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  Rayleigh 
  and 
  Ramsay 
  — 
  Argon, 
  a 
  New 
  Constituent, 
  etc. 
  

  

  The 
  series 
  of 
  elements 
  possessing 
  atomic 
  weights 
  near 
  40 
  

   are 
  : 
  — 
  

  

  Chlorine 
  35*5 
  

  

  Potassium 
  39-1 
  

  

  Calcium 
  _. 
  40*0 
  

  

  Scandium 
  44*0 
  

  

  There 
  can 
  be 
  no 
  doubt 
  that 
  potassium, 
  calcium, 
  and 
  scan- 
  

   dium 
  follow 
  legitimately 
  their 
  predecessors 
  in 
  the 
  vertical 
  

   columns, 
  lithium, 
  beryllium, 
  and 
  boron, 
  and 
  that 
  they 
  are 
  in 
  

   almost 
  certain 
  relation 
  with 
  rubidium, 
  strontium, 
  and 
  (but 
  not 
  

   so 
  certainly) 
  yttrium. 
  If 
  argon 
  be 
  a 
  single 
  element, 
  then 
  there 
  

   is 
  reason 
  to 
  doubt 
  whether 
  the 
  periodic 
  classification 
  of 
  the 
  

   elements 
  is 
  complete 
  ; 
  whether, 
  in 
  fact, 
  elements 
  may 
  not 
  

   exist 
  which 
  cannot 
  be 
  fitted 
  among 
  those 
  of 
  which 
  it 
  is 
  com- 
  

   posed. 
  On 
  the 
  other 
  hand, 
  if 
  argon 
  be 
  a 
  mixture 
  of 
  two 
  ele- 
  

   ments, 
  they 
  might 
  find 
  place 
  in 
  the 
  eighth 
  group, 
  one 
  after 
  

   chlorine 
  and 
  one 
  after 
  bromine. 
  Assuming 
  37 
  (the 
  approxi- 
  

   mate 
  mean 
  between 
  the 
  atomic 
  weights 
  of 
  chlorine 
  and 
  potas- 
  

   sium) 
  to 
  be 
  the 
  atomic 
  weight 
  of 
  the 
  lighter 
  element, 
  and 
  40 
  

   the 
  mean 
  atomic 
  weight 
  found, 
  and 
  supposing 
  that 
  the 
  second 
  

   element 
  has 
  an 
  atomic 
  weight 
  between 
  those 
  of 
  bromine, 
  80, 
  

   and 
  rubidium, 
  85*5, 
  viz 
  : 
  82, 
  the 
  mixture 
  should 
  consist 
  of 
  

   93'3 
  per 
  cent, 
  of 
  the 
  lighter, 
  and 
  6*7 
  per 
  cent, 
  of 
  the 
  heavier 
  

   element. 
  But 
  it 
  appears 
  improbable 
  that 
  such 
  a 
  high 
  per- 
  

   centage 
  as 
  6*7 
  of 
  a 
  heavier 
  element 
  should 
  have 
  escaped 
  detec- 
  

   tion 
  during 
  liquefaction. 
  

  

  If 
  it 
  be 
  supposed 
  that 
  argon 
  belongs 
  to 
  the 
  eighth 
  group, 
  

   then 
  its 
  properties 
  would 
  tit 
  fairly 
  well 
  with 
  what 
  might 
  be 
  

   anticipated. 
  For 
  the 
  series, 
  which 
  contains 
  

  

  Si„ 
  IV 
  , 
  P™- 
  dV 
  , 
  SfA* 
  1 
  , 
  and 
  Cl 
  2 
  ItoVn 
  , 
  

  

  might 
  be 
  expected 
  to 
  end 
  with 
  an 
  element 
  of 
  monatomic 
  mole- 
  

   cules, 
  of 
  no 
  valency, 
  i. 
  e. 
  incapable 
  of 
  forming 
  a 
  compound, 
  or 
  

   if 
  forming 
  one, 
  being 
  an 
  octad 
  ; 
  and 
  it 
  would 
  form 
  a 
  possible 
  

   transition 
  to 
  potassium, 
  with 
  its 
  monovalence, 
  on 
  the 
  other 
  

   hand. 
  Such 
  conceptions 
  are, 
  however, 
  of 
  a 
  speculative 
  nature 
  ; 
  

   yet 
  they 
  may 
  be 
  perhaps 
  excused, 
  if 
  they 
  in 
  any 
  way 
  lead 
  to 
  

   experiments 
  which 
  tend 
  to 
  throw 
  more 
  light 
  on 
  the 
  anomalies 
  

   of 
  this 
  curious 
  element. 
  

  

  In 
  conclusion, 
  it 
  need 
  excite 
  no 
  astonishment 
  that 
  argon 
  is 
  

   so 
  indifferent 
  to 
  reagents. 
  For 
  mercury, 
  although 
  a 
  mona- 
  

   tomic 
  element, 
  forms 
  compounds 
  which 
  are 
  by 
  no 
  means 
  stable 
  

   at 
  a 
  high 
  temperature 
  in 
  the 
  gaseous 
  state 
  ; 
  and 
  attempts 
  to 
  

   produce 
  compounds 
  of 
  argon 
  may 
  be 
  likened 
  to 
  attempts 
  to 
  

   cause 
  combination 
  between 
  mercury 
  gas 
  at 
  800° 
  and 
  other 
  ele- 
  

   ments. 
  As 
  for 
  the 
  physical 
  condition 
  of 
  argon, 
  that 
  of 
  a 
  gas, 
  

  

  