INFLUENCE  OF  CULTIVATION  UPON  MEDICINAL  PLANTS.  273 
Christison,  who  found  that  some  umbelliferous  plants,  as  Cieuta 
virosa  (Water  Hemlock),  and  (Enanthe  crocata  (Hemlock  Water 
Dropwort),  which  are  poisonous  in  most  districts  of  England, 
were  innocuous  when  grown  near  Edinburgh.  The  causes  which 
lead  to  such  differences  are  at  present  obscure,  but  the  varying 
conditions  of  soil  and  moisture  under  which  such  plants  are 
grown,  have  doubtless  an  important  influence  upon  their  secre- 
tions. In  a  pharmaceutical  point  of  view,  so  far  as  the  active 
properties  of  the  various  medicinal  preparations  obtained  from 
plants  are  concerned,  this  modification  in  the  secretions  of  plants 
by  such  causes  is  of  much  interest,  and  would  amply  repay  in- 
vestigation, for  it  cannot  be  doubted  but  that  each  plant  will 
only  form  its  proper  secretions  when  grown  under  those  circum- 
stances which  are  natural  to  it,  and  that  consequently  any  change 
from  these  conditions  will  modify  to  some  extent  the  properties 
of  the  plant.  I  cannot  but  believe  that  here  we  have  an  expla- 
nation, to  some  extent  at  least,  of  the  cause  of  the  varying 
strength  of  medicinal  preparations  obtained  from  plants  grown 
in  different  parts  of  this  country,  or  in  different  soils,  etc." 
If  future  experiments  should  demonstrate  in  a  conclusive 
manner  that  wild  plants  are  more  active  than  those  under  culti- 
vation, it  will  be  necessary  to  ascertain  what  are  the  conditions 
of  heat,  light,  exposure,  soil,  moisture,  etc.,  which  are  most 
favorable  to  the  full  development  of  the  medicinal  properties  of 
each  plant,  in  order  that  the  cultivator  may  place  them,  as  far 
as  he  is  able,  under  such  conditions.  Many  of  our  medicinal 
plants  are  now  employed  so  extensively  that  they  could  not  be 
obtained  in  any  proportion  to  the  demand  for  them  from  wild 
localities,  and  hence  cultivation  must  be  resorted  to  to  keep  up 
the  necessary  supply.  In  conclusion,  we  would  urge  upon  our 
cultivators  of  medicinal  plants  to  study  to  place  the  plants  they 
cultivate,  in  as  nearly  as  can  be  ascertained  at  present,  their 
natural  condition,  and  then  we  have  no  fear  that  their  medicinal 
properties  will  be  sensibly  diminished  ;  indeed,  we  see  little 
reason  to  doubt,  that  as  our  knowledge  of  vegetable  physiology 
and  chemistry  increases,  when  the  conditions  under  which  the 
different  secretions  of  each  particular  plant  have  been  thoroughly 
investigated,  we  may  increase  rather  than  diminish  their  active 
properties   by  proper  cultivation. — London  Pharm.  Journ. 
18 
