720  Standardisation  of  Digitalis  Preparations.  {ANovemberP1i9ri™' 
iments  and  arrived  at  essentially  the  same  general  conclusions.  The 
experiments  and  conclusions  outlined  in  this  paper  are  herewith 
offered  merely  as  additional  evidence  upon  the  subject  of  the  rela- 
tive sensitiveness  of  these  tests. 
A  STANDARDIZATION  OF  DIGITALIS  PREPARATIONS.1 
By  Edgar  Berry,  M.Sc,  A.I.C. 
In  presenting  the  following  treatise  I  wish  to  thank  H.  E.  Annett, 
Esq.,  M.D.,  D.P.H.  (late  professor  of  comparative  pathology  of 
Liverpool  University),  who  has  very  kindly  performed  the  injec- 
tions for  the  Minimum  Lethal  Dose  experiments,  I  myself  not  being 
licensed  for  this,  and  also  Messrs.  Evans  Sons,  Lescher  and  Webb, 
Ltd.,  for  permission  to  publish  results  obtained  in  their  research 
laboratories  at  Runcorn. 
From  my  last  investigation  of  Digitalis  Purpurea  (P.  J Dec.  26, 
191 5),  based  on  frog  heart  perfusions,  three  conclusions  were  drawn. 
1.  The  water-soluble  glucosides  of  digitalis  apparently  have  the 
most  desirable  tonic  and  slowing  effect  on  the  heart,  and  are  non- 
cumulative  and  non-toxic. 
2.  Digitoxin  is  cumulative  and  toxic,  appearing  to  enter  into 
actual  combination  with  the  heart  muscle. 
3.  The  leaf  saponins  have  a  harmful  and  toxic  effect  on  the  heart. 
The  constituents  of  digitalis  vary  to  a  very  large  extent  under 
different  conditions  of  growth.  This  variation  is  influenced  by 
climate,  soil,  conditions  of  growth  (sunshine  or  shade),  humidity, 
and  period  of  growth.  For  example,  I  found  a  sample  of  Spanish 
leaves  to  be  very  rich  in  saponin,  although,  apart  from  this,  the  per- 
fusion experiments  showed  a  good  physiological  action.  Again,  a 
tincture  made  from  the  first  large  leaves  of  seedlings  of  four  months' 
growth  from  the  first  appearance  of  leaves,  packed  closely  together 
in  cold  frames  (thus  excluding  sunlight),  I  found  to  have  the  action 
of  pure  water  soluble  glucosides,  digitoxin  apparently  not  yet  hav- 
ing been  formed. 
From  these  considerations — in  view  of  the  number  of  existing 
official  preparations  containing  the  whole  of  the  soluble  constituents 
1  Reprinted  from  The  Pharmaceutical  Journal  and  Pharmacist,  July  26, 
