AmNo°Ci^arm' }  Serum-  and  Egg- Albumin.  5 1 5 
SERUM-  AND  EGG-ALBUMIN  AND  THEIR  COMPOUNDS. 
BY  A.  HEYNSIUS. 
After  recapitulating  the  results  of  his  former  paper  (Jour.  Chem. 
Soc.  [2],  xiii,  469),  the  author  brings  forward  objections  to  Schmidt's 
view,  that  albumin  is  a  substance  of  itself  soluble  in  water  (see  this 
Journal  [2],  xiv,  87 — 89).  Schmidt  obtained  by  dialysis  a  neutral  liquid, 
which  did  not  coagulate  on  heating,  and  contained  no  soluble  ash-con- 
stituents.   The  author's  objections  to  Schmidt's  conclusion  are  : 
1.  A  neutral  reaction  does  not  necessarily  mean  entire  absence  of 
alkali,  inasmuch  as  alkali  can  combine  with  egg-white  without  causing 
the  reaction  to  become  alkaline.  This  is  proved  by  experiment.  After 
long-continued  dialysing  a  liquid  was  obtained,  which  became  turbid 
at  lower  temperatures  than  that  obtained  after  a  shorter  process  of 
dialysing  ;  because  in  the  former  case  the  alkali  was  more  completely 
removed. 
2.  The  failure  of  Schmidt  to  obtain  any  soluble  salts  from  the  liquid, 
which  he  regarded  as  a  solution  of  pure  albumin,  is  ascribed  to  the 
small  quantity  of  material  employed.  It  is  shown  by  experiment  that 
an  amount  of  alkali,  which  is  so  small  as  to  be  unrecognized  in  the  ash 
of  such  quantities  of  liquid  as  Schmidt  employed,  is  sufficient  to  pre- 
vent coagulation  of  albumin  (blood-serum  and  egg-white)  on  heating. 
A  minute  trace  of  acid  also  prevents  coagulation. 
^-ths  cc.  of  ro0(j  normal  alkali  (=0*0000124  grm.)  caused 
dialysed  blood-serum  to  remain  clear  on  boiling.  2  cc.  of  the  same 
solution  (=0*000062  grm.  alkali)  prevented  coagulation  of  dialysed 
egg-white.  Totns  and  Totns  °f  cc*  °f  lio  normal  acid  solution  respec- 
tively prevented  coagulation  in  blood-serum  and  in  egg-white. 
It  is  further  urged  that  the  small  quantity  of  alkali  present  in 
dialysed  albumin  will  most  probably  be  found  in  the  insoluble  ash,  inas- 
much as  it  is  known  that  alkali — especially  soda — when  heated  with 
phosphates  of  the  earths,  gives  insoluble  double  salts. 
The  author  concludes  that,  after  the  most  careful  dialysing, 
there  is  obtained : — 1.  A  compound  of  albumin  with  calcium  (and 
magnesium)  phosphate,  which  is  soluble  in  water,  and  from  which 
albumin  is  precipitated  on  boiling.  2.  That  albumin  free  from  salts 
cannot  be  obtained  by  dialysis,  and  that  we  are  not  therefore  justified 
in  saying  that  albumin  is  of  itself  soluble  in  water.  3.  That  with 
this  compound  there  is  associated  (in  the  case  of  blood-serum,  at 
