872  Growing  Medicinal  Plants  in  America.  {Am-J°ur-  Pharm. 
/  a  Dec,  1918. 
alkaloidal  content  is  at  the  maximum,  together  with  proper  control 
of  the  drying  operations,  constitute  a  large  part  of  the  secret  of 
success.  All  this  necessarily  hangs  upon  the  results  of  laboratory 
investigation,  which  must  go  on  hand  in  hand  with  the  agricultural 
operations.  The  author  and  his  associates  have  produced  bella- 
donna in  bulk  running  almost  one  per  cent,  alkaloid-atropin. 
Other  important  medicinal  crops,  such  as  digitalis  and  cannabis, 
present  a  special  problem,  inasmuch  as  the  active  constituents  are 
Fig.  8.    Preparing  to  fill  the  dryer  where  the  herbs  and  roots  are  cured. 
not  determinable  by  chemical  assay,  but  depend  upon  certain  specific 
physiological  tests  which  require  the  services  of  another  group  of 
trained  specialists. 
In  marketing  crude  drugs  the  pharmacopceial  requirements  must 
be  met,  no  matter  how  irrational  these  may  be.  The  requirement  on 
cannabis  calls  for  the  dried  flowering  tops  of  unfertilized  pistillate 
of  female  plants  only.  This  specification  requires  that  before  the 
male  plants  pollinate  experts  must  go  over  the  entire  crop,  plant  by 
plant,  and  distinguish  and  destroy  every  male  individual.  Imme- 
diately the  visible  crop  shrinks  approximately  fifty  per  cent.,  and 
