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ON  PREPARED  CITRATE  OF  MAGNESIA. 
ON  PREPARED  CITRATE  OF  MAGNESIA. 
By  Charles  Ellis. 
The  article  which  is  the  subject  of  this  notice  is  called  Pre- 
pared Citrate  of  Magnesia,  to  distinguish  it  from  the  soluble 
citrate,  an  account  of  which  will  be  found  in  the  American 
Journal  of  Pharmacy,  vol.  xxiv.  page  115,  by  Edward  Parrish. 
Citrate  of  magnesia  has  within  a  comparatively  short  period  of 
time  been  introduced  into  very  general  use.  It  is  so  destitute  of 
bitterness  or  unpleasant  taste  that  its  preference  as  an  aperient 
medicine  over  the  nauseous  potion  of  epsom  salts  is  readily 
accounted  for. 
The  liquid  citrate  which  is  so  favorite  a  remedy  with  physi- 
cians, whenever  a  saline  cathartic  is  indicated,  is  one  of  the  most 
eligible  preparations  of  its  kind  yet  introduced  to  the  notice  of 
the  faculty.  It  is  in  consequence  of  its  popularity  that  enquiries 
have  been  made  for  an  article  of  similar  properties  in  poivder. 
To  render  the  "  soluble  citrate  "  pleasant  to  the  taste  and 
capable  of  forming  an  effervescing  solution  when  dissolved  in 
water,  it  is  necessary  to  pombine  with  it  sugar,  and  either  bicar- 
bonate of  soda  or  potash,  with  the  requisite  quantity  of  citric  or 
tartaric  acid  to  decompose  the  latter. 
If  citric  acid  be  used,  care  must  be  observed  to  dry  it  over  a 
water  bath,  so  as  to  deprive  it  of  water  of  crystallization,  previous 
to  its  combination  with  the  alkaline  bicarbonates. 
The  prepared  citrate  of  magnesia  is  not  recommended  as  equal 
to  the  solution,  because  the  citrate  in  powder,  however  carefully 
prepared,  is  only  slowly  soluble  in  cold  water,  and  does  not 
readily  make  a  clear  solution. 
When  such  a  preparation,  however,  is  wanted,  the  following 
formula  is  submitted  as  having  been  found  in  practice  to  answer 
the  desired  purpose. 
The  soluble  citrate  used  is  that  made  by  the  formula  published 
in  a  previous  volume  of  this  Journal,  and  referred  to  in  the  first 
part  of  this  notice. 
Take  Magnesise  citras,  giv. 
Sacchari  pulv.,  .Iviij. 
Acid  citric,  vel  tartaric,  pulv.,  *iiss. 
Soda  bicarb.,  Siij. 
01.  Limonis,  gtt.  xx. 
