PREPARATION  OF  MATCHES  FREE  FROM  PHOSPHORUS.  73 
Oxide  of  iron  may  be  replaced  by  oxide  of  lead  or  of  manga- 
nese. The  above  preparation  will  not  ignite  on  sandpaper,  but 
requires  a  surface  specially  prepared  for  it,  and  the  author  em- 
ploys the  following  on  the  boxes  : 
Sulphide  of  antimony    .        .        .20  parts. 
Bichromate  of  potash   .        .        .      2  to  4  " 
Oxide  of  iron,  lead,  or  manganese  .     4  to  6  " 
Glass  powder    ....      2  " 
Strong  glue  or  gum    .         .        .      2  to  3  " 
Another  composition  is  described  by  Dr.  H.  Poltzer.*  A 
solution  of  sulphate  of  copper  is  divided  into  two  equal  parts — 
one  is  supersaturated  with  ammonia,  the  other  with  hyposulphite 
of  soda.    The  two  solutions  are  now  mixed,  and  the  mixture  is 
briskly  stirred.    A  violet-colored  powder  now  deposits,  which 
is  a  compound,  says  the  author,  of  hyposulphurous  acid  with 
oxide  and  suboxide  of  copper,  soda,  and  ammonia.    A  mixture 
of  this  salt  with  chlorate  of  potash  detonates  when  struck  with 
a-  hammer,  and  when  rubbed  in  a  mortar  ignites  and  burns  like 
gunpowder,  leaving  a  black  residue. 
The  above  salt  the  author  proposes  to  use  for  matches.  It 
is  not  soluble  in  water,  and  the  mixture  with  chlorate  of  potash 
is  not  hygroscopic.  The  mixture  may  be  made  with  moist 
chlorate  and  the  gum  solution,  and  can  be  safely  dried  at  50° 
C.  or  higher.  It  inflames  when  rubbed  on  a  rough  surface,  and 
the  temperature  developed  is  sufficiently  high  to  ignite  sulphur 
on  the  stick. 
The  only  difficulty  the  author  finds  is  in  making  the  mass  co- 
herent :  when  dried  on  the  stick  he  found  that  it  would  crack 
and  drop  off  when  rubbed.  A  manufacturer  will  probably  soon 
overcome  this  difficulty. 
The  proportions  made  use  of  were  one  part  of  the  copper  salt, 
and  two  parts  of  chlorate  mixed  in  a  sieve,  and  then  made  into 
a  mass  with  solution  of  gum,  together  with  a  little  glass  pow- 
der. This  mixture  was  applied  to  matches  dipped  in  sulphur  as 
usual. — London  Chem.  News,  Dee,  10,  1864. 
*  Polytech,  Centralblatt,  1863,  p.  1642. 
