AmMa0n""i87h7!rin' }      Solution  of  Citrate  of  Magnesium,  9 9 
I  would  suggest  to  the  Committee  on  Revision  of  the  "  U.  S.  Phar- 
macopoeia," that  it  would  be  much  more  convenient  for  physicians  and 
druggists  to  have  all  the  glycerites,  with  the  exception  of  the  glycerite 
of  tar,  made  of  this  definite  strength,  instead  of  the  present  plan  of 
ordering  two  troyounces  of  the  base  and  one-half  pint  of  glycerin, 
making  a  solution  of  which  no  one  can  know  the  exact  strength  with- 
out experimenting  to  see  how  much  increase  of  bulk  takes  place. 
If  the  strength  I  have  mentioned  be  adopted,  we  would  have  a  pre- 
paration, containing  in  any  number  of  minims,  one-fourth  as  many 
grains  of  the  base,  and  it  would  be  a  very  convenient  solution  to  use 
in  dispensing  small  quantities. 
Nitrate  of  bismuth  dissolves  readily  in  the  proportion  of  glycerin 
mentioned,  and  the  resulting  glycerite  can  be  diluted  with  a  small 
quantity  of  water  (an  equal  bulk  or  less),  and  yet  retain  all  the  bismuth 
in  permanent  solution. 
If  more  than  three  parts  of  water  be  added  to  one  part  of  the 
glycerite,  a  portion  of  the  bismuth  will  be  slowly  deposited.  The  length 
of  time  elapsing  before  the  precipitation  commences,  varying  according 
to  the  amount  of  dilution.  A  few  experiments  were  made  to  ascertain 
how  different  degrees  of  dilution  would  affect  it. 
One  part  of  glycerite  added  to  twelve  parts  of  distilled  water  (by 
measure)  commenced  to  precipitate  in  about  two  hours  ;  one  part  in 
eight  parts  of  water  in  four  hours ;  one  part  in  six  parts  of  water  in  twenty 
hours  ;  but  in  very  dilute  solutions  it  would  stand  much  longer,  as  one 
part  to  forty-eight  parts  of  water  stood  two  days  before  showing  any  signs 
of  precipitation. 
On  account  of  this  fact  of  precipitating  when  added  to  water,  the 
physician  should  always  prescribe  the  glycerite  of  bismuth,  and  direct 
the  patient  to  dilute  it  when  using  it.1 
ON  SOLUTION  OF  CITRATE  OF  MAGNESIUM. 
By  John  W.  Watts. 
The  formula  for  preparing  solution  of  citrate  of  magnesium,  as  laid 
down  in  the  "U.  S.  Pharmacopoeia,"  is  liable  to  a  series  of  objections, 
in  regard  to  preparation  and  preservation;  the  latter  objection  I  do  not 
think  can  be  overcome  by  the  present  formula  without  seriously  alter- 
'Compare  also  notes  on  the  same  prepare  tion,  on  page  89  of  February  number. 
— Editor. 
