VARIETIES. 
363 
genus  of  which  the  labors  of  the  great  Cuvier  first  disclosed  the  history, 
under  the  name  of  Palceotherium,  in  publishing  his  description  of  the  fossil 
bones  exhumed  from  the  gypsum  quarries  of  Montmartre,  near  Paris,  but 
are  distinct  in  species  ;  and  one,  at  least,  of  this  genus,  discovered  in  the 
Bad  Lands  [Palocotlierium  Proutii,^  must  have  attained  a  much  larger  size 
than  any  which  the  Paris  basin  afforded.  In  a  green,  argillo-calcareous, 
indurated  stratum,  situated  within  ten  feet  of  the  base  of  the  section,  a  jaw 
of  this  species  was  found,  measuring,  as  it  lay  in  its  matrix,  five  feet  along 
the  range  of  the  teeth,  but  in  such  a  friable  condition,  that  only  a  portion 
of  it  could  be  dislodged ;  and  this,  notwithstanding  all  the  precautions  used 
in  packing  and  transportation,  fell  to  pieces  before  reaching  Indiana. — 
American  Journ.  of  Science  and  Arts.,  March,  1853. 
Fusion  and  volatilization  of  Platinum  and  Silica. — Berzelius  in  his  Traite 
de  Cbemie  (German  edition)  reports  that  he  had  seen  a  mass  of  semifused 
platinum  which  M.  Sefstrom  had  obtained  by  heating  in  an  ordinary  fur- 
nace filings  of  platinum  mixed  with  charcoal  placed  in  a  crucible.  This  fact, 
which  had  been  overlooked,  has  been  carefully  studied  and  submitted  to 
examination  on  a  large  scale  by  M.  Deville,  so  that  now  the  fusion  of  pla- 
tinum in  a  coal  fire  is  no  more  a  difficulty,  neither  the  volatilization  of  this 
metal. 
In  order  to  verify  a  fact  in  analytical  chemistry  concerning  the  silicates, 
M.  Henri  St.  Claire  Deville  put  a  platinum  crucible,  closed  with  its  cover, 
in  a  Hessian  crucible,  and  placed  it  in  a  small  laboratory  furnace.  The 
combustible  consisted  accidentally  of  furnace  cinders  ("  escarbilles  ")  and 
the  whole  was  subjected  to  the  action  of  the  bellows  of  a  forge.  On  return- 
ing after  some  time  to  examine  the  state  of  the  silicate,  he  saw  with  sur- 
prise that  the  platinum  crucible,  as  well  as  the  Hessian,  was  reduced  to  a 
paste,  perfectly  fused. 
On  reporting  the  facts  to  the  Academy,  M.  Deville  presented  a  platinum 
crucible,  which  he  had  caused  to  melt  in  lime  ;  he  had  also  a  cover  of  pla- 
tinum, and  also  a  specimen  of  pure  silver  fused  in  graphite. 
As  sandstone  is  perfectly  fusible  at  these  temperatures,  M.  Deville  sub- 
stitutes for  it  some  compact  lime  containing  a  little  silica,  which  he  had 
carved  into  a  crucible  ;  the  air  reached  the  furnace  through  a  plate  of  iron 
pierced  with  holes  arranged  circularly  to  a  distance  of  5  centimeters  around 
the  center. 
I  have  seen  the  apparatus,  and  observed  the  simple  and  easy  method  of 
using  it ;  the  humble  appearance  of  this  small  furnace  stands  out  the  more 
remarkably  in  the  magnificeut  laboratory  of  the  Ecole  JSTormale,  where  M. 
Deville  carries  on  his  labors.  This  chemist  has  also  succeeded  in  volatili- 
zing silica,  which  had  already  been  previously  done  by  M.  Gaubin,  with  a 
gas  blowpipe  of  his  invention,  fed  by  oxygen. 
It  is  essential  for  success  that  the  combustible  should  be  of  the  proper 
kind,  and  finely  divided.    The  best  is  made  of  the  residue  of  the  combus_ 
