^i^S^T'}  Syrup  of  Ferrous  Iodide.  \o9 
obtained  from  different  establishments,  in  regard  to  purity,  efflorescence 
and  amount  of  water  of  crystallization,  that  I  have  purified  and 
recrystallized  this  salt,  much  to  my  satisfaction,  and  it  will  fully  repay 
pharmacists  to  adopt  the  following  plan  : 
Dissolve  the  large  crystals  of  common  sal  soda  in  pure  water,  allow 
all  the  insoluble  impurities  to  subside,  filter  this  solution  and  evaporate 
at  a  moderate  heat  till  a  pellicle  forms  over  the  surface  of  the  liquid, 
and  set  aside  for  two  or  three  days  to  crystallize.  A  small  proportion 
of  mother  liquor  remains,  which,  if  sufficiently  pure,  may  be  still 
farther  evaporated  and  crystallized,  if  desired.  These  crystals  should 
now  be  dried  on  a  linen  strainer  in  a  moderately  warm  air-chamber, 
much  care  being  necessary  in  this  operation,  as  the  crystals  effloresce 
readily  in  the  atmosphere,  and  too  much  heat  will  easily  liquify  the 
salt  again.  This  process  yields  beautiful,  clear,  oblique-rhombic, 
prismatic  crystals,  which  should  be  preserved  in  well-stopped  jars.  It 
may  contain  some  sodium  chloride  and  sulphate,  which,  however,  if 
in  minute  quantity  only,  do  not  detract  from  its  medicinal  value. 
An  effervescing  granular  salt  of  sodium  tartrate  may  be  formed  by 
heating,  on  a  sand  bath,  anhydrous  sodium  carbonate  and  pure  pow- 
dered tartaric  acid,  in  the  proportion  of  three  parts  of  the  alkali  to  four 
and  a  quarter  of  the  acid.  Care  must  be  taken  to  do  this  in  a  vessel 
not  affected,  chemically,  by  tartaric  acid,  and  to  keep  the  chemicals 
well  stirred  and  scraped  up  from  the  bottom,  or  they  will  become  yel- 
low and  carbonized.  This  gives  an  agreeable,  slightly  acid  salt,  very 
•soluble  in  water,  which  solution  effervesces  briskly,  and  forms  a  conve- 
nient and  pleasant  cathartic  and  cooling  drink.  This  preparation 
keeps  well  and  does  not  attract  moisture,  as  do  many  effervescing 
granular  salts. 
For  a  cooling  drink  the  solution  may  be  taken  in  tablespoonful 
doses  hourly,  as  a  mild  cathartic  one  half  a  bottleful  and  for  a  brisk 
purge  a  whole  bottleful.  The  granular  salt  may  be  taken  in  teaspoon- 
ful  or  tablespoonful  doses,  dissolved  in  sweetened  water. 
THE  EFFECT  OF  LIGHT  ON  SYRUP  OF  THE  IODIDE  OF  IRON. 
BY  CLEMMONS  PARRISH,  PH.G. 
My  attention  was  called,  in  making  syrup  iodide  of  iron,  U.  S.  P., 
to  a  change  occurring  in  the  same  lot  under  different  circumstances. 
The  syrup  was  made  in  accordance  with  the  officinal  process,  care 
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