GUM  COPAL  IN  ANGOLA.  439 
with  small  quantities  of  carbolic  acid,  were  perfectly  preserved 
from  change  even  in  hot  weather. 
These  are  important  experiments.  They  point  out  in  a 
striking  manner  the  difference  between  mere  deodorizers  and 
antiseptics.  Hitherto  attention  has  been  almost  entirely  con- 
fined to  the  deodorization  of  gases  arising  from  putresence. 
The  effect  has  been  combatted,  whilst  the  removal  of  the  cause 
has  received  scarcely  any  attention.  Chloride  of  lime,  one  of 
the  strongest  of  the  class  of  deodorizers,  acts,  as  has  been  shown, 
only  on  the  gases  of  existing  putrefaction,  but  it  has  no  influence 
over  the  future.  Carbolic  acid,  on  the  other  hand,  has  scarcely 
any  action  on  foetid  gases  ;  but  it  attacks  the  cause  which  pro- 
duces them,  and,  at  the  same  time,  puts  the  organic  matter  in 
such  a  state  that  it  never  re-acquires  its  tendency  to  purify.  — 
Lond.  Chem.  News,  June  1,  1866. 
{To  be  Continued.) 
OBSERVATIONS  ON  THE  ORIGIN  AND  GEOGRAPHICAL 
DISTRIBUTION  OF  GUM  COPAL  IN  ANGOLA. 
By  Dr.  Welwitsch. 
This  was  a  resume  of  the  author's  notes  and  observations  on 
the  subject  of  copal,  made  during  his  travels  in  tropical  West 
Africa,  and  if,  he  observed,  "  they  do  not  lead  to  a  conclusive 
result,  especially  in  the  indication  of  the  species  of  trees  which 
at  present  furnish,  or  may  have  formerly  furnished,  this  resin,  T 
hope  at  least  to  show  that  nearly  all  opinions  published  on  this 
subject  by  foregoing  authors  are  more  or  less  erroneous."  The 
gum  copal,  which  is  called  by  the  Bunda  negroes  Ocote,  Cocoto, 
or  Mucocoto,  is  mostly  found  in  sandy  soil,  in  the  hilly  or  moun- 
tainous districts  all  along  the  coast  of  Angola.  The  limits 
within  which,  in  Western  Tropical  Africa  especially,  gum  copal 
is  at  present  or  will  hereafter  be  found,  was  stated  to  be  coinci- 
dent with  the  distribution  of  Adansonia  digitata.  In  the 
province  of  Angola,  the  lands  belonging  to  the  government 
of  Benguella,  extending  south  of  the  Cuanza  River,  yield  the 
most.  The  quantity  exported  from  Benguella  during  the 
period  of  from  1850  to  1860  amounted  to  50,000  arrobas, 
