LIQUOR  FBRRI  IODLDI. 
23 
bottle  afterward  be  but  partly  filled,  and  kept  in  a  dark  place. 
The  same  result  is  also  obtained  by  the  addition  of  a  few  drops 
of  tincture  of  iodine  to  the  ordinary  liquor,  and  exposure  to  the 
heat  and  sun  as  above.  In  proof  of  this,  I  forward  to  you,  Mr. 
Editor,  two  small  bottles,  which  have  served  me  in  my  experi- 
ments, the  one  labelled  made  October  3d,  1857,  the  other  June 
3d,  1858  ;  both  were  exposed  to  the  rays  of  the  sun  till  January 
4th,  1859,  when  they  were  taken  into  the  cellar  and  left  there 
ever  since. 
3d.  That  iodine  forms  with  sugar  a  chemical  combination,  as 
it  is  explained  below. 
4th.  That  the  liquor  of  iodide  of  iron  is  improved,  and  ren- 
dered more  perfect  by  exposure  to  the  rays  of  the  sun. 
I  will  here  mention  a  formula  which  I  have  used  for  some  time 
with  satisfaction ;  it  consists  in  introducing  4  oz.  crushed  sugar 
into  a  Florence  flask  along  with  the  water,  iodine  and  iron  ;  when 
the  salt  of  iron  is  formed,  which  is  known,  as  usual,  by  the  light 
green  color  of  the  liquor,  it  is  filtered  over  the  remaining  8  oz. 
of  sugar,  boiled  and  strained  as  any  other  syrup.  This  process 
of  adding  a  part  of  the  sugar  to  the  first  operation,  has  the  ad- 
vantage of  furnishing  a  sweetened  green  solution,  which  can  be 
filtered  with  as  much  ease  as  simple  water,  without  fear  of  aiiy 
decomposition. 
However  good  the  above  formula  may  be,  I  have  abandoned 
it  for  the  following  : 
Liquor  Ferri  Iodidi  U.  S. 
R.  Iodini  sublimat.  Sij. 
Pulv.  Ferri  puri  ^v. 
Sacchari  Albi  gxij. 
Aquae  destillatae  q.  s.  vel.  %xlv. 
Ut  fiat  solutio  secundum  artem. 
The  Jodine  is  weighed  separately  in  a  wide  mouth  bottle,  per- 
fectly dry  ;  all  of  the  iron  and  about  6  oz.  of  water,  more  or  less, 
makes  no  difference,  is  introduced  into  an  ordinary  bottle,  and 
the  iodine  added  in  small  quantities  (one  to  two  drachms),  adding 
a  new  portion  only  when  the  previous  one  is  combined  to  the 
iron.  As  soon  as  a  portion  of  iodine  is  thrown  into  the  iron 
water,  the  operator  is  to  shake  the  bottle  continuously  until  the 
