmel 's  Report,  April,  1906,  72)  consider  that 
a  pure  oil  requires  one  to  two  parts  of  70  per  cent,  alcohol  for  solu- 
tion. 
Chlorinated  Compounds.- — The  presence  or  absence  of  chlorinated 
compounds  has  been  shown  to  be  a  very  excellent  criterion  of  the 
genuineness  of  the  oil  from  the  fact  that  natural  oil  does  not  contain 
any  compounds  which,  by  the  application  of  either  of  these  tests, 
show  the  presence  of  chlorine,  and  that  benzaldehyde  synthetically 
produced  from  toluene  invariably  contains  some  traces  of  chlorinated 
compounds.  These  chlorinated  compounds  may  be  either  those 
produced  by  the  introduction  of  chlorine  direct  into  the  benzene 
nucleus  or  compounds  having  the  chlorine  in  the  side-chain.  This 
statement  is  made  in  the  present  tense,  though  it  should  in  reality 
