328 
Correspondence. 
Am.  Jour.  Pharm. 
July,  1915. 
mentioned  in  our  original  paper  is  potassium  fluoride,  which  salt 
we  found  to  have  a  remarkable  effect  on  the  formation  and  color 
of  the  Prussian  blue.  Potassium  chloride,  however,  prevents  the 
formation  of  a  pure  blue  color  and  renders  the  test  less  delicate. 
We  would,  therefore,  appreciate  very  much  if  you  would  make  a 
correction  in  an  early  issue. 
A.  VlEHOEVER, 
C.  O.  Johns. 
Drug  Plants  Not  Usually  Profitable. 
Although  a  large  amount  of  money  is  spent  annually  for  the  im- 
portations of  crude  drugs,  and  the  extermination  of  a  number  of 
valuable  native  drug  plants  is  threatened,  government  specialists  do 
not  believe  that  the  growing  of  drug  plants  offers  any  unusual  oppor- 
tunities for  profit  to  the  American  farmer.  Drug  plants  are  subject 
to  the  same  diseases  and  risks  as  other  crops,  and,  in  addition, 
knowledge  of  the  best  methods  of  cultivation  and  handling  is  less 
general  than  in  the  case  of  other  and  better  known  crops.  In 
issuing  a  new  bulletin,  Farmers'  Bulletin  663,  "  Drug  Plants  Under 
Cultivation,"  the  Department  of  Agriculture,  therefore,  warns  farm- 
ers that  in  order  to  have  the  cultivation  of  drug  plants  financially 
successful  in  this  country  the  introduction  of  improved  methods 
and  the  extensive  use  of  machinery  is  probably  necessary.  Under 
these  circumstances  the  natural  tendency  will  be  to  increase  the 
production  in  the  interest  of  economy.  The  demand  for  many  drug 
plants,  however,  is  so  limited  that  if  large  areas  are  brought  under 
cultivation  there  is  considerable  danger  of  overproduction.  Pros- 
pective growers  are  urged,  therefore,  to  acquaint  themselves  with 
market  conditions  before  investing  any  considerable  sum  of  money 
in  this  way. 
On  the  other  hand,  the  number  of  drug  plants  which  may  be 
grown  in  the  United  States  is  large.  Many  native  medicinal  plants 
which  are  found  in  their  wild  state  in  a  few  sections  have  been 
successfully  cultivated  in  situations  far  beyond  their  natural  range. 
In  suitable  soil  and  under  favorable  weather  conditions  the  following 
plants  have  done  well  under  cultivation  in  numerous  places  in  the 
Central  and  Eastern  States,  and,  if  the  difference  in  climatic  con- 
ditions is  not  too  great,  will  probably  be  suitable  in  other  regions : 
Anise,  belladonna,  burdock,  caraway,  catnip,  camomile,  conium, 
