244  Infusion  of  Wild  Cherry  Bark.  {^StSS* 
I  have  directed  in  the  above  process  a  two  hours'  preliminary  ma- 
ceration, instead  of  an  hour  as  in  the  officinal.  This  may,  even  with 
advantage,  be  prolonged  to  five  or  six  hours,  when  circumstances  will 
permit,  so  time  will  be  given  for  the  necessary  reactions  which  develop 
the  sedative  properties  of  the  bark  to  become  more  complete. 
The  temperature  of  the  water  with  which  the  bark  is  moistened 
preparatory  to  maceration  should  never  be  below  86°  to  90°,  and  the 
maceration  should  be  conducted  at  about  the  same  temperature,  as 
this  temperature  serves  to  promote  the  reactions  referred  to  above. 
Yet  care  must  be  exercised  not  to  allow  the  temperature  to  much  ex- 
ceed that  point,  otherwise  there  will  be  more  or  less  loss  of  hydrocy- 
anic acid.  Attention  to  this  point  is  of  like  importance,  also,  in  the- 
manufacture  of  all  preparations  of  wild  cherry  bark  where  it  is  desir- 
able to  secure  its  full  sedative  power. 
Especially  is  this  necessary  in  cold  weather.  In  summer  the  water 
is  usually  warm  enough,  and  the  temperature  of  the  atmosphere  suck 
as  to  render  the  resort  to  artificial  warmth  unnecessary. 
Some  pharmacists,  when  making  the  syrup  of  wild  cherry  barka. 
after  moistening  the  bark  with  water  place  it  in  the  cellar  to  mace- 
rate ;  but  this  should  not  be  done,  as  most  cellars  are  too  cold  at  any 
season  for  this  purpose.  It  is  also  necessary  that  the  maceration  be 
conducted  in  an  air-tight  vessel,  otherwise  the  hydrocyanic  acid  will 
escape  almost  as  fast  as  it  is  generated.  There  is  another  precaution^ 
also,  that  it  is  well  to  observe  in  this  matter,  and  that  is  to  pack  the 
bark  rather  firmly  in  the  vessel  in  which  it  is  macerated,  as  this  will 
tend  to  confine  the  acid  and  prevent  its  waste. 
There  are  many  cases  of  disease  in  the  treatment  of  which  the 
physician  may  wish  to  combine  the  properties  of  tar  with  those  of 
wild  cherry  bark  ;  if  so,  an  elegant  and  valuable  combination  of  this 
kind  may  be  formed  in  the  following  manner : 
iy.    Tar,  pure,      .....    one  pint, 
Infusion  Wild  Cherry  Bark,    .       .    four  pints. 
To  the  infusion,  in  a  suitable  bottle,  or  other  air-tight  vessel,  add 
the  tar.    Set  it  aside  to  macerate  for  two  or  three  days.    Stir  the 
mixture  well  with  a  stick,  and  shake  it  vigorously  frequently  during 
the  maceration.    Then  filter  through  paper. 
The  stirring  directed  in  the  preparation  of  this  compound  infusion 
is  an  important  part  of  the  process,  as  it  breaks  up  the  tar  and  thus. 
