242  Infusion  of  Wild  Cherry  Bark.  {kMjJTi,w™ 
a  glass  percolator.  Mix  the  glycerin  with  ten  fluidounces  of  water 
at  the  temperature  of  86°,  and  gradually  pour  the  mixture  upon  the 
bark,  and  when  it  has  all  passed  from  the  surface  continue  the  perco- 
lation with  water  until  one  pint  of  infusion  is  obtained. 
In  the  above  formula  I  have  refrained  from  mixing  glycerin  with 
that  portion  of  the  water  with  which  the  bark  is  moistened,  lest  it 
might  possibly  interfere  with  or  retard  its  reaction  upon  the  bark. 
As  prepared  by  the  above  formula,  the  infusion  is  much  darker  in 
color  than  that  as  made  by  the  officinal  process,  and  much  more  bitter  ; 
the  taste  of  which,  however,  is  modified  and  rendered  more  agreeable 
by  the  glycerin  it  contains.  The  hydrocyanic  acid  odor  is  also  strongly 
marked  in  it. 
I  think  that  the  formula  for  this  infusion  might  be  still  further 
improved  by  doubling  the  strength  of  the  infusion,  that  is,  using  one 
troyounce  of  bark  to  the  pint  of  infusion  instead  of  half  a  troyounce 
as  is  now  employed.  I  can  see  no  possible  objection  to  such  a  change, 
but  can  see  many  reasons  why  it  should  be  made.  It  would  greatly 
lessen  the  bulk  of  the  dose,  which  is  a  large  draught  for  a  delicate 
person  to  swallow.  The  dose  may  then  be  reduced  from  two  or  three 
fluidounces  to  two  or  three  tablespoonfuls. 
In  the  course  of  my  experiments  to  test  the  relative  merits  of  the 
above  formula  and  process  with  those  of  the  officinal,  I  made  upon 
several  occasions  a  sample  of  the  infusion  as  directed  in  the  above 
formula,  also  one  by  the  same  process,  but  doubling  the  quantity  of 
the  bark,  and  another  strictly  in  accordance  with  the  officinal  for- 
mula. 
The  sample  on  each  occasion  made  by  the  above  formula  kept, 
without  apparent  change  in  sensible  properties,  for  about  ten  days, 
with  the  exception  of  very  slight  turbidity  and  a  little  deposit  of  resin- 
ous or  other  insoluble  matter,  which  was  of  no  consequence.  The 
characteristic  hydrocyanic  acid  odor,  however,  remained  apparently 
undiminished  for  that  period,  after  which  I  could  perceive  a  gradual 
loss  of  this  odor,  with  an  increased  cloudiness  and  deposit ;  while 
the  sample  made  by  the  same  formula,  with  double  the  proportion 
of  the  bark  (one  troyounce  instead  of  half  a  troyounce  to  the  pint), 
kept  without  visible  change,  beyond  a  slight  cloudiness  and  a  little 
deposit,  for  about  sixteen  days,  retaining  its  characteristic  odor 
and  taste  but  very  slightly  diminished  for  that  time.  But  the  sample 
on  each  occasion,  which  was  made  in  strict  conformity  to  the  officinal 
