250  Decomposition  of  Potassic  Chlorate.  {Am,May%889arm' 
Sodium  salicylate  solutions  after  a  short  time  develop  a  red  color, 
rendering  them  unfit  for  use.  This  decomposition  takes  place  especi- 
ally in  alkaline  solution  ;  a  fresh  solution  of  sodium  salicylate  has  a 
slightly  acid  reaction  ;  but  this  reaction,  especially  in  concentrated  so- 
lutions, is  destroyed,  and  instead  an  alkaline  reaction  appears,  depend- 
ent upon  which  is  the  depth  of  color  of  the  solution.  S.  Deniant 
gives  the  following  formula  for  a  20  per  cent,  solution,  which  remains 
unchanged  for  months  ;  its  stability  is  due  to  a  slight  excess  of  sali- 
cylic acid,  which  in  no  way  interferes  with  its  action  :  400  parts  dis- 
tilled water  are  heated  to  the  boiling  point,  allowed  to  cool  to  30°  C, 
100  parts  salicylic  acid  added,  and  then  60  parts  bicarbonate  of  so- 
dium introduced,  in  small  portions,  with  constant  stirring,  the  solu- 
tion is  filtered  through  absorbent  cotton  and  diluted  with  sufficient 
distilled  water  to  make  600  parts. —  Oesterr.  Ztsch.  f  Pharm.,  1889, 
171. 
NOTE  ON  THE  DECOMPOSITION  OF  POTASSIC  CHLO- 
RATE BY  HEAT  IN  THE  PRESENCE  OF  MANGANIC 
PEROXIDE.1 
Having  observed  the  alteration  in  appearance  that  peroxide  of  man- 
ganese undergoes  when  heated  with  potassic  chlorate,  the  author  has 
made  a  number  of  experiments,  using  different  kinds  of  oxide  of  man- 
ganese, determining  the  loss  of  weight  that  the  mixture  suffers  when 
heated,  and  also  the  quantity  of  chlorine  simultaneously  generated. 
The  heating  was  generally  effected  by  the  vapor  of  boiling  mercury,  at 
which  temperature  the  potassic  chlorate  is  not  changed.  The  more 
finely  divided  the  peroxide,  the  more  rapid  is  the  action  and  the  more 
chlorine  is  evolved.  When  the  evolution  of  chlorine  is  prevented  by 
the  addition  of  a  small  quantity  of  sodic  or  potassic  carbonate,  the 
decomposition  of  the  chlorate  proceeds  very  slowly,  unless  the  temper- 
ature be  raised  much  above  that  of  boiling  mercury.  When  potassic 
chlorate  is  fused  with  a  minute  quantity  of  peroxide  of  manganese,  the 
residue  is  found  to  be  pink  on  cooling,  indicating  the  presence  of  a 
permanganate ;  and  inasmuch  as  potassic  permanganate  is  decomposed 
at  a  temperature  of  275°,  it  is  not  improbable  that  the  permanganate 
is  decomposed  by  the  heat  as  rapidly  as  it  is  produced  into  potassic 
1  Abstract  of  a  paper  read  before  the  Chemical  Society;  reprinted  from  Chem- 
ical News,  March  1,  p.  104. 
