ol8   HYPOPHOSPHITE  OF  IRON  AND  SYRUP  OF  HYPOPHOSPHITES. 
pound  syrup  of  hypophosphites  with  hypophosphite  of  peroxide 
of  iron,  prepared  by  precipitation  from  a  solution  of  persulphate 
of  iron  with  hypophosphite  of  soda;  which,  if  the  manipulation 
is  not  carefully  conducted,  results  in  the  loss  of  nearly  all  the 
iron  salt  and  in  the  almost  total  absence  of  iron  from  the  syrup 
when  completed. 
In  the  course  of  my  experiments  on  this  subject,  I  have  ob- 
served that  a  persalt  of  iron  in  the  presence  of  sugar,  in  solu- 
tion, undergoes  a  change  and  is  gradually  converted  into  a  pro- 
tosalt.  This  remarkable  fact  may  be  proved  by  mixing  a  solu- 
tion of  persulphate  of  iron  with  about  an  equal  bulk  of  simple 
syrup.  At  the  end  of  a  few  hours  the  change  may  be  observed 
by  testing  the  mixture,  and  in  a  much  more  satisfactory  manner 
in  the  course  of  two  or  three  days,  when  the  presence  of  the 
protosalt  will  be  decidedly  shown  by  adding  a  solution  of  ferri- 
oyanide  of  potassium  to  a  portion  of  the  mixture  contained  in  a 
test  tube. 
I  do  not  attempt  an  explanation  of  the  exact  nature  of  the 
change  which  takes  place  in  this  deoxidizing  process,  but  it  is 
evident  that  sugar  deprives  the  peroxide  of  iron  of  one  third  of 
its  oxygen  to  convert  it  into  the  protoxide. 
The  fact,  that  saccharine  matter  will  effectually  protect  a 
Protosalt  of  iron  from  the  action  of  oxygen  and  conversion  into 
a  persalt,  has  been  known  for  many  years,  and  its  discovery  is 
attributed  to  Dr.  Becker,  a  German  physician.  The  idea  was 
first  carried  out  by  Dr.  Klauer,  who  first  made  the  saccharine 
carbonate  of  iron ;  but  I  cannot  find  any  reason  assigned  for  the 
fact  that  this  protective  influence  is  exercised  by  sugar,  nor  any 
attempt  to  explain  the  mode  of  its  action. 
In  Gmelin's  Hand-book  of  Chemistry,  vol.  5,  page  201,  the 
following  paragraph  occurs  :  "  Ferric  salts  are  reduced  to  the 
state  of  ferrous  or  ferroso-ferric  salts  by  many  vegetable  sub- 
stances ;  fresh  grass,  the  green  branches  of  trees  and  shrubs, 
hay,  wood-shavings,  saw-dust,  peat  and  coal  effect  the  reduction 
at  ordinary  temperatures;  sugar,  starch,  gum,  alcohol,  turpen- 
tine, and  shreds  of  paper  at  a  boiling  heat.  (Stenhouse,  Ann. 
Pharm.  51,  284.)" 
This  throws  some  light  on  the  subject,  but  it  seems  to  have 
