BOTANY  BAY  OR  GRASS-TREE  GUM. 
465 
BOTANY  BAY,  OR  GRASS-TREE  GUM. 
By  P.  L.  Simmonds,  F.S.S. 
This  remarkable  resin,  which  is  known  in  different  parts  of 
Australia  under  various  local  names,  as  "  black  boy  "  gum,  grass- 
tree  gum,  etc.,  would  seem  to  be  obtained  from  several  species  of 
Xanthorrlicea,  of  which  there  are  six  or  seven  well-defined 
species  in  Australia.  The  resin  has  long  been  known  among 
druggists  as  gum  acroides.  It  was  generically  named  by  Swartz 
from  its  peculiar  color. 
This  resin  was  first  described  in  Governor  Phillip's  voyage  to 
New  South  Wales  in  1788.  Mr.  Phillips  states  that  it  was  em- 
ployed by  the  natives  and  first  settlers  as  a  medicine  in  cases  of 
diarrhoea.  The  resin  of  X.  hastilis  as  it  occurs  in  commerce 
sometimes  forms  masses  of  considerable  size ;  but  as  it  is  very 
brittle,  although  tolerably  hard,  it  usually  arrives  in  small 
pieces,  and  in  the  state  of  a  coarse  powder.  Its  color  is  a  deep 
yellow,  with  a  slightly  reddish  shade,  and  considerably  resem- 
bling gamboge,  but  darker  and  less  pleasing.  The  color  of  its 
powder  is  greenish-yellow.  When  chewed  it  does  not  dissolve 
or  stick  to  the  teeth,  but  tastes  slightly  astringent  and  aromatic, 
like  storax  or  benzoin.  When  gently  heated  it  melts,  and  when 
strongly  heated  it  burns  with  a  smoky  flame,  and  emits  a  fragrant 
odor  resembling  balsam  of  tolu,  containing  apparently  cinnamic 
acid  mixed  with  a  very  little  benzoic.  The  quantity  of  carbazotic 
acid  which  this  resin  yields  when  treated  with  nitric  acid  is  very 
great,  and  it  is  easily  purified.  Incidental  mention  has  already 
been  made  of  this  resin,  ("Technologist,"  vol.  ii.  p.  25;  iii.  p. 
19 ;  and  v.  p.  227),  but  as  it  appears  to  be  occupying  increased 
attention  in  Australia  just  now,  some  further  details  respecting 
it  may  prove  useful. 
The  grass-tree  is  one  great  characteristic  of  the  scenery  and 
of  the  vegetation  of  Australia.  It  puts  one  in  mind  of  a  tall 
black  native  with  a  spear  in  his  hand  ornamented  with  a  tuft  of 
rushes.  On  the  spear  is  found  an  excellent,  clear,  transparent- 
gum,  and  from  the  lowest  part  of  the  tree  oozes  a  black  gum, 
which  makes  a  powerful  cement,  used  by  the  natives  for  fastening 
stone  heads  on  their  hammers.    The  resin  may  be  obtained  in 
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