220 
Digitalis  Purpurea. 
Am.  Jour.  Pharm. 
April,  19 19. 
they  have  reached  the  height  of  2  inches,  thinning  them  out  to  from 
3  to  5  plants  per  pot  and  then  letting  them  grow  several  weeks 
longer  before  planting  in  the  field. 
6.  From  the  practical  standpoint,  seeding  digitalis  directly  in  the 
•field  proved  unsuccessful. 
7.  Inorganic  fertilizers  applied  to  a  clay  loam  soil  were  effective 
in  increasing  the  yield  of  digitalis.  A  complete  fertilizer  of  1,000 
lbs.  CaC03,  800  lbs.  Ca(H2P04)22H20,  400  lbs.  K2S04,  600  lbs. 
NaNOg  and  100  lbs.  MgS04  per  acre  of  2,000,000  lbs.,  gave  the 
best  results.  With  this  soil,  sodium  nitrate  seemed  to  be  the  most 
essential  single  fertilizer. 
8.  In  sand,  calcium  phosphate  (monobasic)  was  the  most  im- 
portant single  fertilizer  necessary  for  digitalis. 
9.  Neither  manganese  sulphate  nor  ferrous  sulphate,  applied  in 
amounts  of  75  or  150  lbs.  per  acre  of  2,000,000  lbs.  of  a  clay  loam 
soil,  encouraged  a  larger  growth  of  digitalis.  One  hundred  and 
fifty  pounds  per  acre  of  manganese  sulphate  applied  to  a  clay  loam 
soil,  increased  the  activity  of  digitalis  17  per  cent,  over  the  activity 
produced  in  plants  grown  in  soil  receiving  no  manganese  sulphate. 
10.  Chewing  or  sucking  insects  do  not  seem  to  attack  digitalis 
plants.  A  fungus  disease,  which  has  all  the  characteristics  of  a 
root  rot,  attacks  digitalis  plants,  but  has  not  been  found  to  be  very 
destructive. 
11.  Drying  digitalis  leaves  at  ioo°  C,  or  heating  for  one  hour 
at  ioo°  C.  and  then  drying  at  55-600  C,  were  the  most  satisfactory 
methods  from  the  standpoint  of  both  the  amount  of  activity,  as  well 
as  from  the  speed  with  which  the  drying  is  accomplished. 
•  Bibliography. 
1.  Alpers,  W.  C. 
In  Pharm.  Ztg.,  V,  67,  pp.  703-705. 
2.  Alpers,  W.  C. 
191 5.    Remarks  on  Digitalis.    In  Amer.  Jour.  Phar.,  V,  87,  pp.  210-220. 
3.  Barensten,  A. 
191 1.  Digitalis-Digitoxin  Content  in  Different  Organs  of  Cultivated  Plant. 
In  Proc.  Amer.  Phar.  Ass.,  V,  59,  pp.  177-178. 
4.  Boname,  P. 
1909.    Le  manganese  dans  les  sols  et  dans  les  plantes.    In  Bui.  de  la  Sta- 
tion Agronomique  Mauritus,  Bui.  20,  pp.  30-34. 
5.  Borneman,  J.  A. 
1912.  Cultivation  of  medicinal  plants.    In  Amer.  Jour.  Phar.,  V,  84,  pp. 
546-553- 
