Bengal  Lights.  Beddes  the  combus-
tible and  coloring  oomiiom  iits,  the  fire-
works known  under  this  name  contain
substances  which,  by  yieldiji<;  oxygen,
aid  combustion,  l^e  pnnci|)al  ingre-
dients used  for  this  purpose  are  char-
coal, lampblack,  sulfur,  stearine,  lin-
Oiriridges  for  Extinguishing  Fire.  \  seed  oil,  colophony,  sugar,  etc  F<»r
Make  the  sheUs  of  parchment  paper  or  coloring  the  ui^ts  the  following  sub-
sheet  lead,  and  fill  tnem  with  4  parts  of  stances  are  made  use  of:  Sulphide  of
a  salt  obtained  by  mixing  313  parts  of  '  antimony,  arsenical  sulphides,  nitrate
sulphate  of  alumina  and  142  parts  of  '  of  barium,  nitrate  of  strontium,  sul-
sodium  sulphate  with  432  of  water ;  and  phate  of  potassium,  carbonate  of  sodium,
1  part  of  sodium  sulphide,  separated .  cnpric  oxide,  borarac  acid,  chlorate  of


FIREWORKS.
125


potassium,  saltpetre,  etc.  In  preparing
colored  lights  the  greatest  attention
should  be  paid  to  the  absolute  purity
of  the  ingredients  used,  and  that  they
are  powdered  as  finely  as  possible  and
very  intimately  mixed  witn  a  spatula
after  pulverization.  Every  mixture
containing  chlorate  of  potassium  must
be  treated  and  handled  with  the  utmost
care  and  caution,  as  such  mixtures  are
liable  to  spontaneous  ignition  and  even
to  explosion.  For  preparing  a  very
fine  powder  of  it,  it  is  best  to  allow  a
supersaturated  hot  solution  of  chlorate
of  potassium  to  become  cold,  with  con-
stant stirring,  when  the  salt  will  be
separated  in  the  form  of  a  verv  fine
crystallized  flour,  which  should  be
dried  without  exposing  it  to  direct  heat.
