560  Syrup  of  Wild  Cherry.  {^""'noTis^s*'*™* 
The  Pharmacopoeia,  recognizing  the  necessity  of  adding  a  preserva- 
tive to  the  syrup  of  wild  cherry,  resorted  to  glycerin.  It  is,  however, 
rather  late  in  the  day  to  employ  glycerin  for  that  purpose,  more  espe- 
cially when  so  sparingly  applied.  Five  per  cent,  of  glycerin  is  con- 
tained in  the  new  official  syrup,  but  it  is  safe  to  say  that  20  per  cent, 
would  not  suffice  in  any  case  where  there  is  a  well-marked  tendency  to 
fermentative  decomposition.  Alcohol  would  have  been  amply  suffi- 
cient at  4  per  cent.,  and  should  have  been  used.  The  writer  in  this 
instance  strongly  recommends  alcohol,  not  alone  for  its  simple  preserva- 
tive effect,  but  since  it  also  serves  another  important  purpose  with 
equal  efficiency. 
Several  years  since  the  writer  employed  an  odd  looking  sample  of 
bark  for  preparing  the  syrup,  and  found  that  little  if  any  cyanhydric 
acid  was  developed.  The  bark  possessed  bitterness  and  astringency  in 
moderate  degree,  and  w^as  therefore  kept  with  a  view  to  employ  it  in 
alcoholic  mixtures  containing  wild  cherry  as  one  of  the  ingredients. 
On  employing  this  bark  on  such  an  occasion  with  a  25  per  cent,  alcohol, 
cyanhydric  acid  was  quite  freely  developed.  This  rather  astonishing 
result  showed  that  a  moderate  proportion  of  alcohol  did  not  only  not 
check  the  generation  of  the  acid,  but  even  caused  its  appearance  where 
water  alone  had  been  powerless.  Whilst  glycerin,  under  such  circum- 
stances would  have  retarded  or  more  or  less  obstructed  the  production 
of  cyanhydric  acid,  it  would  not  have  obviated  the  fermentation. 
Subsequently  the  writer  applied  one-eighth  alcohol  in  preparing  the 
syru23,  and  found  that,  primarily,  it  prevented  all  deterioration,  and 
secondarily,  whilst  facilitating  the  production  of  cyanhydric  acid,  also 
yielded  a  clearer  and  generally  more  satisfactory  percolate.  Substi- 
tuting the  glycerin  in  the  official  process  by  alcohol,  the  formula  then 
becomes  modified  as  follows : 
Wild  cherry  in  No.  20  powder,  .  .  12  parts 
Sugar,  granulated,     .         .  .  .  60  " 
Alcohol,  sufficient,  or  .  .  .  4  " 
Water,  sufficient  to  make    .  .  .  100 
Mix  alcohol  and  water  in  the  proportion  of  1  part  of  the  first  and 
7  parts  of  the  latter  and  moisten  the  wild  cherry  with  6  parts  of  this 
mixture.  Pack  the  moistened  bark  firmly  into  a  glass  percolator  and 
pour  on  of  the  above  mixture  until  the  liquid  has  slowly  penetrated 
to  the  bottom  of  the  column.  Now  check  the  percolation  for  24 
hours  by  closing  the  exit.    On  resuming  the  operation  let  the  current 
