342 
Infusion  of  Digitalis. 
/Am.  Jour.  Pharm. 
t       July,  1889. 
though  having  the  same  specific  gravity  as  the  latter,  they  contain  a 
relatively  larger  percentage  of  active  solids,  because  the  latter  hold 
more  coloring  matter  in  solution,  and  as  both  exhibit  the  same  amount 
of  dissolved  solids  it  must  then  contain  a  smaller  quantity  of  the 
colorless,  active  ingredients.  This  belief  is  confirmed  in  the  observa- 
tions of  M.  Roger1,  who  found  that  "  the  toxicity  of  digitalis  dimin- 
ishes very  notably,  when  the  product  of  maceration  is  concentrated  by 
the  water-bath.  Then,  a  5  per  cent,  maceration,  which  is  toxic  in 
doses  of  0*05  gm.,  no  longer  kills  save  in  doses  of  1*8  gm.,  when  it  is 
concentrated  by  4  per  cent.  If  reduced  by  6'6  per  cent.,  3  gm.  would 
be  required  to  produce  the  same  effect."  These  experiments  would 
then  indicate  that  the  use  of  heat  and  boiling  water,  in  the  preparation 
of  the  infusion,  should  be  avoided,  for  the  reasons  that  the  constitu- 
ents of  the  leaf  are  altered  in  chemical  composition ;  the  active  in- 
gredients being  changed  to  non- toxic,  inactive  ones,  whilst  the  non- 
active  coloring  matter  is  rendered  more  soluble. 
In  the  previous  experiments,  the  specific  gravity  of  the  finished 
product  (made  from  one  drachm  of  No.  80  digitalis  powder  to  the 
pint)  was  1*00154 ;  showing  0*7  grains  of  dissolved  solids  in  each 
fluidounce  of  the  infusion.  Eight  more  samples  were  now  made, 
double  this  strength,  with  cold  water  and  with  boiling  water,  each, 
and  macerated  for  one,  two,  three  and  four  hours  ;  using  the  same 
digitalis  as  previously.  The  results  were  all  alike  (sp.  gr.  1  '00308), 
indicating  1*4  gm.  of  dissolved  solids  in  each  fluidounce. 
It  became  of  interest  in  this  connection,  to  see  just  how  far  this 
regularity  of  increase  of  dissolved  solids  would  go,  and  fourteen  infu- 
sions of  the  same  sample  of  powdered  (No.  80)  digitalis  as  previously 
used,  were  made  of  different  strengths.    The  results  are  these  : 
Grains  to  pint,  60,120,  130,  140,  160,180,  200,  240,300,  360,  420,  480,720,960. 
Solids  in  fl.oz.,  7,  1*4,  r54,l'68, 189,  2  1,  2*38,  2'52,2-95,  3'51,4'07, 4-50, 6.35,  8-15. 
The  regularity  of  increase  seems  to  be  reached  with  200  grains  to 
the  pint ;  above  that  point  the  increase  is  variable. 
Infusions  of  the  whole  leaf  were  now  made,  taking  ten  different 
samples  (120  grains  to  the  pint,  cold  water,  two  hours'  maceration, 
etc.).  With  singular  unanimity  they  all  showed  the  same  specific 
gravity  1*00308,  indicating  1*4  gm.  of  solids  to  the  fluidounce,  a  re- 
markable constancy  in  the  amount  of  solids  dissolved. 
1  Toxic  Power  of  Digitalis  ;  Nouv.  Rem.,  Feb.  24, 1889  ;  vide  Amer.  Jour.Phae. 
1889,  p.  174. 
