PROCESS  FOR  A   VERY  SOLID  CEMENT. 
165 
PROCESS  FOR  THE  FORMATION  OF  A  VERY  SOLID  CEMENT  BY 
THE  ACTION  OF  A  CHLORIDE  UPON  OXIDE  OF  ZINC. 
By  M.  Sorel. 
This  cement  is  a  basic  oxychloride  of  zinc.  It  is  obtained  by 
suspending  oxide  of  zinc  in  the  liquid  chloride  of  the  same  metal, 
or  in  another  chloride  isomorphous  with  chloride  of  zinc,  as  in 
protochloride  of  iron,  manganese,  nickel,  cobalt,  &c.  These 
chlorides  may  be  replaced  by  muriatic  acid. 
The  cement  will  be  harder  in  proportion  as  the  chloride  is 
more  concentrated  and  the  oxide  of  zinc  heavier.  The  washed 
residues  of  the  manufacture  of  zinc-white,  or  common  zinc-white 
calcined  at  a  red  heat,  may  be  employed ;  the  chloride  of  zinc 
should  mark  from  50°  to  60°  of  Beaum^'s  areometer.  To  cause 
the  cement  to  set  more  slowly,  about  3  per  cent,  of  borax  or 
muriate  of  ammonia  may  be  dissolved  in  the  chloride,  or  the 
oxide  may  be  suspended  in  water  containing  a  little  borax,  and 
afterwards  calcined. 
The  cement  thus  obtained  may  be  poured  into  moulds  like 
plaster  ;  it  is  as  hard  as  marble ;  cold,  moisture,  and  even  boil- 
ing water,  have  no  effect  upon  it ;  it  resists  a  heat  of  572°  F. 
without  disaggregation,  and  the  most  energetic  acids  attack  it 
very  slowly.  It  is  not  dear,  but  its  cost  might  be  considerably 
reduced  by  mixing  metallic,  siliceous,  or  calcareous  substances 
with  the  oxide  of  zinc,  such  as  iron  or  brass  filings,  iron  pyrites, 
blende,  emery,  granite,  marble,  and  any  of  the  hard  limestones. 
Soft  materials,  such  as  chalk  and  the  ochres,  would  not  do.  It 
will  readily  receive  the  brightest  and  most  various  colors,  so  as 
to  be  applicable  to  the  formation  of  mosaics,  and  other  works  of 
great  hardness  and  beauty ;  some  mosaics  made  of  it  are  already 
placed  in  the  church  of  St.  Etienne-du-Mont  in  Paris.  It  may 
also  be  employed  in  forming  moulded  objects,  such  as  statuettes, 
medallions,  bas-reliefs,  &c.  It  answers  admirably  for  a  cement, 
and  has  been  employed  for  several  years  by  some  of  the  Parisian 
dentists  in  stopping  decayed  teeth. 
It  may  be  used  instead  of  oil  in  painting  buildings.  For  this 
purpose,  pure  or  colored  oxide  of  zinc  is  suspended  in  water  and 
a  little  size  ;  this  is  applied  in  the  same  way  as  the  ordinary  size- 
colors,  and  when  as  many  layers  as  are  desired  have  been  laid 
