AmAP°iiir;i908*mi"}       Notes  on  Proteid  Iron  Solutions.  167 
cent,  manganese.  It  is  a  manganese  sodium  citrate,  freely  water- 
soluble. 
There  are  at  least  two  additional  soluble  manganese  citrates,  but 
no  sample  of  these  was  found  on  the  market.  (I  have  myself  pre- 
pared the  four  scale  salts  and  will  make  these  the  subject  of  a 
future  paper.) 
Which  of  the  scale  salts  of  the  market  is  to  be  used  ?  One  gives 
the  finished  product  a  manganese  content  of  about  '145  per  cent., 
the  other  about  -108  per  cent.  The  latter  yields  a  product  of  about 
the  same  manganese  content  as  the  solution  approved  by  the  Com- 
mittee on  Pharmacy  and  Chemistry  of  the  A.M. A.;  but  in  Proceed- 
ings A.Ph.A.,  51,  400,  we  are  told  that  the  former  was  intended. 
But  why  use  these  scale  salts  of  variable  composition  at  all  ?  The 
normal  manganese  citrate  is  a  definite  chemical  compound  contain- 
ing 23  per  cent.  Mn.  It  is  freely  soluble  in  ammonium  hydroxide 
or  sodium  citrate  solution.  It  costs  about  one-half  as  much  (per 
gramme  manganese)  as  the  double  salts. 
In  view  of  the  above  facts,  it  seems  that  a  satisfactory  preparation 
according  to  the  present  N.  F.  formula  is  impossible,  although  with 
a  good  sample  of  peptonized  iron  it  could  yield  a  passable  one.  A 
sample  of  peptonized  iron  which  promises  to  keep  well  (containing 
about  15  per  cent.  Fe)  has  been  prepared  by  the  writer,  but  the 
formula  is  withheld  until  it  can  be  proven  to  keep  satisfactorily. 
A  liquor  ferri  peptonati  cum  mangano  may  be  prepared,  however, 
by  slightly  modifying  the  formula  of  liquor  ferri  peptonati.  All 
that  is  necessary  is  to  increase  the  amount  of  sodium  citrate  to  25 
grammes,  and  dissolve  in  the  solution  of  this  salt  in  water  4*4 
grammes  normal  manganese  citrate  before  adding  it  to  the  pepton- 
ized iron. 
The  finished  product  leaves  little  further  to  be  desired  and  is 
identical  with  liquor  ferri  peptonati,  except  that  it  contains  in  addition 
•I  per  cent,  manganese. 
Attempts  to  supply  the  manganese  by  means  of  manganese- 
chloride  resulted  in  the  product  having  an  objectionable  salty  taste. 
The  iron  and  manganese  cannot  be  precipitated  together  as  pep- 
tonized compounds,  because  in  the  presence  of  ammonium  chloride 
the  peptonized  iron  requires  too  large  an  excess  of  alkali  for  com- 
plete precipitation,  while  in  the  absence  of  the  ammonium  salt  (#.  e.f 
from  iron  oxychloride  solution)  the  peptonized  iron  precipitates  in 
