Aui.  Jour.  Pharm.  ) 
February,  1915.  / 
Arsenic  Antidote. 
6] 
The  Committee  of  Revision  has  decided  to  follow,  in  the  ninth 
revision  of  the  U.  S.  Pharmacopoeia,  the  present  official  process  for 
making  "  Ferric  Hydroxide  with  Magnesium  Oxide,"  but  will  re- 
verse the  order  of  mixing  the  iron  and  magnesia. 
Mr.  Raubenheimer  suggests  the  following  formula: 
Solution  of  ferric  sulphate  ;  .    40  Cc. 
Magnesia  magma  (milk  of  magnesia)  .  .  .  300  Cc. 
Water,  a  sufficient  quantity. 
Mix  40  Cc.  of  solution  of  ferric  sulphate  with  260  Cc.  of  water 
in  one  bottle,  and  mix  300  Cc.  of  magnesia  magma,  or  milk  of  mag- 
nesia, with  300  Cc.  of  water  in  another  bottle  having  the  capacity 
of  1000  Cc.  When  the  antidote  is  required,  add  the  iron  solution 
gradually  to  the  magnesia  mixture,  shake  well,  and  the  preparation 
is  ready  for  instant  use. 
Using  wine  measure,  it  will  be  found  convenient  to  keep  1%. 
fluidounces  of  solution  of  ferric  sulphate  diluted  with  8^4  fluid- 
ounces  of  water  in  one  bottle,  and  10  fluidounces  of  magnesia  magma 
previously  mixed  with  10  fluidounces  in  water  in  a  second  bottle, 
having  the  capacity  of  one  quart. 
The  advantages  claimed  for  the  preparation  made  by  this  method 
are: 
1.  The  finely-suspended  magnesium  hydroxide  in  the  milk  of 
magnesia  forms  a  smooth  and  finely-divided  magma  of  ferric 
hydroxide. 
2.  Such  a  magma  unquestionably  has  therapeutic  advantages  in 
combining  more  readily  with  the  arsenic. 
3.  By  pouring  the  iron  solution  into  the  diluted  milk  of  mag- 
nesia a  more  voluminous  magma  will  be  obtained  than  by  the  reverse 
as  directed  in  the  U.  S.  Pharmacopoeia. 
4.  Milk  of  magnesia,  if  properly  prepared,  is  practically  free 
from  carbonate,  while  magnesium  oxide  always  contains  some  car- 
bonate, except  when  recently  calcined. 
It  has  been  suggested  to  the  Committee  of  Revision  that,  if  the 
present  official  formula  for  the  preparation  be  retained,  an  alterna- 
tive process  of  using  magnesia  magma  instead  of  magnesium  oxide  be 
authorized  in  the  next  revision  of  the  Pharmacopoeia. 
