40 
LIQUID  PERMANGANATE  OF  POTASH. 
by  means  of  the  apparatus  of  Mr.  Carre*,  of  which  mention  is 
made  below. 
The  same  fact  is  made  use  of  in  the  concentration  of  mineral 
waters,  a  problem  which  has  offered  itself  for  a  long  time,  but 
which  the  employment  of  heat  could  not  solve,  on  account  of  the 
gas  originally  in  solution,  which  the  heat  expelled.  Cold  works 
better.  Dr.  Ossian  Henry,  of  Paris,  has  experimented  with 
forty  different  varieties  of  water,  and  finds  that  it  is  possible  by 
congelation,  to  reduce  mineral  waters  to  one-eighth,  one-tenth, 
one-fifteenth,  or  even  one-twentieth  of  their  original  volume, 
without  producing  any  alteration  in  the  gases  contained  in 
them. 
100  litres  of  mineral  water  can  thus  be  reduced  to  5,  giving 
great  economy  in  transportation  ;  moreover,  the  ice  itself  is  also 
valuable.  But  we  do  not  believe  that  the  therapeutic  proper- 
ties of  the  extract  will  be  identical  with  those  of  the  water  in 
its  original  state,  because  of  the  changes  which  manifestly  take 
place  in  the  contained  salts,  changes  so  evident  that  Mr.  Balard 
has  been  able  to  base  upon  them  a  manufacture  of  sulphate  of 
soda,  by  exposing  to  a  temperature  sufficiently  low  the  waters 
containing  NaCl  and  MgO,  S03,  which  result  from  the  manu- 
facture of  sea.salt  by  the  evaporation  of  sea  water. 
The  publication  of  this  process  has  given  occasion  for  a  pro- 
test on  the  part  of  Mr.  Tichon,  an  apothecary  of  Aix  les  Bains 
(Savoy),  according  to  which  the  same  process  has  been  used 
since  1856,  by  him  and  a  Mr.  Melsens,  who  was  staying  at  Aix 
for  his  health.  The  mineral  water  which  he  drank  here,  and 
which  is  sulphurous,  proving  disagreeable  to  his  taste,  he  un- 
dertook to  remove  part  of  the  odor  by  submitting  it  to  a  freezing 
mixture.  In  this  way  he  was  able,  not  only  to  mask  the  disa- 
greeable odor,  but  also  to  concentrate  the  mineral  ingredients. 
Mr.  Tichon  adds  that  congelation  will  not  suit  all  mineral 
waters,  inasmuch  as  it  alters  the  organic  matter  therein  dis- 
solved.— Am.  Journ.  Science  and  Arts,  Nov.,  1863. 
LIQUID  PERMANGANATE  OF  POTASH. 
M.  Leconte  prepares  this  solution  in  the  following  manner : 
Caustic  potash,  six  drachms ;  chlorate  of  potash,  five  drachms ; 
