422  Digitalin.  [  Am-AJu°^1^2arm- 
gluconate  (C6Hn07)2Ba  -f-  Sr^O.1  A  calcium  salt  prepared  from  it, 
corresponded  in  all  respects  with  ordinary  calcium  gluconate.  The 
lactone  prepared  according  to  the  directions  of  E.  Fischer2  from  the 
calcium  salts  gave  the  dextro  rotation  corresponding  to  d-gluconic 
acid,  and  hence  it  may  be  inferred  that  in  the  transformation  of 
digitalin  grape  sugar  is  produced. 
On  the  basis  of  the  assumption,  already  referred  to  as  being 
probably  correct,  that  the  composition  of  digitaligenin  is  repre- 
sented by  the  formula  Cf6H^02,  the  following  equation  is  obtained : 
C16H2A  -  C6H1206  +  C7Hu05  —  H20  =  C^H^O^  and  a  formula 
for  digitalin  C29H^012  which  differs  only  by  CH2  from  C^N^O^  = 
6  X  QH802  or  that  indicated  by  the  results  of  analysis-  of  the 
glucoside.  Whether  that  is  really  the  correct  expression  of  the 
molecular  weight  of  the  substance  must  be  determined  by  other 
experiments. 
However,  it  is  sufficiently  evident  from  the  facts  above  stated  that 
digitalin  is  to  be  regarded  as  having  chemical  individuality,  not- 
withstanding the  want  of  capability  to  crystallize.  It  follows  that 
its  physiological  action  must  be  constant,  as  distinguished  from  ihe 
varieties  of  commercial  digitalin,  hitherto  known,  which  have  been 
mixtures  of  the  active  and  inactive  constituents  of  digitalis,  in 
variable  proportions  which  rendered  any  safe  adjustment  of  dose 
impracticable. 
In  the  pharmacological  trial  of  digitalin  Professor  Boehm  has 
made  the  following  observations  : 
Digitalin  administered  to  frogs  in  doses  of  05  milligramme 
produces  systolic  steppage  of  the  heart  after  15  to  20  minutes. 
Increase  in  the  volume  of  the  heart  pulse  could  not  be  detected  by 
means  of  the  Williams  Dresser  apparatus,  even  when  the  doses 
were  very  carefully  administered. 
Intravenal  injection  of  2  milligrammes  produced  in  dogs  increase 
of  blood  pressure  with  reduction  of  the  frequency  of  the  pulse  and 
increase  of  its  volume.    By  increasing  the  dose  to  4  milligrammes 
1  The  air-dry  barium  gluconate  should  theoretically  lose  9/29  per  cent,  in 
drving,  but  the  salt  obtained  gave  only  8*17,  and  this  was  found  to  be  the  case 
also  with  barium  gluconate  (8*07).  Herzfeld  {Annalen,  220,  335)  obtained 
similar  results  by  heating  barium  gluconate  to  ii5:  C.  By  an  error  of  calcula- 
tion he  gives  as  the  theoretical  amount  of  water  8*13  per  cent. 
2  Berichte,  xxiii,  2615. 
