10 
ON  LIQUOK  FERRI  PERACETATIS. 
may  be  completely  decomposed  by  exposing  it  to  the  boiling 
temperature. 
Finally,  the  finished  preparation  must  be  protected  against 
too  strong  a  light  as  well  as  against  too  high  or  too  low  a  temp- 
erature, and  against  the  frequent  access  of  the  atmosphere.  The 
solutions  of  all  acetates  are  prone  to  change  in  contact  with  the 
air,  and  this  change  is  hastened  by  the  influence  of  light.  On 
the  other  hand  peroxide  of  iron,  when  in  solution  together  with 
many  organic  compounds  will  readily  be  reduced  to  protoxide, 
more  rapidly  if  light  has  free  access  to  it  or  is  aided  by  heat. 
If  these  precautions  in  regard  to  manipulation  and  preserva- 
tion are  observed,  the  solution  may  be  kept  for  a  very  long  time 
without  apparent  change. 
The  preparation  may  be  considered  pure  arid  correct  if  aside 
from  the  amount  of  acetic  acid  and  of  iron,  it  answers  to  the  fol- 
lowing tests  : 
Diluted  with  water  it  does  not  produce  a  precipitate  with 
chloride  of  barium, — absence  of  sulphuric  acid. 
Acidulated  with  nitric  acid,  nitrate  of  silver  occasions  no  pre- 
cipitate,— absence  of  chlorides. 
Diluted  and  precipitated  by  an  excess  of  ammonia,  the  filtrate 
is  colorless  and  leaves  no  solid  residue  on  evaporation, — absence 
of  some  metals,  acids  and  the  fixed  alkalies  and  alkaline  earths. 
Acidulated  with  muriatic  acid  and  deoxidized  by  sulphurous 
acid  or  an  alkaline  sulphite,  the  colorless  solution  is  not  dis- 
turbed on  the  addition  of  hydrosulphuric  acid — absence  of  the 
heavy  metals. 
The  dose  of  this  preparation  is  from  three  to  ten  drops,  usually 
largely  diluted  with  water,  sweetened  water  or  wine. 
It  is  employed  in  the  preparation  of  tinctura  ferri  acetatis 
cetherea,  which  is  composed  of  nine  parts  (by  weight)  of  the 
liquor,  two  parts  of  alcohol  sp.  gr.  -83,  and  one  part  of  acetic 
ether. 
This  is  the  tinctura  ferri  s.  nervina  Klaprothii  or  sether  aceticus 
ferratus  Klaprothii,  which  is  an  agreeable  preparation,  much  more 
acceptable  to  a  delicate  stomach  than  the  liquor ;  it  contains  six 
per  cent,  of  iron  and  is  given  in  doses  from  ten  to  sixty  drops 
several  times  daily,  usually  combined  with  cinnamon  water  or 
some  other  aromatic. 
