438  Cultivation  of  Aromatic  Plants.     ^  Am.  jour. ^Pharm- 
A  detailed  discussion  of  the  methods  of  producing  these  well- 
known  oils  will  probably  not  be  of  sufficient  interest  to  the  perfume 
trade  to  justify  its  repetition  here,  the  subject  having  been  repeat- 
edly covered  in  trade  journals  and  technical  books.  It  may  be  oppor- 
tune, however,  to  mention  the  case  of  peppermint  oil  as  an  instance 
of  the  American  tendency  to  simplify  foreign  methods  of  produc- 
tion when  once  established  in  an  industry  that  was  formerly  con- 
fined to  European  countries.  In  England  the  peppermint  roots  or 
rhizomes  are  allowed  to  sprout  in  the  spring,  and  when  the  sprouts 
have  developed  into  plants  two  or  three  inches  high  these  plants  are 
separately  set  in  the  ground  at  regular  intervals,  thereafter  being 
cultivated  entirely  by  hand.  In  America  the  roots  are  laid  in  longi- 
tudinal trenches  three  feet  apart  and  the  cultivation  is  done  with 
horses,  both  planting  and  cultivation  being  much  cheaper  this  way. 
The  English  yield  averages  about  fifteen  pounds  to  the  acre,  whereas 
ours  is  usually  not  less  than  twenty-five,  and  often  much  more. 
When  the  crop  is  harvested,  they  distil  theirs  over  boiling  water, 
several  hours  being  necessary  for  the  complete  distillation  of  one 
vat-full.  We  distil  ours  with  live  steam  and  a  much  larger  vat-full 
requires  only  twenty  minutes  time  in  a  modern  still. 
Of  the  oils  which  we  secure  chiefly  from  European  sources  the 
most  important  to  the  perfume  trade  seem  to  be  lavender,  rose,  rose- 
mary, geranium,  neroli,  orris  root,  and  the  flower  odors  isolated  by 
the  enfleurage  or  maceration  processes,  as  jasmine,  tuberose,  violet, 
jonquil,  hyacinth,  etc. 
The  first  of  these,  lavender,  which  is  grown  extensively  in  the 
mint-producing  districts  of  England,  has  been  successfully  grown 
experimentally  in  Michigan  where  the  Mitcham  peppermint  is  so 
extensively  grown.  The  only  serious  difficulty  that  presents  itself 
is  due  to  the  frequent  occurrence  of  heavy  snows  which  tend  to 
break  down  the  bushes.  Lavender  is  grown  preferably  in  nicely 
rounded,  compact  bushes,  and  the  flowers  are  cut  off  by  grasping  a 
handful  of  twigs  at  once  and  cutting  them  off  together,  with  a 
sickle.  Heavy  snows  flatten  the  bushes  out,  making  the  gathering 
of  the  flowers  more  difficult.  However,  this  is  not  a  prohibitive  dif- ' 
ficulty.  There  are  localities  in  the  Carolinas  and  other  parts  of  the 
country  where  lavender  could  be  grown  with  no  climatic  difficulty. 
The  distillation  of  rose  has  never  been  extensively  undertaken 
in  this  country.  In  California,  where  the  rose  grows  so  prolifically, 
the  atmosphere  is  probably  too  dry  for  a  sufficient  oil  yield.    It  is 
