CARYOPHYLLIC  ACID. 
47 
charcoal  until  it  may  be  entirely  recovered.  In  neutral  or  alka- 
line liquors  the  reaction  is  not  so  well  performed.  In  Barres- 
will's  liquor,  for  instance,  the  copper  deposited  upon  the  char- 
coal has  a  very  beautiful  iridescent  appearance.  When  nitric 
acid,  hydrochloric  acid,  or  sulphuric  acid  is  used  to  acidify  the 
solutions,  the  effect  is  the  same,  only  that  it  is  clearest  with 
sulphuric  acid. 
2nd.  I  have  observed  that  the  metallic  salts  of  organic  acids 
are  less  easily  decomposed  than  those  which  contain  mineral 
acids. 
3rd.  The  solutions  of  silver  in  nitric  acid,  whether  neutral  or 
acid,  and  chloride  of  silver  dissolved  in  ammonia,  are  easily  de- 
composed by  freshly  calcined  wood  charcoal.  The  silver  is  soon 
seen  to  cover  the  charcoal  in  the  most  beautiful  manner ;  it 
sometimes  appears  crystallized. 
4th.  Copper  may,  by  this  same  means,  be  precipitated  from 
ammoniacal  solutions ;  but  if  these  solutions  likewise  contain 
silver,  the  latter  will  be  first  reduced. 
5th.  Finally,  incandescent  wood  charcoal  plunged  in  Fowler's 
solution,  acidified  with  sulphuric  acid,  produces  a  very  agreeable 
ether  which  I  intend  to  examine.  It  will  be  easy  to  make  in 
this  way,  by  varying  the  acids,  nitric,  acetic,  sulphuric  ethers,  &c. 
6th.  Zinc,  iron,  platinum,  lead,  and  mercury  may  be  precipi- 
tated by  wood  charcoal,  but  they  re-dissolve  in  acid  liquors  ;  this 
does  not  occur  at  all  with  silver,  and  with  copper  not  until 
twenty-four  hours  after  the  operation. — Chemist,  from  Gomptes 
Rendus,  Oct.,  1856. 
CARYOPHYLLIC  ACID. 
By  L.  Chiozza. 
Calvi  has  repeatedly  analysed  the  caryophyllic  acid  procured 
from  oil  of  cloves,  in  order  to  test  the  admissibility  of  the  formula 
established  for  it  by  Gerhardt.  The  previous  analyses  made  by 
Dumas,  Ettling,  and  Beckmann  gave  more  carbon  than  is  re- 
quired according  to  the  formula  proposed  by  Grerhart.  The 
