Am.  Jour.  Pharm.\ 
January,  1901.  J 
Drug  Culture. 
13 
In  my  observations  upon  the  European  narcotic  drugs,  the  most 
thrifty  specimens,  rich  in  alkaloids,  were  found  among  the  dense 
foliage  of  forests  where  the  rays  of  the  sun  never  reach  the  soil, 
and,  as  naturally  would  be  expected,  these  same  plants,  when  culti- 
vated in  narrow  valleys  with  a  northern  or  eastern  aspect,  were  the 
most  prolific  in  growth. 
In  considering  the  influence  of  climate  upon  drug  culture  we 
must  also  bear  in  mind  that  there  are  vertical  as  well  as  horizontal 
zones  of  vegetation,  and  we  must  therefore  expect  that  the  growth 
of  drug  plants  will  follow  the  well-known  range  of  trees,  shrubs, 
vines,  grasses,  etc.,  in  this  respect. 1 
As  to  the  soil  best  adapted  to  the  growth  of  medicinal  plants  we 
know  almost  nothing.  It  will  be  necessary  to  study  each  plant  by 
itself  in  this  respect.  Taking  the  European-grown  drugs  as  types, 
it  has  seemed  to  me  that  those  regions  where  the  soil  was  a  mix- 
ture of  humus  and  calcareous  earths  were  the  most  productive; 
soils  rich  in  sand  or  clay  produced  the  least. 
In  England  aconite  and  henbane  are  cultivated  in  Kent  on  light 
sandy  soils.  They  grow  wild  on  marshy  land.  The  soil  in  Lincoln- 
shire, where  drugs  are  cultivated,  contains  a  good  percentage  of  fine 
sand  and  vegetable  matter  and  is  not  very  high  in  lime. 
In  another  section,  where  the  same  drugs  are  grown,  the  soil  is  a 
brown  loam  lying  over  a  chalk  formation,  and  contains  15  per 
cent,  of  lime.  The  vegetable  matter  from  this  soil  is  not  very 
high.  From  the  Continent  a  sample  of  soil  on  which  lavender  and 
several  narcotic  herbs  are  grown  was  reported  to  contain  35  per 
cent,  vegetable  matter,  51  per  cent,  of  sand  (quite  fine),  10  per  cent, 
of  lime  and  2  per  cent,  of  phosphoric  acid. 
So  far  as  I  could  learn  the  potash  content  in  these  soils  was  not 
high.  Observing  the  conditions  under  which  many  medicinal 
plants  thrive,  we  might  conclude  that  rich  soil  was  not  a  necessity. 
In  one  of  my  experiments  I  selected  a  very  poor  red  shale  soil 
where  grass  would  not  grow,  even  under  fertilization  with  compost, 
and  on  this  soil  the  growth  of  rhubarb,  digitalis,  conium,  cotton, 
aconite,  etc.,  was  a  pronounced  success. 2 
1  The  writer  is  preparing  a  list  of  the  common  drug  plants  suited  to  the  tem- 
perate zone  of  the  United  States  with  such  information  as  can  be  gathered  as  to 
the  zone  of  vertical  cultivation,  and  will  be  pleased  to  receive  aid  and  sug- 
gestions. 
2  An  analysis  of  this  red  shale  soil  gave  the  following  results  : 
