ON  SYEUP  OP  CITRIC  ACID  OF  THE  PHARMACOP(EIA.  393 
raainder,  or  enough  to  make  the  filtrate  measure*  ahout  seven 
pints  and  a  half.  Lastly,  add  the  laudanum  and  benzoic  acid 
to  the  filtered  liquid,  in  a  bottle,  and  shake  until  the  acid  is 
dissolved. 
ON  SYRUP  OF  CITRIC  ACID  OF"  THE  PHARMACOPCEIA. 
Mr.  Editor  : 
Sir^ — Your  earnest  request  in  a  late  number  of  the  ^'Journal  " 
for  each  and  all  to  contribute  something  for  the  consideration  of 
the  committee  of  revision  for  the  next  edition  of  the  Pharmaco- 
poeia, has  induced  me  to  ofier  the  following : 
In  the  process  for  syrup  of  citric  acid  of  the  Pharmacopoeia  of 
1860,  it  directs  to  "  rub  the  citric  acid  and  the  oil  of  lemon  with 
a  fluidounce  of  the  syrup,  then  add  the  mixture  to  the  remainder 
of  the  syrup,  and  dissolve  with  a  gentle  heat."  This  involves 
the  use  of  a  fire, — often  not  at  hand, — also  the  soiling  of  capsule 
and  mortar.  The  capsule  ordinarily  used  in  the  shops  for  such 
purposes  being  much  larger  than  is  necessary,  causing  the  loss 
of  more  or  less  of  the  material ;  also  in  the  use  of  the  mortar. 
Beside  this,  the  time  nec2ssary  is  quite  an  item. 
As  a  substitute  for  the  officinal  manipulation,  I  would  suggest 
that  the  citric  acid  and  oil  of  lemon  be  rubbed  together  in  a 
mortar,  then  added  to  the  required  amount  of  syrup  in  a  bottle  in 
which  it  is  intended  to  be  kept,  and  well  shaken.  Set  aside,;  in 
a  short  time  the  citric  acid  will  be  found  to  have  entirely  dis- 
solved, making  a  preparation  fully  equal  in  appearance  to  the 
officinal,  and  which  has  the  advantage  of  "being  marked  for  the 
simplicity  and  directness  of  its  manipulation." 
Yours,  &c.,  Joseph  Harrop. 
Leavenworth,  Kansas,  July  29,  1869. 
CRITICAL  NOTE  ON  PERMANGANATE  OF  POTASSA  AS 
A  TEST  FOR  DISTINGUISHING  CHLORINE,  BROMINE 
AND  IODINE. 
By  George  McDonald. 
In  several  chemical  journals  there  has  recently  appeared  an 
**Tlie  variable  consistence  of  the  honey  will  alter  the  result  very 
slightly. 
