164  Notes  on  Proteid  Iron  Solutions.       { Am gggrm 
tion  of  sodium  citrate,  the  resultant  solution  being  perfectly  clear, 
with  a  rich  claret  color,  odorless  and  free  from  ferruginous  taste. 
Further,  this  solution  is  not  rendered  turbid  by  carbon  dioxide  or 
by  boiling.  These  points  prove,  I  think,  a  dilute  solution  of  sodium 
citrate  a  better  solvent  for  peptonized  iron  than  sodium  hydroxide, 
where  peptonized  iron  is  to  be  employed  in  solution. 
Solution  of  ferric  chloride  may  be  advantageously  employed  in 
place  of  the  more  expensive  oxychloride  solution  in  the  preparation 
of  peptonized  iron.  It  yields  a  product  which  is  not  only  more 
completely  but  more  quickly  soluble  in  either  sodium  hydroxide, 
sodium  citrate  or  hydrochloric  acid. 
I  have  been  unable  to  prepare  a  satisfactory  solution  of  pep- 
tonized iron  by  the  use  of  the  oxychloride  solution.  The  solution 
so  made  is  clear  only  by  strong  transmitted  light.  In  view  of  the 
above  facts,  which  are  supported  by  exhaustive  tests  covering  some 
four  months,  I  have  constructed  the  following  formula,  which  yields 
not  only  a  more  beautiful  and  more  palatable  product,  but  one  of 
perfect  stability  : 
Egg  albumen,  fresh   125  gtn. 
Hydrochloric  acid      .  15  c.c. 
Pepsin   1  gm. 
Sol.  ferric  chloride,  U.S. P.  8th  60  " 
Ammonium  hydroxide  48  c.c. 
Sodium  citrate  20  gm. 
Alcohol   .  -     100  c.c. 
Aromatic  elixir  100  " 
Tincture  vanilla  100  " 
Angelica  wine  100  " 
Sodium  hydroxide  
Water  q.  s. 
Dissolve  the  egg  albumen  in  2,000  c.c.  of  water,  add  the  hydro- 
chloric acid  and  the  pepsin  and  digest  at  400  C.  for  six  to  twelve 
hours,  or  until  the  solution  gives  no  precipitate  of  albumen  on  boil- 
ing. Filter.  Dilute  the  ammonium  hydroxide  with  an  equal  vol- 
ume of  water  and  add  the  resultant  solution  to  the  solution  of  ferric 
chloride  in  small  portions,  skaking  well  and  waiting  after  each 
addition  until  the  precipitate  which  is  formed  is  redissolved.  When 
all  has  been  added,  dilute  to  2,000  c.c.  Mix  the  two  solutions  thor- 
oughly and  add  sufficient  dilute  sodium  hydroxide  solution  (25  c.c. 
official  solution  to  100  of  water)  to  render  the  mixture  faintly  alka- 
