Am.  Jour.  Pharm.  ) 
Sept.,  1879.  J 
Researches  on  Albumin. 
467 
warming,  and  are  attacked  by  bromine  in  the  cold  with  formation  of 
HBr  and  an  acid  of  formula  CnH2n_1N03.  In  the  analysis  of  the  fixed 
residue  the  ratio  of  nitrogen  to  oxygen  is  never  rigorously  1 : 2,  but 
there  is  always  a  slight  excess  of  oxygen,  so  that  the  ratio  is  nearer 
1  :2'i  or  1  :2'3  ;  this  difference  indicating  the  presence  of  small  quan- 
tities of  non-nitrogenous  compounds  or  of  bodies  in  which  the  atomic 
relation  of  nitrogen  to  oxygen  is  greater  than  1:2.  A  careful  exami- 
nation for  such  bodies  among  the  crystalline  deposits  resulted  in  the 
detection  of  a  few  grams  of  an  acid  from  1  kilogram  of  albumin,  offer- 
ing a  composition  very  close  to  that  of  glutamic  acid,  C5H9N04,  and  a 
smaller  quantity  of  a  second,  whose  composition  was  that  of  glutamic 
acid  minus  water,  C5H7NOs,  which  has  been  called  glutimic  acid. 
Judging  from  their  amount,  these  acids  play  but  a  secondary  part  in 
the  constitution  of  the  mixture  resulting  from  the  decomposition  of 
albumin;  the  acids,  on  the  other  hand,  which  are  capable  of  being 
extracted  in  reasonable  quantity  from  the  insoluble  barium  salts  do 
not  exhibit  a  constant  composition;  they  appear  to  be  residues  of  a 
.progressive  decomposition,  and  to  be  susceptible  of  being  resolved  by 
the  continued  action  of  baryta  into  a  mixture  of  leucines  and  oxalic  acid. 
Without  following  all  the  steps  by  which  the  author  succeeded  in 
tracing  the  presence  of  the  various  bodies  which  are  met  with  in  small 
proportions  as  constituents  of  the  fixed  residue,  and  modify  slightly  the 
ratio  between  the  nitrogen  and  oxygen,  we  may  sum  them  up  as 
follows  :  1.  Traces  of  succinic  and  lactic  acids.  2.  Tyrosin.  3. 
Amido-acids  of  the  type  of  CnH2n_1N02  glutamic  and  aspartic  acids. 
4.  Amido-acids  of  the  type  CnH2u_3N03  glutimic  acid.  5.  Amido- 
acids  of  the  types  CmH2m_4N206  and  CnH2n_1N03.  6.  Intermediate 
compounds  of  the  type  CmH2mN205. 
The  principle,  which  is  the  most  constant  among  the  products  of 
the  decomposition,  and  whose  proportion  is  the  most  easy  to  determine 
on  account  of  its  sparing  solubility,  is  tyrosin.  The  maximum  quan- 
tity obtained  of  this  body  was  3*5  per  cent.  ;  if,  therefore,  one  mole- 
cule of  albumin  reacts  in  the  formation  of  one  molecule  of  tyrosin, 
it  points  to  the  approximate  molecular  weight  5,500  for  the  former, 
since  I^1  =3*3.  An  expression  of  the  form  C240  H387N65O75S3  cor- 
responds with  a  molecular  weight  equa    to  5,473,  which  satisfies  the 
