416 
NEW  EXPLOSIVE  SALT  OF  MERCURY. 
EXPLOSIVE  PROPERTIES  OF  OXALATE  OF  PEROXIDE  OF 
MERCURY. 
By  Peter  Hart. 
Having  two  days  ago  prepared  a  small  quantity  of  oxalate  of 
mercury,  I  allowed  it  to  remain  on  the  sand-bath  drying  until 
this  morning,  when  it  exploded  with  great  violence,  breaking 
the  basin  and  dispersing  the  fragments  so  effectually,  that  not 
more  than  three  or  four  pieces  have  been  found,  and  these  do 
not  exceed  in  size  half  a  finger  nail. 
I  was  absent  at  the  time  of  the  occurrence,  but  have  had  the 
relation  of  the  circumstance  from  my  father,  who,  in  fact  was 
reaching  out  his  hand  to  remove  the  basin  at  the  moment  the 
explosion  occurred,  having  perceived  signs  of  decomposition 
going  forward,  puffs  of  gas  coupled  with  sharp  crackings  hav- 
ing for  some  seconds  issued  from  it.  Several  of  the  fragments 
struck  him  in  the  face,  but  fortunately  did  him  no  serious  injury. 
When  I  arrived  I  found  some  half-dozen  panes  of  glass  situ- 
ated about  twenty  feet  distant  from  the  basin,  broken  by  flying 
fragments,  one  piece  of  apparatus  was  broken,  evidently  by  the 
concussion,  and  the  whole  of  the  tables,  even  at  the  farthest 
point  of  the  laboratory,  were  covered  with  sand  projected  from 
the  bath. 
I  send  you  this  account  because  it  appears  to  me  that  this 
salt  (oxalate  of  the  peroxide  of  mercury)  appears  to  be  more  ex- 
plosive than  the  books  would  lead  us  to  imagine.  Gmelin  says 
that  it  decomposes  with  a  hissing  noise.  According  to  this  author 
the  mercurous  oxalate  appears  to  be  more  explosive  than  the  mer- 
curic; for  speaking  of  the  former  salt,  he  says  :  «  When  sudden- 
ly heated  in  a  glass  tube  it  detonates."  It  is  possible  that  a 
portion  of  the  salt, I  prepared  (which  was  not  more  in  quantity 
than  from  1  to  2  ounces)  might  have  been  reduced  to  mercurous 
oxalate,  but  whether  that  was  the  case  or  not,  it  certainly  de- 
composed with  more  than  a  hissing  noise  Druggists'  Circular, 
