WOORARA,  OR  SOUTH  AMERICAN  ARROW  POISON.  455 
These  are  finely  scraped,  put  into  a  pot,  covered  with  water, 
then  placed  over  a  slow  fire.  When  it  has  simmered  for  a  quar- 
ter of  an  hour,  the  juice  is  to  be  expressed  by  the  hands,  taking 
care  that  the  skin  be  unbroken.  The  bark  being  now  useless,  is 
thrown  away,  while  the  juice  is  evaporated,  by  means  of  a  mode- 
rate fire,  until  it  has  acquired  the  consistence  of  tar.  These 
Indians  now  take  flat  pieces  of  wood,  called  Cokarito,  and  dip 
them  into  the  mass,  which  adheres  strongly  when  cold.  In 
order  to  preserve  them,  they  are  placed  in  hollow  canes,  closed 
at  both  ends  by  skins.  When  wanted  for  use  the  poison  is  dis- 
solved in  water  and  the  points  of  the  arrows  moistened  with  the 
solution. 
Dr.  Green  first  used  a  specimen  obtained  from  M.  Flourens 
by  Prince  C.  L.  Bonaparte,  at  his  request.  The  second  lot,  and 
which  was  chiefly  used,  came  about  1835  from  Mr.  Smith,  U.  S. 
Consul  at  Para,  to  Dr.  Green.  It  was  in  a  small  half-pint  gourd, 
which  was  about  half  full  of  a  solid,  black  or  brownish  substance, 
having  a  resinous  aspect,  and  soluble  in  water  and  alcohol  to  a 
certain  extent,  facilitated  by  heat.  It  was  kept  in  New  York 
without  special  care,  as  a  curiosity,  until  in  1853  Dr.  Green, 
then  in  Paris,  obtained  a  quantity  for  experiments.  M.  Vul,pian, 
of  Paris,  also  used  some  of  this  specimen  and  found  it  very 
active. 
The  opinion  which  had  obtained,  that  woorara  was  not  a  poison 
when  introduced  into  the  stomach,  has  been,  in  part,  disproved 
by  Dr.  Green  and  others,  although  its  action  is  less  rapid  in  that 
way  than  by  direct  introduction  into  the  circulation. 
The  experiments  of  Drs.  Brainard  and  Green  were  made  with 
guinea  pigs  and  pigeons.  They  found  a  centigramme  (l-7th  of 
a  grain)  would  kill  a  pigeon,  and  two  and  a  half  centigrammes  a 
guinea  pig,  in  three  minutes. 
The  preparation  of  iodine  used  as  a  counterpoison  was  iodine 
one  part,  iodide  of  potassium  two  parts,  water  48  parts.  This, 
mixture,  after  being  heated  to  the  temperature  of  the  body,  was 
injected  under  the  skin  of  the  animals  mentioned  without  any 
ill  effects.  When  a  poisonous  quantity  of  the  solution  of  woo- 
rara was  mixed  with  five  times  its  bulk  of  this  iodine  liquid,  the 
whole  was  injected  under  the  skin  of  a  guinea  pig  without  its 
causing  any  ill  effects. 
