^cembef^sos?'}      Conservation  and  Cultivation  of  Plants.  567 
even  the  same  plant  varies  greatly.  My  first  experience  in  the 
growing  of  belladonna  and  inula  was  rather  interesting  in  that  I 
sowed  the  seeds  in  open  ground  one  year  and  saw  no  evidence  of 
the  plants  until  the  next  year.  I  have  reason  to  believe  that  con- 
ditions of  this  kind  exist  in  nature  not  infrequently.  Our  trouble 
in  growing  certain  plants  like  lobelia  is  probably  due  to  our  lack  of 
knowledge  concerning  the  entire  life-history  of  the  plant,  as  it  is  no 
doubt  true  that  certain  plants  require  a  longer  period  of  rest  before 
resuming  their  vegetative  activities  than  others.  Mr.  O.  D.  Graff, 
of  Berry,  111.,  first  called  my  attention  to  the  fact  that  lobelia  ap- 
peared to  be  abundant  in  that  locality  only  every  other  year,  and 
stated  that  1897  was  an  off-year  for  this  plant.  My  own  rather 
meagre  observations  would  tend  to  confirm  this  view  not  only  with 
regard  to  this  but  other  plants.  A  prominent  rose-grower  has  in- 
formed me  that  rose  seeds  of  the  same  plant  may  require  anywhere 
from  three  weeks  to  three  years  for  germination. 
THE  COLLECTION,  CURING  AND  YIELD  OF  DRUGS. 
In  a  previous  paper  (this  Journal,  1902,  page  311)  I  have  called 
attention  to  the  rules  to  be  observed  in  the  time  of  collection  of 
vegetable  drugs  and  to  the  importance  of  properly  drying  them  and 
preparing  them  for  the  market.  When  not  only  the  nature  of  the 
plant,  but  the  diversity  of  constituents  of  vegetable  drugs  is  taken  into 
consideration,  it  will  be  admitted  that  the  collection  and  preparation 
of  them  for  the  market  is  really  a  fine  art,  requiring  a  keen  appre- 
ciation and  extended  knowledge  of  the  subject,  and  is  one  which 
cannot  be  put  by  lightly  as  of  little  consequence.  The  large  crude 
drug  collectors  give  instruction  to  their  employees  as  to  the  methods 
to  be  followed  in  the  preparation  of  the  drug  ;  this  knowledge  hav- 
ing been  acquired  as  the  result  of  years  of  experience.  We  are 
apt  to  think  that  the  only  drugs  that  require  particular  care  are 
those  like  tobacco,  vanilla  and  gentian,  where  in  addition  to  drying 
there  is  a  curing  process  that  takes  place  ;  but  this  is  true  also  of 
digitalis,  the  solanaceous  leaves  and  many  of  the  important  drugs. 
While  the  quality  thus  acquired,  like  that  of  teas  and  wines,  etc., 
cannot  readily  be  determined  by  any  assay  process,  yet  the  therapeu- 
tist is  able  to  appreciate  the  difference  between  the  drug  carefully 
collected  and  prepared  from  the  one  that  is  carelessly  handled. 
The  cultivation  of  certain  medicinal  plants  has  made  it  possible 
