2j6  Preparing  a  Hematin  Product.  {Am/U°uer;i902arm' 
The  only  reason  why  preparations  of  this  kind  have  not  become 
popular  is  to  be  found  in  their  prohibitive  price,  due  to  the  expense 
and  to  the  small  yield  of  the  present  processes  of  manufacture.  The 
only  products  which  come  within  the  range  of  practicability  are  re- 
duction-derivatives :  hemogallol,  prepared  by  the  action  of  pyrogal- 
lol  ;  and  hemol,  prepared  by  the  action  of  zinc.  These  are  rather 
further  removed  from  hemoglobin  than  is  desirable  ;  there  is  always 
some  danger  of  contamination  with  the  chemicals  used  in  their 
manufacture  ;  the  processes  are  not  such  as  can  be  readily  employed 
in  the  average  pharmacy ;  and  the  cost  of  the  preparations  is  still 
very  high,  especially  when  the  effective  dose  is  considered. 
II.  PRELIMINARY  EXPERIMENTS. 
The  problem  which  I  set  before  myself  was,  therefore,  to  devise 
a  process  yielding  a  physiological  hemoglobin  derivative,  by  a 
method  requiring  only  simple  manipulations  and  apparatus,  and 
which  should  still  give  a  permanent  product  sufficiently  pure  for 
medicinal  use,  at  a  minimum  cost.  It  is  known  that  hemoglobin, 
taken  by  the  mouth,  is  changed  to  hematin  before  absorption.  This 
derivative  was,  therefore,  the  one  which  I  aimed  to  isolate. 
Hemoglobin  and  its  derivatives  are  proteids,  and  agree  closely 
with  the  other  serum  proteids  in  their  physical  and  chemical  char- 
acters. The  precipitability  and  solubility  are  nearly  the  same,  and 
hence  arise  the  difficulties  in  isolating  a  pure  hemoglobin  product. 
A  difference  exists  in  the  behavior  to  acidified  alcohol  and  ether- 
Hematin  is  somewhat  soluble  in  these  media,  whereas  the  other 
serum  proteids  are  insoluble.  This  is  the  basis  of  the  processes  so 
far  employed  for  the  isolation  of  these  products,  and  my  first  experi- 
ments were  made  along  this  line.  On  account  of  the  very  limited 
solubility  of  the  hematin,  the  yield  was  so  small,  considering  the 
large  loss  of  the  expensive  solvents  and  the  tediousness  of  the  pro- 
cess, that  the  cost  of  the  product  would  render  it  useless. 
After  some  further  experimentation  it  occurred  to  me  that  an  effi- 
cient separation  might  be  secured  very  cheaply  by  peptic  or  other 
digestion.  Peptic  digestion  (in  an  acid  medium)  converts  the  serum 
proteids  first  into  acid-albumins,  then  into  albumoses,  whilst  hemo- 
globin is  changed  to  acid-hematin.  When  the  liquid  is  rendered 
neutral  the  acid-albumin  and  acid-hematin  are  precipitated,  whereas 
the  albumose  remains  in  solution.    It  would  therefore  only  be  neces- 
