48 
CARYOPHYLLIC  ACID. 
numbers  obtained  by  Calvi  in  his  analyses  differ  very  little  from 
those  required  by  this  formula.  The  acid  employed  for  analysis 
was  purified  by  dissolving  the  crude  acid  in  caustic  potash,  and 
boiling  the  solution  until  the  complete  removal  of  the  hydrocar- 
bon which  accompanies  caryophyllic  acid  in  oil  of  cloves.  The 
analyses  gave — 
Found. 
.  A  ,  Calculated 
i.       ii.         in.        iv.      v.  C20H12O4. 
C      72-7    724        72-7      72-7    72-6  73-1 
H       7-0     7-0         7-0        7.3     7-3  7-4 
The  equivalent  weight  of  caryophyllic  acid  cannot  be  deduced 
from  the  density  of  its  vapor,  because  this  acid  is  altered  at  a 
high  temperature.  Calvi,  in  several  experiments,  obtained  the 
same  result  as  Dumas,  who  gives  the  density  of  the  vapor  of  this 
acid  =  6-4.  The  density  of  vapor  calculated  from  the  formula 
would  be  5-66. 
The  analysis  of  the  baryta-salt  gave  an  amount  of  baryta 
which  would  correspond  with  the  formula  C20H12O4 ;  but  the 
analyses  of  other  salts  gave  variable  and  contradictory  results, 
as  there  is  great  difficulty  in  preparing  these  salts  in  a  truly 
neutral  state.  Thus  the  potash-salt  always  loses  a  certain  quan- 
tity of  acid  during  evaporation. 
The  other  experiments  made  by  Calvi  confirm  the  results  al- 
ready obtained  by  other  chemists.  The  only  interesting  fact 
which  he  ascertained  in  the  investigation  of  the  decomposition 
of  caryophyllic  acid  is  its  conversion  into  a  neutral  oil  by  dis- 
tillation over  anhydrous  baryta.  The  product  thus  obtained  is 
no  longer  attacked  by  solution  of  potash,  and  has  quite  different 
properties  from  caryophyllic  acid,  although  (if  we  may  conclude 
from  the  results  of  one  analysis)  it  has  the  same  composition 
and  the  same  density  of  vapor. — Ohem.  Graz.,  Nov.  l,from  Lie- 
hig's  Annalcn. 
