ON  CITRATE  OF  MAGNESIA. 
121 
ON  THE  PREPARATION  OF  CITRATE  OF  MAGNESIA. 
By  "William  J.  Watson. 
Editor  of  the  American  Journal  of  Pharmacy  : 
Dear  Sir, — In  the  preparation  of  Citrate  of  Magnesia  by 
the  formula  of  the  Pharmacopoeia,  I  have  always  failed  to  obtain 
a  permanent  solution  ;  and  all  the  druggists  whom  I  have  con- 
sulted give  the  same  report. 
The  following  formula,  which  I  have  adopted  and  by  which 
I  have  prepared  the  citrate  for  about  two  years,  gives  a  prepa- 
ration which,  though  not  so  active  as  the  solution  of  the  Phar- 
macopoeia, acts  thoroughly  as  a  purgative  when  the  contents  of 
a  bottle  are  taken  fasting,  is  pleasantly  acid,  contains  a  large 
quantity  of  carbonic  acid  gas,  and  does  not  produce  griping,  as 
the  solution  containing  Bicarbonate  of  Potassse  is  said  to  do ; 
and  will,  if  tightly  corked,  remain  without  change  or  deposit  for 
an  indefinite  time. 
Acid  Citric, 
Magnesia  Carb.    (The  form  known  as  small  squares.) 
Syr.  Simplex, 
01.  Limonis, 
Aqua,  {la  q.  s. 
Take  six  twelve  ounce  citrate  bottles,  (to  each  of  which  has 
been  fitted  a  good  velvet  cork,  previously  macerated  in  boiling 
water  for  half  an  hour),  add  to  each  bottle  01.  Limonis  gtt.j,  Syr. 
Simplex  ^iss. ;  weigh  out  six  separate  portions  of  Acid  Citric, 
5iv.  each,  six  of  Magnesia  Carb.,  ^iij.  each,  and  six  of  Acid 
Citric,  ^ij.  each  ;  put  into  a  mortar  one  of  the  portions  of  Mag- 
nesia Carb.  and  one  of  the  ^iv.  portions  of  Acid  Citric,  rub  to- 
gether with  sufficient  water  (about  six  ounces)  to  make  a  smooth 
mixture,  and  add  to  one  of  the  bottles,  proceed  in  the  same 
manner  with  the  remainder ;  (commencing  with  the  first  bottle 
to  which  the  solution  was  added,)  add  one  of  the  sij.  portions  of 
Citric  Acid  to  each,  fill  up  with  Aqua,  cork  and  tie  down,  place 
the  bottle  on  its  side  for  half  an  hour,  shaking  occasionally. 
By  this  process  the  solution  of  Citrate  of  Magnesia  is  not  fil- 
tered, and  to  insure  a  handsome  preparation  the  water  should 
