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THE  GUMS  AND  RESINS  OF  COMMERCE.  135 
a  portion  of  volatile  oil,  in  which  case  they  partake  of  the  smell 
and  acid  taste  of  that  oil.  Resins  generally  burn  with  a  strong 
yellow  flame,  emitting  at  the  same  time  a  vast  quantity  of  smoke, 
Dammer  affords  a  good  example  of  the  resins. 
It  is  strange  that  of  the  origin  of  substances  at  once  so  valua- 
ble and  so  familiar  to  us  so  little  should  be  known.  The  sources 
of  the  dammer  and  many  of  the  wood  oils  from  Singapore  and 
the  Eastern  Archipelago  are  little  known,  nor  are  the  copals, 
the  anime,  the  myrrhs,  and  other  valuable  gums  and  resins  from 
Africa,  Zanzibar,  &c,  well  defined. 
Colophony,  the  ordinary  resin  of  commerce,  is  the  residuum 
remaining  in  the  body  of  the  still  after  common  turpentiue  has 
been  submitted  to  distillation  for  the  manufacture  of  the  oil  of 
turpentine  of  commerce,  or  spirit  of  turpentine.  The  black 
resin,  or  colophony,  is  the  cooled  brittle  mass  in  the  state  in 
which  it  leaves  the  still;  the  amber  or  yellow-colored  is  the  same 
resin  mixed  with  about  one-eighth  part  of  water  while  it  is  yet 
fluid. 
Large  quantities  of  resin  oil,  or  pine  oil,  as  it  is  generally 
called,  are  made  in  the  metropolis  and  in  the  neighborhood  of 
Liverpool,  Hull,  Bristol,  and  Glasgow,  and  it  is  employed  in  the 
manufacture  of  grease  for  lubricating  the  bearings  of  heavy 
machinery,  and  the  axles  of  railway  wagons,  &c.  It  is  much 
used  in  France  for  the  manufacture  of  printing  ink,  and  hence 
a  principal  source  of  the  unpleasant  odor  of  some  of  the  French 
newspapers.  About  23,000  tons  of  rosin  are  annually  imported, 
of  which  the  bulk  comes  from  America,  and  a  little  from  the 
Hanse  Towns.  One  of  the  most  important  oleo-resins  in  a  com- 
mercial point  of  view  is  turpentine,  of  which  we  import  from 
17,000  to  25,000  tons  per  annum,  almost  exclusively  from  the 
United  States.  The  comparative  receipts  in  the  last  nine  years 
have  been  as  follows  : — 
Tons. 
Tons. 
1846,  . 
17,897 
1851,  . 
21,790 
1847,  . 
16,193 
1852,  . 
21,080 
1848,  . 
20,089 
1853,  . 
19,650 
1849,  . 
20,666 
1854,  . 
17,038 
1850,  . 
21,731 
In  the  State  of  North  Carolina,  about  800,000  to  1,000,000 
barrels  of  turpentine  are  now  annually  made,  giving  occupation 
