Am.  Jour.  Pharm. 
June,  1887. 
Oils  of  Erigeron  and  Fireweed, 
303 
had  the  pleasure  of  sending  them  a  full  collection  of  our  essential  oil 
plants  in  the  living  state,  with  which  to  embellish  their  work ;  and 
through  their  courtesy  the  plate  of  fireweed  prepared  for  that  purpose, 
is  here  shown. 
As  no  tests  existed  for  the  identification  of  the  oils,  and  possessing, 
fortunately,  samples  distilled  by  myself  directly  from  the  plants,  so 
that  I  was  able  to  be  positive  as  to  their  purity,  which  is  a  condition  of 
vital  importance ;  the  investigations  recorded  were  made. 
The  credit  of  the  first  researches  is  due  to  Prof.  J.  M.  Maisch,  which 
happened  through  a  curious  circumstance — that  the  fields  of  pepper- 
mint had  been  reported  to  be  contaminated  with  a  weed  called 
"  fireweed."  This  error  was  the  fault  of  the  farmers,  who,  from  a 
lack  of  botanical  knowledge,  gave  the  wrong  name  for  the  plant. 
Prof.  Maisch  rightly  believing  that  the  contaminating  weed  was  the 
erigeron  canadense,  corresponded  with  various  peppermint  growers, 
sending  them  botanical  specimens,  that  there  should  be  no  mistake; 
which  correspondence  and  specimens  I  had  the  pleasure  of  seeing. 
The  correction  of  the  error  was  then  for  the  first  time  made  public  by 
Prof.  Maisch  in  an  article  in  the  American  Journal  of  Phar- 
macy for  1870,  page  120,  as  well  as  in  the  report  on  the  progress  of 
pharmacy  in  the  proceedings  of  the  Am.  Pharm.  Assoc.  for  that  year. 
The  principal  object  sought  in  the  present  article  is  to  establish  tests 
for  the  identification  of  the  oils  rather  than  to  treat  of  the  botany  of 
the  plants  ;  but  a  crude  description  regarding  their  general  character- 
istics may  be  of  interest.*1 
The  true  fireweed — Erechihitis  hieracifolia — is  seldom  found  in  open 
fields  or  by  the  roadside,  growing  exclusively  in,  or  adjacent  to,  clear- 
ings where  timber  has  recently  been  burned.  The  plant  strangely 
seems  to  spring  spontaneously  from  the  ashes  of  old  log  piles  soon  after 
their  formation,  and  continues  to  sprout  up  for  several  seasons  there- 
1  A  more  scientific  description  of  the  plants  in  question  may  be  found  in 
Gray's  Hand  Book  of  Botany,  as  follows : 
Erechthites  hieracifolia,  Raf.  (Fireweed.)  Often  hairy;  stem  grooved  (1°  to 
5°  high)  ;  leaves  lanceolate  or  oblong,  acute,  cut-toothed,  sessile  ;  the  upper 
with  an  auricted  clasping  base.  (Senecio  hieracifolius,  L.) — Moist  woods. 
Common,  especially  northward,  and  in  recent  clearings,  where  the  ground  has 
been  burned  over  ;  whence  the  popular  name.  July-Sept. 
!f  Erigeron  canadense,  L.  (Horse-weed.  Butter-weed.)  Bristly-hairy ;  stem 
erect,  wand-like  (3°-5°  high);  leaves  linear,  mostly  entire ;  thosefroni  the  root 
cut-lobed;  heads  very  numerous  and  small,  cylindrical,  panicled.  Waste 
places ;  a  common  weed,  now  widely  diffused  over  the  world.  July-Oct. 
Ligules  much  shorter  than  their  tube,  white.    (Nat.  in  Eur.  etc). 
