164  ON  THE  SO-CALLED  OIL  OF  CINNAMON  LEAF. 
properties  of  benzoic  acid.  Their  quantity  was,  however,  so  very 
small,  that  they  could  not  be  subjected  to  analysis.  I  at  first 
suspected  these  crystals  to  be  cinnamic  acid,  but  I  soon  found 
this  was  not  the  case,  for  on  treating  them  with  a  hot  solution  of 
hypochlorite  of  lime,  they  did  not  give  the  very  characteristic 
reaction  of  cinnamic  acid,  namely,  the  production  of  that  singu- 
lar chlorinated  oil  which  is  always  produced  when  cinnamic  acid 
is  treated  in  this  way.  That  these  crystals  were  really  benzoic 
acid,  was  ascertained  as  follows  : — When  the  last  portions  of  the 
oil  which  had  come  over,  together  with  the  residue  remaining  in 
the  retort  were  digested  with  strong  nitric  acid,  along  with  much 
oxalic  acid,  a  small  quantity  of  another  kind  of  crystals  were 
obtained,  which  in  appearance  and  properties  agreed  perfectly 
with  nitro-benzoic  acid.  They  were  carefully  purified  and  sub- 
jected to  analysis. 
0.1125  grammes  gave  0.2095  grammes  of  carbonic  acid,  and 
0.0305  grammes  of  water. 
The  calculation  for  nitro-benzoic  acid  (C14  H5  (N04)  Q4)  re- 
quires— 
Theory.  Pound. 
014  =  84   50.29    50-79 
H.  =  5  3.00  -  -  -  -  3.91 
N  =  14  -  -  -  -    8-38  -  -  -  -  — 
Oa  =  64    38.33    — 
167  100.00 
Of  the  silver  salt  of  this  acid,  0.12  grammes  gave  0.046  gram- 
mes of  silver,  corresponding  to  38.33  per  cent. ;  theory  requires 
38.32. 
The  first  portions  of  the  colorless  oil  which  distilled  over  were 
again  rectified,  when  the  boiling  point  was  by  no  means  constant, 
though  the  greater  portion  of  the  oil  came  over  at  a  temperature 
approaching  the  boiling  point  of  eugenic  acid. 
The  oil  was  treated  with  an  excess  of  potash,  and  the  hydro- 
carbon which  did  not  combine  with  the  alkali,  was  drawn  off  by 
a  pippette.  It  was  next  treated  with  fused  potash,  then  with 
chloride  of  calcium,  and  lastly  rectified  over  potassium.  In  this 
way  a  colorless,  highly  refractive  liquid  was  obtained,  the  greater 
portion  of  which  distilled  over  between  160°  and  165°  C.  Its 
