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DETECTION  OF  CROTON  OIL  IN  MIXTURES, 
and  useful  guide  to  all  who  may  visit  its  shores.  The  politics 
of  the  country,  tremendous  tiger-hunts,  and  the  description  of 
miraculous  metallic  arteries,  and  not  veins,  so  often  mentioned 
but  as  yet  unseen,  I  have  left,  as  a  wide  and  open  field  to  be 
again  explored  by  those  successful  authors,  whose  works  have 
shed  so  strange  a  brilliancy  on  this  poor  and  unworthy  country. 
The  medical  Flora  might  be  published  separately  and  in 
numbers,  thus  allowing  me  time,  means  and  opportunity  of 
continuing  the  work  from  the  rich  funds  of  the  altos  of  Guate- 
mala and  of  Costa  Rica.  A  residence  of  ten  years,  my  profes- 
sion, much  intimacy  with  the  clergy  and  principal  people  of  the 
country,  have  afforded  me  many  opportunities  of  information,  un- 
attainable by  other  means.  To  reduce  this  into  useful  form  has 
been  my  object. 
Having  but  few  friends  in  the  United  States  interested  in 
such  pursuits,  I  have  presumed  on  your  time  and  politeness,  by 
these  remarks  on  my  own  affairs. 
With  much  respect,  I  remain,  dear  sir, 
Yours  truly, 
Charles  Dorat. 
To  Dr.  J.  Carson,  Prof.  Mat.  Med.  University  of  Pennsylvania. 
N.  B.  The  Pajuil  and  other  birds  are  found  in  numbers  on 
the  balsam  trees,  feeding  on  the  young  and  tender  seeds.  The 
wild  hogs  are  also  fond  of  them. 
ON  THE  DETECTION  OF  CROTON  OIL  IN  MIXTURES, 
By  John  M.  Maisch. 
It  may  be  sometimes  of  importance  to  prove  in  a  fixed  oil  the 
presence  of  croton  oil.  Its  peculiar  effect  upon  the  skin  will 
show  it  wherever  it  occurs  in  a  considerable  proportion.  There 
is,  generally,  little  danger  of  mistaking  for  it  other  oils  of  similar 
properties ;  as,  for  instance,  the  sulphuretted  oils  of  mustard, 
garlic,  &c,  which  manifest  themselves  by  their  odor.  Fixed 
oils,  however,  might  contain  a  sulphuretted  oil,  with  its  odor 
masked  by  some  other  perfume,  and  in  so  small  a  proportion  as 
to  produce  only  after  several  applications  a  slight  inflammation 
of  the  skin;  croton  oil  might  be  present  under  similar  cir- 
