218 
Digitalis  Purpurea. 
Am.  Jo^r.  Pharm. 
April,  1919. 
Insects  and  Diseases  Affecting  Digitalis. 
Digitalis  plants,  quite  different  from  hyoscyamus  and  belladonna, 
Koch  (8),  (9),  are  not  attacked  by  the  various  chewing  and  suck- 
ing insects.  Hence,  they  require  no  spraying  nor  such  particular 
attention  as  hyoscyamus  and  belladonna.  It  was  noted  that  grass- 
hoppers will  chew  the  leaves,  but  as  yet,  the  destruction  by  grass- 
hoppers has  been  negligible. 
A  fungus  disease,  having  all  the  characteristics  of  root  rot,  was 
found  present  on  several  digitalis  plants  in  the  field.  This  did  not 
prove  very  destructive,  as  only  a  few  plants  were  attacked  and  in 
these  cases,  the  plants  withstood  the  attack  of  this  fungus. 
Effect  of  Drying  at  Different  Temperatures  upon  the 
Activity  of  Digitalis. 
Opinions  with  regard  to  the  methods  of  drying  digitalis  leaves, 
seem  to  differ  considerably.  Alpers  (1)  says  the  leaves  should  be 
dried  at  once  as  completely  as  possible,  in  a  well  ventilated  drying 
closet  at  a  temperature  not  exceeding  ioo°  C.  Perrot  and  Goris 
(3)  propose  the  method  of  sterilizing  the  leaves,  thus  destroying  the 
enzymes,  when  first  drying  digitalis  leaves. 
Borneman  (5)  concludes  that  the  digitalis  plants  should  be  dried 
quickly  by  artificial  heat,  the  temperature  being  brought  up  to  ioo° 
C.  as  soon  as  possible  and  maintained  at  this  point. 
Newcomb  (12)  summarizes  in  drying  digitalis,  applying  artificial 
heat  in  a  closet  at  a  temperature  of  75  to  ioo°  C.  for  8-10  hours  a 
day,  required  3  days  to  reduce  the  moisture  to  4  per  cent.  By  this 
method,  the  green  color  was  never  lost.  He  says  that  these  methods 
were  particularly  suitable  in  that  the  leaves  were  quickly  dried,  it 
fixed  the  desirable  green  color,  and  at  the  same  time,  the  active 
principles  were  not  in  any  way  injured. 
An  experiment  on  determining  the  effect  of  drying  under  various 
conditions  on  the  activity  of  digitalis  leaves,  was  made.  A  large 
sample  of  about  6  kilos  of  digitalis  leaves  was  cut  into  small  portions. 
After  thoroughly  mixing  this  material,  it  was  divided  into  five 
samples  of  equal  size.  Each  of  these  samples  were  dried  at  a  dif- 
ferent temperature,  as  shown  in  the  table  below.  After  drying  these 
samples,  they  were  submitted  for  analysis. 
