462 
Researches  on  Albumin. 
(  Am.  Jour.  Pharm. 
\      Sept.,  1879. 
RESEARCHES  ON  ALBUMIN. 
BY  SCHUTZENBERGER. 
It  having  been  observed  that  albuminoid  substances  when  submitted 
to  the  action  of  baryta  under  suitable  conditions  appear  to  be  trans- 
formed entirely  into  crystallizable  or  into  definite  principles,  it  seemed 
reasonable  to  suppose  that  a  carefully  conducted  and  complete  study  of 
this  reaction  would  be  likely  to  materially  contribute  to  a  knowledge  of 
the  proximate  composition  of  these  bodies,  if  it  did  not  ultimately  solve 
the  question  respecting  their  constitution. 
With  this  end  in  view,  the  author  instituted  and  has  carried  out  an 
extended  series  of  experiments  upon  the  action  of  baryta  solution  at 
high  temperatures  on  coagulated  egg-albumin  and  other  nitrogenous 
principles,  the  results  of  which  investigation  form  the  subject  of  the 
present  memoir. 
The  albuminoid  under  experiment  was  placed  with  the  alkaline  solu- 
tion in  an  iron  silver-lined  autoclave,  and  heated  to  a  definite  tempera- 
ture for  some  hours.  After  cooling,  the  contents  of  the  cylinder, 
consisting  of  an  amber-colored  liquid  and  a  solid  deposit,  were  trans- 
ferred to  a  large  flask,  and  the  ammonia  (1)  distilled  off  into  hydro- 
chloric acid  and  estimated  ;  the  residue  (2)  in  the  flask  was  brought 
upon  a  weighed  filter,  washed  with  boiling  water  until  the  baryta  was 
removed,  then  dried  and  weighed.  The  filtrate  from  the  latter  was 
precipitated  by  a  current  of  carbonic  anhydride,  the  barium  carbonate 
removed,  and  the  baryta  remaining  in  the  liquor  exactly  precipitated  by 
sulphuric  acid  and  its  weight  ascertained.  The  acid  thus  set  free, 
which  proved  to  be  acetic  acid  (3)  with  traces  of  formic  acid,  was 
distilled  ofF  in  a  vacuum  arid  again  determined.  The  residue  remain- 
ing from  the  distillation  of  the  acetic  acid,  which  the  author  terms 
fixed  residue  (4),  is  of  a  clear  yellow  color,  friable  and  easily  removable 
from  the  vessel  ;  it  contains  all  the  fixed  principles  such  as  leucine, 
tyrosine,  etc.,  which  are  formed  at  the  expense  of  the  organic  substance, 
in  the  proportions  in  which  they  are  produced. 
Determination  of  the  Ammonia. — Having  proved  that  coagulated 
albumin,  washed  with  ether  and  dried  at  1400,  contained  16*5  per  cent, 
of  nitrogen,  the  effect  of  boiling  it  with  three  times  its  weight  of  baryta 
under  ordinary  pressure  was  ascertained.  1*2  per  cent,  of  nitrogen 
was  evolved  in  the  form  of  ammonia  within  the  first  half  hour,  the 
disengagement  proceeding  slowly,  until  after  120  hours'  boiling  2*2  per 
