70     OXIDIZING  ACTION  OF  FUSED  CHLORATE  OF  POTASH. 
Peroxide  of  iron  is  not  converted  into  ferrate  of  potash  ;  it  re- 
mains perfectly  unaltered,  and  only  causes  a  violent  evolution  of 
oxygen  gas ;  protoxide  of  iron  ignites  and  burns  to  peroxide. 
Fragments  of  the  size  of  a  pea  of  ordinary  roll-sulphur,  burn 
with  an  extremely  intense  white  light  to  form  sulphate  of  potash  ; 
peroxide  of  phosphorus  in  the  same  way  forms  phosphate  of 
potash. 
Phosphorus  must  only  be  employed  in  small  fragments  of  the 
size  of  a  pin's  head,  in  a  perfectly  dry  state,  and  always  with 
care  ;  the  combustion  takes  place  with  evolution  of  an  extremely 
intense  white  light. 
Pulverulent  antimony  burns  with  scattering  sparks. 
Iron-filings  burn  away  with  a  fine  light  when  the  chlorate  of 
potash  has  been  so  far  heated  that  the  evolution  of  oxygen  gas 
begins  to  be  violent ;  glowing  globules  of  sesquioxide  of  iron  are 
formed,  and  usually  pierce  through  the  bottom  of  the  test-tube, 
for  which  reason  great  caution  is  to  be  recommended. 
Metallic  arsenic  burns,  diffusing  an  intense  white  light,  and 
forming  arseniate  of  potash. 
Powder  of  bismuth  does  not  ignite,  but  is  gradually  converted 
into  oxide  of  bismuth. 
White  sugar-candy  burns  with  an  extremely  beautiful  violet 
light,  which  finally  becomes  white. 
Lead-filings  have  no  action ;  carbonate  of  lead  becomes  con- 
verted into  peroxide  of  lead. 
Platinum-black  and  fine  spongy  platinum  burn  with  a  very 
slight  scattering  of  sparks. 
Fragments  of  tin-foil  are  burnt  with  difficulty,  and  with  a 
scarcely  perceptible  scattering  of  sparks,  and  only  when  the 
evolution  of  oxygen  begins  to  grow  violent ;  it  forms  peroxide. 
Tin-dust  behaves  in  the  same  way,  as  does  silver-dust  (true  silver- 
bronze.) 
Very  fine  copper-dust  (true  copper-bronze)  burns  briskly  to 
form  oxide  ;  this  is  also  the  case  with  false  gold-bronze  (an  alloy 
of  copper  and  zinc.) 
Paris  blue  burns  with  a  strong,  beautiful  violet  light,  leav- 
ing peroxide  of  iron. 
Crystallized  gallic  acid  detonates  violently,  with  a  strong  evolu- 
tion of  light ;  hence  great  caution  is  necessary. 
