i8o 
Albuminate  of  Iron. 
f  Am.  Jour.  Pharz»„ 
\      April,  1880 
oxide.  The  same  preparation  may  be  obtained  by  precipitating  the 
solution  of  the  albuminate  of  iron  with  alcohol,  etc. 
As  mentioned,  my  first  practical  acquaintance  with  albuminate  of 
iron  was  with  the  solution  produced  by  the  formula  of  Dr.  Donitz. 
This  solution  is,  as  described  by  the  author,  a  perfectly  transparent 
light-brown  liquid,  nearly  tasteless,  and  will  keep  well  in  cool  weather 
for  several  weeks.  It  contains,  as  I  have  determined  by  calculation 
and  subsequent  experiments,  an  excess  of  albumen,  even  when  the 
smaller  quantity  of  egg-white  is  employed,  for  which  reason  the  latter 
quantity  was  adopted  for  the  experiments  made  with  this  solution. 
When  such  a  solution  is  evaporated  in  a  current  of  warm  air  a  light- 
brown,  transparent  residue  is  obtained,  which  may  be  detached  in  the 
form  of  scales,  and  readily  furnishes  a  powder  having  a  very  light  cin- 
namon-brown color.  This  dry  albuminate  also  corresponds  to  the 
description  of  Dr.  Donitz,  being  readily  dissolved  by  water  to  form  a 
clear  solution,  particularly  if  a  modicum  of  dilute  hydrochloric  acid  is 
added.  The  yield,  however,  is  necessarily  very  small,  owing  to  the 
dilute  character  of  the  solution;^  and  the  preparation  of  dry  albuminate 
from  such,  on  any  considerable  scale,  is  therefore  out  of  question;  and 
though  subsequent  experiments  showed  that  a  far  more  concentrated 
solution  of  albuminate  of  iron  could  be  obtained  by  a  modification  of  the 
method,  it  nevertheless  seemed  desirable  to  ascertain  some  process — if 
possible  one  of  precipitation — whereby  the  evaporation  and  consequent 
exposure  of  any  considerable  proportion  of  liquid  should  be  avoided. 
To  this  end,  it  became  necessary  to  subject  the  known  or  accepted 
characters  of  albumen  and  its  compounds  to  critical  review,  when,, 
among  others,  the  following  points  bearing  directly  upon  the  subject 
under  consideration  were  developed.^ 
I..  Albumen  is  not  precipitated  from  its  aqueous  solutions  by  ferric 
chloride,^  and  even  prevents  the  precipitation  of  the  oxide  of  that  metal 
by  alkalies. 
^Egg-white  contains  about  12-5  per  cent,  dry  albumen  (which  quantity  has  been 
accepted  by  me  in  my  experiments),  consequently  six  fluidounces  of  Donitz's  solu- 
tion will  yield  only  about  one  drachm  of  albuminate. 
The  principal  works  consulted  were  '*  Graham-Otto's  Lehrbuch  der  Chemie," 
"Organische  Chemie,"  vol.  iii,  by  H.  v.  Fehling,  and  "Dictionary  of  Solubilities 
of  Chemical  Substances,"  by  Frank  A.  Storer. 
This  does  not,  however,  apply  to  the  egg-white  in  its  natural  condition,  as  is 
evident  from  the  methods  hitherto  pursued  for  the  preparation  of  albuminate  of  iron. 
