Am.  Jour.  Pharm. 
Nov.,  1893. 
African  Copaiba. 
Comparison  of  Essential*  Oils. 
545 
Properties  and  Tests. 
Percentage  of  oil. 
Specific  gravity. 
Rotatory  power. 
Solubility  at  150  in  abso- 
lute alcohol. 
In  petroleum  ether. 
In  ether  720. 
In  ether  735. 
In  rectified  spirit. 
In  glacial  acetic  acid. 
Range  of  boiling  point. 
Behavior  to  dry  hydro- 
chloric acid  gas  in 
freezing  mixture. 
Digested  for  6  hours 
with  metallic  sodium 
and  fractionated. 
Behavior  to  chloroform- 
ic  gold  chloride  solu- 
tion with  1  per  cent, 
absolute  alcohol. 
Iodine  absorption  in  16 
hours. 
Distilled  with  bichro- 
mate of  potash  and 
sulphuric  acid. 
African. 
j  39  per  cent. 
0-9180. 
+  20°  42'. 
not  soluble  1  in  50, 
251-8. 
Bl  uish-green ,  265-2670 
C. 
Maracaibo. 
42  per  cent. 
0-9052. 
-  34°  18'. 
1  in  1. 
257*9- 
Bluish  oil,  rapidly 
becoming  brown 
(2570  C.  falling). 
Para. 
A,  80-2  pei  cent. 
B,  64-3  per  cent. 
0*9060. 
-  28°  55'. 
1  in  1. 
1  in  1. 
1  in  2%. 
1  in  2.y2. 
not  soluble  1  in  20. 
1  in  1%. 
252-2600  C. 
Becomes  wine-red, 
turbid,  deposits 
after  a  time,  but 
no  crystals. 
2620  C,  falling  to  2300 
C,  j  green  oil. 
Becomes  green  only 
no  deposit  after  1 
hour. 
233. 
Blue  color  fades  on 
standing  1  hour 
exposed  to  air  (2520 
C.  falling). 
1  in  1. 
1  in  3. 
1  in  3. 
not  soluble  1  in  50. 
20u-^/3  . 
Becomes  wine-red, 
turbid,  deposits 
after  a  time,  but 
no  crystals. 
Blue  oil,  permanent. 
Reduces  immediate-  | 
ly,  deposits  metal- 
lic gold. 
1  in  1. 
1  in  3. 
1  in  3. 
1  in  19. 
1  in  5. 
245-2550  c. 
Becomes  wine-red, 
turbid,  deposits 
after  a  time,  but 
no  crystals. 
Blue  fluorescence 
only. 
Becomes  green,  no 
deposit  after  1 
hour. 
The  African  oleoresin  is  slightly  fluorescent,  possesses  an  aromatic 
piperaceous  smell,  and  has  a  specific  gravity  of  0-985  to  i-ooo  at 
1 5°  C.  It  deposits  crystals  on  standing,  and  yields  on  distillation 
with  steam  about  40  per  cent,  of  volatile  oil. 
The  oleoresin  does  not  lose  its  fluidity  when  heated  in  a  sealed 
tube  to  2200  C,  a  property  which  distinguishes  it  from  gurjun 
balsam. 
The  object  of  this  additional  paper  is  to  lay  before  you  the  results 
of  a  more  extended  examination  of  the  volatile  oil  and  crystalline 
and  other  resins  briefly  mentioned  in  that  note,  and  a  comparison  ot 
them  with  those  obtained  from  South  American  copaiba. 
Volatile  Oil. 
The  average  yield  of  volatile  oil  obtained  by  distillation  with 
steam  from  the  samples  of  African  copaiba  examined  was  39  per 
cent.  The  oil  was  of  a  pale  yellow  color,  had  a  specific  gravity  of 
0-9185  at  160  C,  and  a  notation  of  -f  200  42  with  a  tube  20  cm. 
long  at  1 6°  C.  It  is  soluble  in  its  own  weight  of  petroleum  ether,  in 
3  parts  of  ether,  7  of  glacial  acetic  acid,  but  is  not  completely 
soluble  in  50  parts  of  rectified  spirit  or  absolute  alcohol.    One  nun- 
