RELATION  OF  HYDROGEN  TO  PALLADIUM. 
181 
with  copper  as  follows,  viz  :  Pure  copper  100,  palladium  8-10, 
alloy  of  80  copper  +  20  nickel  6*63,  palladium  and  hydrogen 
5"99.  This  is  in  accordance  with  the  usual  decreased  conducting 
power  of  alloys,  and  is  in  favor  of  the  metallic  character  of  hy- 
drogenium. 
4.  3Iagnetism. — Faraday  determined  palladium  to  be  "feebly 
but  truly  magnetic."  Various  careful  and  ingenious  experiments 
were  made  with  the  alloyed  wire,  the  results  of  which  cause  Prof. 
Graham  to  believe  that  hydrogenium  is  magnetic,  a  property 
which  is  confined  to  metals  and  their  compounds,  and  is  so  much 
more  magnetic  than  palladium  that  he  inclines  to  range  it  in  the 
strictly  magnetic  group  with  iron,  nickel,  cobalt,  chromium  and 
manganese. 
■■  Palladium  with  Hydrogen  at  a  High  Teynperature. — Heated 
palladium  is  readily  permeated  by  hydrogen  gas  by  a  process 
analogous  to  cementation.  Four  litres  of  hydrogen  per  minute 
was  passed  through  a  palladium  plate  1  m.m.  in  thickness  and  a 
square  metre  of  surface  at  a  bright  red  heat. 
The  Chemical  Properties  of  hydrogenium  distinguish  it  from 
gaseous  hydrogen.  The  palladium  alloy  precipitates  mercury  and 
cajomel  from  a  solution  of  corrosive  sublimate  without  any  disen- 
gagement of  hydrogen.  Hydrogenium  (alloyed  with  palladium), 
unites  with  chlorine  and  iodine  in  the  dark,  reduces  a  persalt  of 
iron  to  the  proto  state,  converts  red  into  yellow  prussiate  of  pot- 
ash, and  has  considerableMeoxidizing  power.  It  appears  to  be 
the  active  form  of  hydrogen,  as  ozone  is  of  oxygen. 
The  general  conclusions  arrived  at  are,  that  fully  charged  pal- 
ladium is  an  alloy  of  one  equivalent  of  each  metal ;  that  both  are 
solid,  metallic,  and  of  white  aspect ;  that  the  alloy  contains  about 
20  volumes  of  palladium  united  to  one  volume  of  hydrogenium  ; 
that  the  density  of  the  latter  is  about  2,  a  little  higher  than  mag- 
nesium, to  which  metal  it  is  supposed  to  bear  some  analogy  ;  that 
hydrogenium  has  a  certain  amount  of  tenacity,  and  possesses  the 
electrical  conductivity  of  a  metal ;  and,  finally,  that  hydrogenium 
takes  its  place  among  magnetic  metals.  The  latter  fact  in  con- 
nection with  the  appearance  of  hydrogen  in  meteoric  iron  opens 
out  a  subject  of  speculation. — Chem.  JVews,  Jan.  2dth,  and  read 
before  Royal  Soc.  Jan.  lith. 
