Am.  Jour.  Pharm.  | 
Jan.,  1881.  j 
Syrups  by  Percolation. 
3 
the  Pharmacist/'  of  Chicago)  about  the  preparation  of  syruys  by 
percolation,  and  thought  the  idea  capital.  The  process  was  tried  at 
the  first  opportunity  with  simple  syrup.  The  percolator  was  charged, 
as  usual,  with  a  wad  of  cotton  in  the  neck,  a  cork  in  the  orifice,  loaf 
sugar  and  water,  adjusted  on  a  filtering  stand,  and  set  aside  until  the 
sugar  had  all  been  disintegrated  and  settled.  TJie  cork  was  then 
removed,  and  it  was  expected  that  percolation  would  proceed  without 
.any  trouble;  but  it  did  not.  Having  obtained  2  fluidounces  of  syrup 
in  12  hours  the  process  was  discontinued  and  the  syrup  finished  by 
boiling.  Using  cotton  wads  for  the  percolation  of  syrups  was  found 
an  utter  failure.  In  subsequent  operations  sponge  wads  were  substi- 
tuted, and  with  entire  success.  A  piece  of  common  close,  soft  sponge 
is  trimmed  to  a  cone  shape,  ^,  1  inch  or  longer,  and  1,  2  or  more 
inches  diameter.  The  sponge  is  thoroughly  washed  and  while  still 
moist  placed  in  position  in  the  neck  of  a  percolator,  funnel  or  other 
suitable  vessel  by  slightly  compressing  it.  Sponges  with  small  pores 
need  little  and  such  with  large  pores  need  more  compression  in  adjust- 
ing. If  it  is  placed  too  loose  the  syrup  will  pass  too  fast  and  not  suf- 
ficiently clear,  if  placed  too  tight  the  syrup  will  pass  too  slow  or  not 
at  all.  The  proper  amount  of  compression  is  reached  when  the  pores 
of  a  close  sponge  1  inch  long  and  J  inch  in  diameter  are  closed  in  such 
a  manner  by  adjustment  in  a  f  inch  necked  common  half-gallon  glass 
percolator  that  one  pint  of  syrup  will  percolate  in  an  hour.  Accord- 
ing to  the  size  of  the  sponge,  its  compression,  the  size  of  the  neck  of 
the  percolator,  and  its  capacity,  less  or  a  great  deal  more  may  be 
obtained.  When  definite  quantities  of  syrups  are  made,  towards  the 
end  of  the  process  the  sugar  must  be  heaped  towards  the  centre  of  the 
percolator,  because,  since  the  process  of  displacement  progresses  faster  in 
the  centre  over  the  orifice  than  at  the  circumference  of  the  percolator, 
the  sugar  is  dissolved  fastest  there,  and  when  dissolved  down  to  the 
sponge  allows  the  menstruum  to  pass  without  dissolving  the  balance. 
In  a  continuous  process  this  precaution  is  unnecessary.  By  percola- 
tion, when  properly  conducted,  syrups  are  obtained  absolutely  clear, 
just  as  if  filtered  through  paper. 
Some  of  the  syrups  of  the  Pharmacoooeia  cannot  be  prepared  by 
any  other  than  the  cold  process,  for  instance  syrupus  allii,  syrupus 
pruni  virginianse,  and  with  these,  as  also  with  fruit  syrups,  percola- 
tion may  be  considered  the  ne  'plus  ultra  of  perfection.  In  most  of  the 
syrups  of  the  Pharmacopoeia  filtration  can  be  combined  with  percola- 
