Am.  Joiir.  Pliarm  \ 
May,  1881.  j 
The  Xanthorrhcea  Resins. 
219 
from  the  chips  to  the  extent  of  a  hundred-weight  per  diem  by  one 
laborer. 
The  acaroid  resin  which  was  first  noticed  in  1789  by  Governor 
Phillips  (Voyage  to  Botany  Bay)  is  met  with  in  tears  and  in  large 
masses  usually,  on  account  of  its  brittleneess,  broken  into  irregular 
pieces.  It  is  intermixed  with  portions  of  wood,  stalks,  earth,  etc.,  and 
when  fractured  has  a  speckled  or  granitic  character.  The  pure  resin 
is  reddish  yellow ;  the  commercial  article  is  externally  brownish  yel- 
low, and  internally  opaque  and  of  a  pure  yellow  color,  resembling 
that  of  gamboge,  but  always  much  lighter.  This  color  description  by 
Guibourt  agrees  with  the  sample  presented  here;  but  since  the  resin 
is  described  by  some  authors  as  being  of  a  deeper  yellow  than  gam- 
boge, it  is  evident  that  it  must  be  sometimes  collected  from  different 
species.  Triturated  with  water,  it  does  not  form  an  emulsion.  When 
fresh  it  has  an  odor  analogous  to  that  of  poplar  buds,  but  much  more 
agreeable  (Guibourt);  to  us  the  odor  appears  to  approach  very  nearly 
that  of  benzoin  mixed  with  a  little  storax.  By  age  the  odor  becomes 
weaker  and  gradually  disappears,  but  it  is  always  developed  on  pow- 
dering or  by  fusion.  The  resin  dissolves  in  alcohol,  leaving  only  0'07 
of  a  gum  insoluble  in  water  and  analogous  to  bassorin.  When  heated 
it  gives  off  white  vapors,  condensing  into  brilliant  small  laminae, 
which  Laugier  regarded  as  benzoic  acid,  but  which  Stenhouse  (1848) 
found  to  consist  largely  of  cinnamic  acid. 
The  brown  resin  has  a  more  balsamic  odor  than  the  preceding ;  the 
tears  are  roundish,  externally  deep  red-brown  and  resembling  dragon's 
blood ;  but  the  fracture  is  shining,  glass-like,  and  in  thin  splinters  it 
is  perfectly  transparent  and  of  a  hyacinth-red  color.  It  is  completely 
soluble  in  alcohol  and  contains  more  volatile  oil,  rendering  it  viscous 
and  somewhat  adhesive. 
The  red  resin  is  in  distinct  tears  of  a  deep  broAvn-red  and  sometimes 
externally  bright  red ;  its  fracture  is  glass-like ;  thin  splinters  are 
transparent  and  ruby-red ;  it  is  completely  soluble  in  alcohol,  the 
ligneous  intermixtures  excepted,  and  its  balsamic  odor  becomes  always 
apparent  on  heating. 
Regarding  the  composition  of  the  Xanthorrhoea  resins,  Pereira 
quotes  the  analyses  of  Lichtenstein  (1799),  Schrader,  Laugier,  Wid- 
man  (1825),  Trommsdorff' (1826)  and  Stenhouse  (1848).  Heated  with 
manganic  binoxide  and  sulphuric  acid  acaroid  resin  evolves  the  odor 
of  oil  of  bitter  almonds,  and  by  the  action  of  nitric  acid  it  yields  a 
