Researches  on  Albumin. 
{'  Am  Jour.  Phaim. 
Sept.,  1879. 
tutes  four-fifths  of  the  residue,  may  be  represented  by  the  formula 
x(CnH2nN204),  with  a  value  for  n  a  little  less  than  9.  According  as 
the  limit  of  hydration  is  attained  the  products  formed  belonging  to 
the  type  CmH2mN204  (where  m  is  a  multiple  of  n)  are  progressively 
resolved  into  simple  bodies  belonging  to  the  same  apparent  type;  these 
again  resolved  into  bodies  of  the  type  CnH2llN204,  which  in  their  turn? 
are  resolved  into  leucins,  CnH2nilN02,  and  leuceins,  CnH2n_1N02. 
This  interpretation  is  not  affected  by  the  presence  of  more  highly 
oxygenated  acids  in  the  fixed  residue,  since  they  may  be  considered  as 
derived  from  any  of  these  bodies  by  substitution  of  O  for  H2. 
To  the  memoir  is  added  an  appendix,  in  which  are  given  the  results 
of  some  analyses  made  of  fixed  residues  obtained  from  different  sources* 
Albumin  purified  by  Wurtz's  method  was  substituted  for  crude  albumin  > 
the  baryta  was  precipitated  in  one  instance  by  carbonic  anhydride,  in 
another  by  carbonic  anhydride  and  sulphuric  acid,  and  in  a  third  by 
carbonic  anhydride,  ammonia  and  ammonium  carbonate,  but  no  import- 
ant differences  were  observable  in  the  products  of  decomposition.  It 
was  also  found  to  be  a  matter  of  indifference  whether  the  hydration  of 
the  albumin  was  begun  by  the  action  of  other  agents  less  energetic 
than  baryta,  such  as  dilute  sulphuric  acid  ;  on  completing  the  action  by 
the  intervention  of  baryta  as  usual,  the  same  result  was  obtained  as  in 
the  previous  instances.  A  fixed  residue  obtained  by  the  action  of 
baryta  was  subsequently  boiled  for  24  hours  with  a  20  per  cent,  sul- 
phuric acid,  but  its  composition  was  not  found  to  be  sensibly  affected. 
In  a  final  operation,  conducted  with  the  usual  reagents,  the  action 
of  baryta  upon  albumin  was  carried  to  its  extreme  limit.  The  fixed 
residue  was  carefully  examined  to  see  whether  any  substance  was  pro- 
duced under  such  condition,  which  had  not  been  found,  or  had  been; 
overlooked  in  previous  experiments  ;  nothing,  however,  was  met  with 
but  the  usual  mixture  of  leucins  and  leuceins. 
The  molecular  weight  of  the  various  glucoproteins  still  remains  to 
be  determined. — Ann.  Chim.  Phys.^  [5],  16,  289-419,  from  Jour.  Chem. 
Soc,  July  1879,  p.  542. 
A 
