Am.  Jour.  Pharm.  ) 
Sept.,  1879.  / 
Researches  on  Albumin. 
469 
which  leaves  C22lH3nN49058,  an  expression  which  corresponds  with  the 
type  CnH2tl_2NO  quite  as  nearly  (?)  as  that  of  the  fixed  residue  with  the 
type  CaH2nN02,  the  difference  on  both  sides  being  a  slight  excess  of 
oxygen.  The  molecule  of  albumin,  therefore,  resembles  that  of  a  body 
whose  formula  is  x(CmH2m_4N2Oj),  where  m— 2n,  and  undergoes 
hydration  in  two  distinct  steps.  At  ioo°,  with  a  limited  proportion  of 
baryta,  the  grouping  fixes  a  number  of  molecules  of  water  equal  to  one- 
half  the  number  of  atoms  of  nitrogen  which  it  contains,  and  becomes 
x(CmH2m_2N203).  The  latter,  at  a  higher  temperature,  can  in  its  turn 
fix  a  number  of  molecules  of  water  equal  to  the  number  of  atoms  of 
nitrogen  which  it  contains,  changing  itself  to  the  formula  x(CmH2mN204, 
the  final  result  being  the  assimilation  of  as  many  molecules  of  water  as 
the  albumin  contains  atoms  of  nitrogen.  Albumin  is  then  probably  an 
imi do -derivative,  which  by  hydration  changes  into  a  mixture  of  amido-deriva- 
tives. 
To  return  to  the  observed  relation  between  the  ammoniacal  nitrogen 
evolved  and  the  carbonic  and  oxalic  acids  produced,  it  is  noticeable 
that  two  molecules  of  ammonia  are  disengaged  for  each  molecule  of 
acid  generated.  The  simplest  reaction  which  could  account  for  such 
a  phenomenon  would  be  to  suppose  that  the  ammonia  results  from  the 
hydration  of  urea  or  cyanamideand  oxamide,a  supposition  which  acquires 
a  much  greater  degree  of  probability  when  it  is  shown  that  a  very  large 
majority  of  nitrogenous  principles,  when  similarly  decomposed,  yield  a 
quantity  of  ammonia  which  is  precisely  the  amount  that  should  be  fur- 
nished by  the  carbonic  and  oxalic  acids  produced  at  the  same  time, 
supposing  the  whole  to  result  from  the  reaction  above  mentioned.  The 
author  has  examined  wool,  hair,  ossein,  isinglass,  gelatin,  goat's  hair, 
silk,  fibrin  and  chondrin,  in  all  of  which  the  above  relations  held  good. 
Summary. — It  has  been  shown:  1.  That  the  mixture  of  fixed  prin- 
ciples derived  from  albumin  by  hydration  contains  only  amido-deriva- 
tives.  2.  That  these  derivatives  can  be  divided  into  two  unequal  por- 
tions, one,  the  weight  of  which  is  about  16  to  18  per  cent.,  containing 
the  substances  in  which  the  ratio  of  nitrogen  is  1  :  3,  or  1  : 4,  or  2 :  5  ;  the 
most  important  fraction  of  this  portion  consists  of  acids  of  the  formula 
C.H^NO,,  C„H211_3N03,  C2llHJn_4N206,  and  C„H2tt_1N03,  the 
intermediate  term  being  only  a  molecular  combination  of  the  terms 
CnH2n_3N03  and  C^H^^NOg.    The  second  portion,  which  consti- 
