72 
THE  GUMS  AND  RESINS  OF  COMMERCE. 
America.  But  on  reflection  I  found  that  this  would  entail  much 
repetition,  and  I  am,  therefore,  necessitated  to  fall  back  on  the 
conventional  classification  usually  adopted  of  true  gums,  resins, 
gum  resins,  oleo  resins,  and  elastic  gums,  and  I  hope  to  be  able 
to  furnish  something  new  to  our  current  stock  of  information 
under  each  of  these  heads. 
The  importance  of  this  class  of  commercial  products  will  be 
better  estimated  by  the  statistics  I  shall  be  able  to  furnish  of  the 
trade,  brought  down  to  within  the  last  year  or  two. 
That  there  has  long  been  a  want  of  some  more  detailed  infor- 
mation on  the  gums  and  resins  of  commerce  will  not  be  denied, 
for,  although  much  has  of  late  years  been  done  by  the  several 
local  and  metropolitan  exhibitions  to  collect  and  diffuse  correct 
information,  we  are  still  lamentably  deficient  in  details  as  to  the 
plants  tbat  produce  very  many ;  and  the  learned  Professor  who 
presides  on  this  occasion,  knowing  himself  how  difficult  it  is  to 
identify  plants  without  the  presence  of  the  leaves,  barks,  and 
necessary  adjuncts,  will  readily  be  able  to  excuse  any  accidental 
errors  I  have  fallen  into,  which  his  more  experienced  judgment 
may  be  able  to  correct.  Much  information  respecting  the  gum- 
bearing  trees  of  commerce  and  their  products  is  doubtless  to  be 
found  scattered  through  many  home  and  foreign  scientific 
periodicals,  but  this  bears  rather  on  their  medicinal  value  than 
on  their  commercial  properties  and  uses  in  the  arts  and  manu- 
factures, and  grave  errors  continue  to  be  propagated  in  standard 
works  from  day  to  day  ;  even  in  a  publication  of  weight  and 
influence  like  the  "  Hncyclopcedia  Britannica"  most  of  the  de- 
tails in  the  articles  as  given  in  the  new  edition  (as  far  as  it  has 
proceeded,)  are  nearly  reprinted  verbatim  as  issued  in  its  pages 
some  thirty  or  forty  years  ago. 
There  is  another  work  of  assumed  authority,  where  one  would 
naturally  look  for  some  recent  information  as  to  the  progress  of 
discovery  in  new  gums  and  their  applications,  viz.,  Dr.  Tires 
Dictionary  of  Arts  and  Manufactures ;  but  in  the  last  edition  of 
1853,  the  article  "  Gums"  stands  verbatim  as  it  did  in  the  edi- 
tion fifteen  years  previous,  brief  and  meagre  in  its  character, 
while  that  on  Resins  has  merely  an  addenda  of  a  page  to  the 
previous  stereotyped  matter. 
