34 
African  Copaiba  " So-called! 
Am.  Jour.  Pharm 
Jan.,  1892. 
be  indigenous  to  tropical  Africa,1  but  the  information  as  to  the 
production  of  oleo-resins  by  these  species  is  very  meagre,  the  only 
description  of  a  secretion  of  economic  value  being  given  by  Bennett, 
who  describes  Copaifera  Gtubourtiana,  known  by  the  natives  as  the 
"  Kobo  "  tree,  as  yielding  a  copal. 
Of  the  closely  allied  genus  Hardwickia,  the  oleo-resin  of  certain 
species  of  which  resembles  that  of  the  Copaifera,  as  far  as  I  can 
learn  only  one  African  variety  is  known,  viz  :  Hardwickia  Mannii* 
and  it  is  doubted  whether  even  this  is  not  a  species  of  Copaifera. 
With  such  scanty  botanical  information  available,  and  the  exact 
district  of  their  production  at  present  unascertained,  it  appeared 
desirable  to  compare  these  African  oleo-resins  with  the  products  of 
the  South  American  species  of  Copaifera,  with  the  object  of  deter- 
mining their  relationship  or  otherwise  by  physical  and  chemical 
characteristics. 
The  two  oleo-resins  from  West  Africa,  which  I  will  designate  as 
(A)  and  (B),  were  dissimilar  in  appearance,  due  probably  to  a  differ- 
ence in  the  manipulation  of  the  two  samples. 
(A)  was  light  brown  in  color,  slightly  fluorescent,  having  an 
aromatic,  somewhat  piperaceous  odor,  a  specific  gravity  of  0-987  at 
1 50  C,  and  on  standing,  deposited  a  quantity  of  small  crystals.  It 
yielded  by  distillation  with  steam  37-9  per  cent,  of  a  pale  yellow 
essential  oil,  which,  when  dried  over  chloride  of  calcium  distilled  at 
264-2700  C,  and  had  a  specific  gravity  of  0  9173  at  150  C.  The  oil 
was  readily  soluble  in  petroleum  ether  and  ether  (-73 5),  less  soluble  in 
pure  ether  (-720),  and  only  slightly  soluble  in  rectified  spirit  and 
glacial  acetic  acid.  The  crystals  deposited  by  the  oleo-resin  were 
repeatedly  crystallized  from  petroleum  ether,  and  when  pure,  had  a 
melting  point  of  1240  C.  (uncorrected),  had  a  faint  yellow  color  and 
were  distinctly  acid  in  reaction. 
(B)  was  darker  in  color,  more  markedly  fluorescent,  possessed  an 
aromatic,  piperaceous,  but  slightly  empyreumatic  smell,  and  on 
standing,  nearly  half  its  bulk  separated  as  an  ill-defined  crystalline 
mass.  The  specific  gravity  of  the  oleo-resin,  thoroughly  mixed,  was 
1-002  at  1 50  C;  but  after  removal  of  the  deposited  mass,  the  fluid 
1  "  Pharmacographia  "  (1874),  p.  200  ;  Bentham  and  Hooker,  vol.  i,  p.  585  ;  De 
Candolle's  "  Prodromus, "  vol.  ii,  p.  509;  Oliver,  "Flora  of  Tropical  Africa," 
vol.  ii,  p.  3T3- 
2  Oliver,  "  Flora  of  Tropical  Africa,"  vol.  ii,  p.  316. 
