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DETECTION  OP  IODINE  IN  MINERAL  SPRINGS. 
and  still  more  tenacious.  According  to  Wertheim  its  tenacity  is 
to  that  of  iron  as  115  to  60,  or  nearly  double.  The  most  re- 
fractory body  which  the  author  fused  was  silica,  which,  however, 
in  quantities  of  30  grammes  was  not  perfectly  liquified.  The 
author  considers  the  fusion  of  this  body  as  the  limit  beyond 
which  processes  do  not  go. — American  Journal  of  Science  and 
Arts,  from  Ann.  de  Qhimie  et  de  Physique,  xlvi.  182,  Febru- 
ary, 1856. 
ON  THE  DETECTION  OF  IODINE  IN  MINERAL  SPRINGS. 
By  J.  Liebig. 
When  a  very  small  quantity  of  an  alkaline  iodate,  followed  by 
sulphuric  or  muriatic  acid,  is  added  to  a  fluid  which  contains  so 
small  a  quantity  of  metallic  iodides  that  no  distinct  blue  colora- 
tion can  be  obtained  by  starch  and  nitric  acid,  a  far  stronger  re- 
action is  obtained  ;  hydriodic  acid  and  iodic  acid  being  separated, 
which  become  mutually  converted  into  water  and  iodine,  so  that 
the  amount  of  iodine  set  free  is  increased  by  the  iodic  acid  added. 
Neither  iodic  acid  nor  iodide  of  potassium  mixed  with  muriatic 
acid,  colors  starch. 
When  the  mother-liquor  of  a  mineral  spring  was  mixed  with 
starch-paste  and  muriatic  acid,  with  the  intention  of  adding  iodic 
acid  to  it  afterwards,  the  author  observed  that  it  produced  as 
fine  a  blue  color  as  can  be  produced  by  any  of  the  known  methods, 
by  means  of  chlorine-water,  hyponitrous  acid,  &c.  The  water 
of  the  Adelheid  spring,  the  mother-liquor  of  the  Reichenhall 
bath,  and  in  fact  all  the  waters  containing  iodine  which  he  ex- 
amined, behaved  in  exactly  the  same  manner  ;  with  starch-paste, 
and  the  addition  of  pure  muriatic  acid  and  free  from  chlorine  and 
iron,  they  gave  as  distinct  a  reaction  as  can  be  obtained  with  other 
very  delicate  reagents.  The  same  muriatic  acid  gives  not  the 
least  color  with  iodide  of  potassium  and  starch-paste,  so  that  some 
body  must  exist  in  these  waters  which  sets  free  the  iodine  of  the 
iodide,  or  the  liberated  hydriodic  acid,  on  the  addition  of  a 
mineral  acid.  It  seems  probable  that  this  may  be  due  to  the 
presence  of  nitrates,  which  the  author  found  in  these  waters,  and 
frequently  in  large  proportion ;  but  he  does  not  feel  certain  that 
these  are  the  cause  of  the  reaction,  as  by  mixing  such  salts  with 
