Am.  Jour.  Pharm.  1 
Feb.,  1881.  / 
Potassium  Permanganate. 
69 
tinder  polarization.  It  is  moderately  soluble  in  alcohol  and  very  spar- 
ingly so  in  ether  and  benzin,  but  dissolves  readily  in  boiling  water.  It 
^ives  a  faint  red  color  with  ferrous  salts.  It  gives  up  its  water  of 
crystallization  between  100  and  120°  without  decomposition,  but 
becomes  blackened  at  190°,  and  melts  at  244  to  250°.  The  aqueous 
:soliition  gives  an  amorphous  precipitate  with  barium  acetate ;  with  cal- 
cium acetate  a  warty  crystalline  mass  of  needles ;  with  silver  nitrate  an 
amorphous  precipitate,  which  becomes  crystalline  after  a  time,  and  is 
not  much  altered  by  exposure  to  light ;  with  copper  acetate  a  bright 
blue  amorphous  preci])itate ;  with  lead  acetate  (and  also  the  basic  ace- 
tate) white  amorphous  precipitates.  No  red  fumes  are  evolved  wh^n 
the  acid  is  boiled  with  concentrated  nitric  acid.  It  is  readily  acted  on 
by  permanganate  in  acid,  but  not  in  alkaline  solutions.  It  consists  in 
the  anhydrous  state  of  CgH^NOg,  and  is  tribasic.  It  crystallizes  from 
aqueous  solutions  with  mol.  of  water.  The  neutral  potassium  salt, 
CgH2K3NOg-j-3H20,  forms  brilliant  i)lates,  which  exhibit  a  fine  play  of 
color  in  polarized  light.  The  neutral  barium  salt,  when  prepared  by 
addition  of  barium  acetate  to  a  solution  neutralized  with  ammonia, 
contains  (if  precipitated  in  the  cold)  8  molecules  of  water,  and  loses 
7H2O  at  100°,  and  all  its  water  at  280  to  300°.  If  the  barium  acetate 
is  added  to  an  acid  solution  another  salt  containing,  when  dried  in  air, 
only  6H2O  is  obtained,  in  addition  to  the  one  just  described.  The 
calcium  salt  contains  THoO.  The  normal  silver  salt,  C8H2Ag3]SrOg-|- 
2H2O,  consists  of  an  amorphous  precipitate,  which  loses  part  of  its 
water  over  sulphuric  acid,  and  is  not  much  altered  by  exposure  to 
light.  It  is  obtained  by  adding  silver  nitrate  to  a  solution  of  the  acid 
neutralized  by  ammonia.  If  the  aqueous  solution  of  the  acid  is  mixed 
with  silver  nitrate  a  precipitate  is  thrown  down,  which  is  at  first 
amorphous,  afterwards  crystalline,  and  which  consists  of  CgHgAgjNOg 
+  H2O.  Another  silver  salt,  C^H^AgNOgH-CgH^NOg,  crystallizing 
with  2JH2O,  may  be  obtained  by  dissolving  the  neutral  silver  salt  in 
warm  dilute  nitric  acid  and  concentrating  the  solution. 
Cincliomeronic  acid  may  be  obtained  by  heating  tricarbopyridinic 
acid  to  180  to  190°,  when  decomposition  takes  place,  in  accordance  with 
the  equation,  03115^05=05.115X04  +  000.  This  acid  is  identical  with 
the  one  Weidel  and  Schmidt  ("  Annalen,"  clxxiii,  96)  obtained  by  direct 
oxidation  of  quiiiia,  cinchonia  and  cinchonidia.  It  is  sparingly 
soluble  in  ordinarv  solvents.  It  p^ives  no  color  when  mixed  with  fer- 
rous  sulj)hate.  It  contains  no  water  of  crystallization,  and  melts  at  250° 
