AmseXSarm-}      Tinctures  from  Fluid  Extracts.  443 
strengths  of  menstrua  for  the  tinctures  and  corresponding  fluid 
-extracts  is  of  interest : 
Name  of  Drug. 
Menstruum  for  Tincture. 
Menstruum  for  Fluid 
Extract. 
(parts.) 
(parts.) 
A  1, 
W  1. 
A  3i 
W  1. 
A  1, 
W  1. 
A. 
A  1, 
W  1. 
A3, 
W  1. 
A  1, 
W  1. 
A3, 
W  1. 
1?  Vl  11  V\o  rY\ 
A  1, 
W  1. 
'  A3, 
W  1. 
A  1, 
W  1. 
A3, 
W  1. 
A  1, 
W  1. 
A3, 
W  1. 
Cubeb,  
A  1, 
W  1. 
A. 
A  2, 
W  1. 
A. 
Squill,  
A  1, 
W  1. 
A. 
Colchicum  Seed,  
A  1, 
W  1. 
A  2, 
W  1, 
A  1, 
W  1. 
A  2, 
W  1. 
A,  Alcohol ;  W,  Water. 
From  this  table  it  will  be  seen  that,  in  the  cases  mentioned,  much 
more  strongly  alcoholic  menstrua  are  used  for  fluid  extracts,  than 
are  directed  for  corresponding  tinctures ;  and  this  must  result  in  a 
certain  relative  difference  between  the  two  preparations. 
A  good  illustration  of  the  changes  attendant  upon  a  difference  of 
menstrua,  may  be  found  in  digitalis  infusion.  It  is  now  accepted 
that  the  most  important  proximate  constituents  of  digitalis  leaves 
are  Schmiedeberg's  digitalin,  with  digitoxin,  digitonin  and  digitalein. 
These  may  be  grouped  into  two  classes  according  to  solubility. 
First,  those  soluble  in  alcohol  and  insoluble  or  almost  insoluble 
in  water ;  second,  those  soluble  in  both  alcohol  and  water. 
Digitoxin  and  digitalin  belong  to  the  first  group,  and  digitonin  and 
digitalein  belong  to  the  second  group.  It  will  be  seen  that  the 
tincture  and  fluid  extract  contain,  most  largely,  digitoxin  and 
digitalin  with  some  digitonin  and  digitalein,  whilst  the  infusion 
