Am.  Tour.  Pharm. 
April,  1919. 
Digitalis  Purpurea. 
215 
tories.  Fertilizers  were  applied  as  shown  in  the  table  below.  Seeds 
were  planted  on  May  28,  and  about  6  months  later,  the  plants  were 
harvested  and  dried  in  the  oven  at  ioo°  C.  for  4  days.  The  moisture 
conditions  were  maintained  at  the  physical  optimum  of  the  soil. 
On  studying  the  results  of  Table  II,  it  will  be  seen  that  adding 
fertilizers  to  this  heavy  clay  loam  soil  increased  the  growth  of  digi- 
talis to  some  extent,  however,  in  most  of  the  cases,  the  increase  was 
comparatively  small.  In  the  determination  where  a  complete  fertil- 
izer was  applied,  the  increase  in  weight  over  the  control  was  greatest. 
In  the  pots  where  no  sodium  nitrate  was  added,  the  weights  of 
digitalis  harvested  was  very  little  more  than  in  the  control  which 
recevied  no  fertilizer. 
To  more  fully  determine  the  absolute  fertilizer  requirements  of 
digitalis  plants,  the  above  recorded  fertilizer  experiment  was  re- 
peated using  sand.  The  results  of  this  experiment  are  presented  in 
Table  III. 
TABLE  III. 
Showing  the  Effect  of  Inorganic  Fertilizers  upon  Digitalis  Plants  in 
Sand. 
/ 
Lab.  No. 
Fertilizer  Application. 
Weight  of  Plants, 
Grs. 
Average, 
Grs. 
421 
No  fertilizer  
i-7 
422 
1-3 
1.4 
423 
1.1 
424 
Complete  fertilizer4  
4-7 
42  5 
2-3 
3-1 
426 
2.4 
427 
Complete  fertilizer— Ca  (H2PO4) 22H2O . 
i-5 
428 
1.9 
1-5 
429 
1.2 
430 
3-9 
431 
3-7 
3-7 
432 
3-5 
433 
Complete  fertilizer — NaNC»3  
2.2 
434 
2-5 
2.3 
435 
2.3 
436 
3-5 
437 
2.3 
3-2 
438 
3-8 
It  is  very  apparent  from  the  results  shown  in  Table  III  that  cer- 
tain inorganic  fertilizers  were  necessary  for  the  maximum  growth 
4  Complete  fertilizer— 1,000  lbs.  CaC03,  800  lbs.  Ca  (H,P04)22H20,  400  lbs. 
K2S04,  600  lbs  XaX03  and  100  lbs.  MgS04  per  acre  of  2,000,000  lbs. 
