490  Work  in  an  English  Herb  Garden.  j^fXrfiSi? 
that  the  leaves  from  cultivated  plants  are  inferior  to  those  obtained 
from  the  wild  plant;  we  have  not  been  able  to  find,  however,  that 
these  requirements  have  any  rational  foundation,  for  first  and 
second  year's  leaves,  grown  side  by  side,  have  proved  identical  in 
their  activity  and  the  cultivated  leaves  are  at  least  as  active  as  those 
grown  wild.  As  no  practical  method  of  chemically  testing  digitalis  is 
known,  the  minimal  lethal  dose  (  for  frogs  )  has  been  determined  and 
the  plant  cultivated  on  the  Wellcome  Materia  Medica  Farm  has 
Fig.  2. 
Gathering  Belladonna.    Wellcome  Materia  Medica  Farm. 
yielded  a  B.P.  tincture  having  an  M.L.D.  of  0.4  c.c.  per  100-grams 
on  a  three-hour  test,  thus  showing  that  it  is  possessed  of  a  very  high 
degree  of  activity. 
Hyoscyamus  niger  is  also  a  biennial  plant  of  which  it  is  an 
official  requirement  that  the  second  year's  growth  should  alone  be 
employed,  yet  as  regards  the  activity  we  find  the  percentages  of 
alkaloid  contained  in  plants  of  first  and  second  year's  growth  are 
identical,  thus,  there  was  found : 
