BOTANY  BAY  OR  GRASS-TREE  GUM. 
467 
whole  diameter,  around  which  there  is  a  layer  of  resin,  varying 
from  half  an  inch  to  one  inch  or  more  in  thickness,  which  forms 
the  connection  between  the  leaves  and  the  core.  Between  these 
leaves  and  also  adhering  to,  and  covering  them,  is  a  considerable 
quantity  of  resin  ;  resin  ajso  exudes  in  large  lumps  from  the  sides 
of  the  plant. 
The  method  of  obtaining  the  material  in  the  colony  for  this 
purpose  was  as  follows  : — -In  the  first  instance,  the  leaves  and 
resin  were  separated  from  the  core  by  breaking  up  this  plant 
with  an  axe  and  sifting  the  resin  from  the  leaves ;  but  it  was 
found  by  experience  that  as  much  gas  was  obtained  from  an 
equal  weight  of  the  leaves  and  resin  together,  as  from  the  resin 
alone.  The  quantity  of  resin  obtained  from  an  average-sized 
"black  boy  "  was  about  45  lb.  weight.  This  was  collected  easily 
at  the  rate  of  5  lbs.  per  hour,  by  a  person  having  for  his  tools  an 
axe  and  a  sieve. 
Should  the  resin  be  collected  for  export,  I  am  satisfied  that  by 
a  proper  arrangement  of  crushers  and  sieves,  a  laborer,  at  4$. 
per  diem,  (the  colonial  rate),  could  collect  at  least  one  hundred 
weight  per  diem,  enabling  the  resin  to  be  brought  to  market  at 
Ereemantle  for  <£4  per  ton,  the  ton  weight  measuring  forty-five 
cubic  feet  when  pressed.  The  quantity  of  pure  gas  obtained 
by  Captain  Wray's  experiments  was  at  least  four  cubic  feet 
to  the  pound  of  resin  and  leaves,  but  much  more  might  be 
obtained  by  a  more  complete  apparatus. 
A  cart-load  of  the  plants,  eight  in  number,  weighed  1,048 
pounds.  When  the  core  was  removed,  the  leaves  and  resin 
weighed  628  pounds.  This  core  is  very  good  fuel  when  mixed 
with  other  wood.  The  specific  gravity  of  the  gas  is  *888.  The 
products  of  the  distillation  are  gas,  tar  and  coke.  The  tar  ob- 
tained was  about  one  quart  for  every  10  lb.5  and  this,  when  re- 
distilled, gave  8  per  cent,  fluid  oz.  of  naphtha,  and  20  per  cent, 
of  a  sweet,  spirituous,  non-inflammable  liquor.  The  coke  re- 
maining was  about  one-quarter  of  the  original  weight,  and  with 
other  fuel  burns  well.  The  coke  of  the  leaf  has  a  bright  shining 
appearance,  and  when  ground  with  oil,  is  a  very  good  substitute 
for  lamp-black  in  paint.  The  gas  has  a  smell  somewhat  similar 
to  coal  gas,  not  nearly  so  offensive,  but  sufficiently  strong  to 
