546    MATERIA  MEDICA  OF  THE  INTERNATIONAL  EXHIBITION. 
and  carminative,  and  are  also  used  externally  in  the  form  of 
tincture,  for  pains,  etc.  The  tree  which  in  Trinidad  attains  an 
altitude  of  sixty  to  one  hundred  feet  (and  hence  bears  a  very 
improper  specific  name,)  yields  from  incisions  in  its  stem  a 
small  amount  of  balsamic  resin  which  hardens  in  the  air  and  is 
then  undistinguishable  from  Balsam  of  Tolu.  None  of  this  resin 
is  collected  in  Trinidad,  where  the  tree  is  not  very  abundant 
and  apparently  not  indigenous.  Young  plants  of  M.  frutescens, 
raised  from  seeds  sent  by  Dr.  Cruger,  may  be  seen  in  the  Royal 
Gardens  of  Kew. 
Pods  of  Myrospermum,  having  the  posterior  or  winged  por- 
tion broken  off,  are  also  sent  to  the  Exhibition  from  Venezuela. 
No  information  accompanies  them,  except  that  they  are  called 
Sereip'iy  and  are  from  the  province  of  Guayana.  Careful  inspec- 
tion shows  that  they  are  the  produce  of  two  species,  the  smaller 
pods  being  apparently  those  of  M.  frutescens  Jacq.,  and  the 
larger  those  of  some  other  species  which  I  cannot  identify. 
Manna. — Very  few  pharmacologists  having  seen  any  other 
form  of  this  drug  than  that  derived  from  the  Manna  ash  (Frax- 
inus  Ornush.y  it  is  peculiarly  interesting  to  find  among  the 
Materia  Medica  of  the  Exhibition  at  least  four  other  kinds  of 
manna,  namely  the  following:— 
1.  Manna  of  the  Oak  Mr.  H.  S.  Maltass,  of  Smyrna,  has 
sent,  together  with  various  other  interesting  drugs,  a  saccha- 
rine substance  called  Diarbekir  Manna,  respecting  which  he  has 
given  me  the  following  information,  upon  the  authority  of  a  rel- 
ative who  resided  for  two  years  in  Diarbekir.  The  manna  is 
found  upon  the  leaves  of  the  dwarf  oaks,  from  which  it  is  col- 
lected by  the  peasants,  who  use  it  instead  of  butter  in  cooking 
their  food,  and  ascribe  to  it  no  purgative  properties,  at  least 
while  it  is  fresh.  The  manna  is  deposited  upon  trees  much  more 
copiously  after  misty  weather  than  at  any  other  period.  The 
sample  of  oak-manna  in  the  Exhibition  constitutes  a  moist  but 
solid  mass  of  agglutinated  tears,  closely  resembling  some  of  the 
common  qualities  of  ash-manna.  Its  taste  is  simply  saccharine, 
and  agreeable. 
2.  Eucalyptus  Manna.  There  are  several  specimens  in  the 
Exhibition  of  this  substance,  which  is  found  in  the  form  of 
small  rounded  opaque-white  masses  upon  the  leaves  and  younger 
