272    INFLUENCE  OF  CULTIVATION  UPON  MEDICINAL  PLANTS. 
world  upon  a  state  of  things  which  tends  to  lead  the  physician 
astray,  as  well  as  to  compromise  the  health  of  his  patients." 
In  presenting  the  above  abstract  to  our  readers  we  must  beg 
them  to  notice  that  we  do  not  endorse  all  the  statements  there- 
in made;  those  more  particularly  which  have  reference  to  the 
cultivators  of  medicinal  plants  in  France,  are  most  certainly  not 
applicable  to  the  very  intelligent  body  of  men  who  devote  their 
time,  abilities.,  and  money  to  the  cultivation  of  such  plants  in 
this  country.  Nevertheless,  the  paper  is  eminently  suggestive, 
and  the  statements  of  its  author  should  be  carefully  considered 
by  all  who  take  an  interest  in  the  growth  of  medicinal  plants. 
The  opinion  entertained  upon  the  comparative  medicinal  activity 
of  wild  and  cultivated  plants  by  the  framers  of  the  London  Phar- 
macopoeia is,  "  that  the  herb  which  grows  spontaneously  in 
hedges  and  in  uncultivated  places,  is  to  be  preferred  to  that 
cultivated  in  gardens."  At  present,  however,  it  must  be  ad- 
mitted that  no  satisfactory  evidence  can  be  adduced  of  the  greater 
activity  of  wild  plants ;  indeed,  Dr.  Christison  states,  that 
"from  experiments  made  some  years  ago  at  the  Royal  Infirmary 
in  Edinburgh,  with  henbane,  the  inferiority  of  cultivated  plants, 
if  it  exists  at  all,  seems  not  appreciable  in  practice."  According 
to  Merat,  however,  the  superior  activity  of  wild  henbane  has 
been  demonstrated  in  Germany.  Further  experiments  upon  the 
comparative  activity  of  wild  and  cultivated  herbs  are  therefore 
required  before  we  can  arrive  at  any  positive  conclusions  upon 
the  subject.  With  regard  to  valerian,  however,  we  entertain  no 
doubt  as  to  the  greater  activity  of  the  wild  herb. 
The  following  extract  from  Bentley's  Manual  of  Botany,  page 
785,  has  also  direct  bearings  upon  the  matter  in  question.  Thus, 
after  alluding  to  the  effects  of  the  varying  intensity  of  heat, 
light,  etc.,  upon  the  formation  of  the  secretions  of  plants,  Pro- 
fessor Bentley  says  : — "At  present,  much  remains  to  be  dis- 
covered before  we  can  be  said  to  have  anything  like  a  satisfactory 
explanation  of  the  causes  which  influence  the  formation  of  the 
secretions  of  plants ;  for  it  is  found  that  the  same  plants  when 
grown  in  different  parts  of  Great  Britain,  where  the  climatal  dif- 
ferences are  not  strikingly  at  variance,  or  even  at  the  distance 
of  a  few  miles,  or  in  some  cases  a  few  yards,  frequently  vary 
much  as  regards  the  nature  and  activity  of  their  peculiar  secre- 
tions.   A  striking  illustration  of  this  fact  is  mentioned  by  Dr. 
