Am.  Jour.  Pharm. ) 
Aug.,  1876.  j 
The  International  Exposition. 
37 1 
timber,  in  the  form  of  logs  and  slabs,  partly  polished  so  as  to  show  their  grain  to 
better  advantage,  and  among  them  are  not  less  than  thirty  distinct  species  of 
myrtles,  belonging  to  Myrtus,  Melaleuca,  Eugenia,  Eucalyptus  and  other  genera. 
Similar  exhibits  are  made  by  Tasmania,  Victoria  and  other  Australian  colonies, 
and  altogether  we  have  noticed  timber  from  over  thirty  different  species  of 
Eucalyptus,  the  wood  of  which  varies  between  a  light  yellow  or  brown,  some 
varieties  having  a  distinct  green  tint,  to  a  dark  brown,  red-brown  or  brownish  red, 
the  alburnum  being  in  all  cases  of  a  lighter  color,  and  the  duramen,  or  heart  wood, 
frequently  veined  or  of  a  marbled  appearance.  The  vernacular  names  of  blood- 
wood  (Euc.  corymbosa,  Sm.),  mahogany  [Euc.  marginata  and  resinifera,  Smith), 
yellow  box  (Euc.  hemiphloia^  Muell.,  and  melliodora,  Cunn.),  and  others  have  refer- 
ence to  the  color  of  the  wood  ;  the  name  mahogany  is,  however,  given  in  Australia 
to  several  other  myrtles,  and  probably  to  trees  of  other  natural  orders  having  red- 
colored  wood.  The  green  timber  of  the  Eucalypts  is  stated  to  be  generally  soft, 
and  to  acquire  its  hardness  on  drying,  many  varieties  becoming  then  difficult  to 
work. 
It  is,  however,  not  the  value  of  these  woods  for  the  builder  or  cabinet  maker 
that  gives  to  them  their  medicinal  and  pharmaceutical  importance,  but  rather  the 
so-called  gums  and  the  volatile  oils  which  the  various  species  yield,  some  in  very 
large  quantities.  The  so-called  Botany  bay  kino  is  the  product  obtained  by 
inspissating  the  red  exudation  of  Euc.  resinifera^  Sm.  ;  but  similar  products  are 
obtained  from  other  species,  like  Euc.  corymbosa,  Sm.,  E.  maculata,  Hook.,  E- 
rostrata,  Schlech.,  E.  hemiphloia,  Muel.,  E.  siderophloiz.,  Benth.  and  others,  and  are 
exhibited  in  the  colonial  departments  of  Australia.  The  "gum  "  of  the  last  named 
species  is  shown  in  irregular  lumps,  and  likewise  in  thin  transparent  garnet-red 
scales,  resembling  the  scale  preparations  of  iron.  The  majority  of  these  products 
appear  to  be  closely  allied  to  the  pterocarpus  kino ;  according  to  Wiesner 
("  Zeitschr.  Oest.  Apoth.  Ver.,"  1871),  who  examined  the  exudation  from  16  eu- 
calypts obtained  from  Dr.  Moore,  director  of  the  Botanical  Garden  at  Sidney,  they 
contain  kinotannic,  and  small  quantities  of  catechuic  and  pyrocatechuic  acids,  but 
are  free  from  pectin  compounds.  Some  of  these  varieties  were  entirely  free  from 
gum,  while  others  were  found  to  contain  small,  and  a  few  large  quantities  of  gum  ; 
the  latter  is  particularly  the  case  with  the  "gum  "  from  Euc.gigantea,  Hook.,  which 
is  almost  completely  insoluble  in  alcohol. 
The  separation  of  a  saccharine  substance  upon  the  leaves  and  tender  twigs  of 
some  eucalypts  has  been  noticed  some  years  ago  ("  Am.  Jour.  Pharm  ,"  1862,  p. 
546).  This  Australian  manna  appears  to  be  of  two  kinds,  that  which  is  exuded  by 
Euc.  njiminal'tSy  Labill.,  as  is  supposed  in  consequence  of  the  punctures  of  insects, 
and  the  kind  called  lerp,  which  is  regarded  as  the  secretion  of  an  insect  of  the 
Psylla  family  upon  the  leaves  of  the  mallee  scrub,  the  Euc.  dumosa,  Cunn.  Both 
kinds  appear  not  to  contain  any  mannit. 
The  importance  of  the  eucalypts  as  sources  for  an  almost  unlimited  supply  of 
volatile  oils  of  various  kinds,  has  been  noticed  on  former  occasions  ("  Am.  Jour. 
Pharm.,"  1863,  p.  451),  and,  we  believe,  first  attracted  attention  through  the  obser- 
vations of  Baron  F.  von  Mueller,  director  of  the  Botanical  Garden  at  Melbourne, 
