﻿Chemistry 
  and 
  Physics. 
  423 
  

  

  density 
  of 
  the 
  gas 
  thus 
  purified 
  was 
  19 
  "95 
  and 
  the 
  ratio 
  of 
  its 
  

   specific 
  heats 
  was 
  1*65. 
  Its 
  volume 
  was 
  37 
  cubic 
  centimeters. 
  

   In 
  order 
  to 
  bring 
  about 
  the 
  combination 
  of 
  argon 
  with 
  other 
  sub- 
  

   stances, 
  the 
  author 
  used 
  the 
  silent 
  discharge, 
  since 
  he 
  had 
  found 
  

   it, 
  in 
  his 
  experience, 
  much 
  more 
  effective 
  than 
  the 
  spark 
  in 
  secur- 
  

   ing 
  the 
  permanence 
  of 
  unstable 
  compounds. 
  Thus 
  nitrogen 
  in 
  

   presence 
  of 
  hydrocarbon 
  vapors 
  gives 
  rise 
  under 
  these 
  conditions 
  

   to 
  the 
  most 
  varied 
  products 
  of 
  condensation 
  — 
  products, 
  too, 
  which 
  

   decompose 
  with 
  elevation 
  of 
  temperature; 
  while 
  under 
  the 
  

   influence 
  of 
  the 
  spark, 
  hydrogen 
  cyanide, 
  because 
  of 
  its 
  stability 
  

   at 
  high 
  temperatures, 
  is 
  the 
  sole 
  product. 
  Again 
  the 
  silent 
  dis- 
  

   charge, 
  acting 
  on 
  a 
  mixture 
  of 
  nitrogen 
  and 
  hydrogen, 
  pro- 
  

   duces 
  several 
  per 
  cent 
  of 
  ammonia, 
  while 
  the 
  spark 
  gives 
  

   only 
  infinitesimal 
  quantities. 
  Under 
  the 
  action 
  of 
  the 
  silent 
  

   discharge 
  nitrogen 
  reacts 
  with 
  water 
  vapor 
  to 
  produce 
  am- 
  

   monium 
  nitrite, 
  a 
  compound 
  which, 
  on 
  standing, 
  is 
  decom- 
  

   posed 
  at 
  the 
  ordinary 
  temperature. 
  Moreover 
  the 
  vapor 
  of 
  

   benzene 
  was 
  employed 
  for 
  the 
  first 
  experiment, 
  because 
  the 
  

   author 
  had 
  found 
  it 
  very 
  effective 
  in 
  the 
  case 
  of 
  nitrogen. 
  

   The 
  apparatus 
  used 
  was 
  that 
  already 
  employed 
  in 
  similar 
  experi- 
  

   ments 
  [Ann. 
  Chem. 
  Phys., 
  V, 
  x, 
  76-79, 
  1877), 
  and 
  the 
  conditions 
  

   were 
  those 
  described 
  in 
  the 
  author's 
  " 
  Essai 
  de 
  Mechanique 
  Chim- 
  

   ique," 
  the 
  silent 
  discharge 
  being 
  effected 
  with 
  the 
  variable 
  poten- 
  

   tial 
  producible 
  with 
  an 
  induction 
  coil. 
  With 
  this 
  apparatus 
  the 
  

   author 
  had 
  succeeded 
  in 
  bringing 
  about 
  the 
  direct 
  union 
  of 
  free 
  

   nitrogen 
  with 
  hydrocarbons, 
  carbohydrates 
  and 
  other 
  organic 
  

   substances. 
  On 
  submitting 
  the 
  mixture 
  of 
  argon 
  and 
  the 
  vapor 
  

   of 
  benzene 
  to 
  the 
  action 
  of 
  the 
  silent 
  discharge, 
  combination 
  took 
  

   place 
  though 
  with 
  more 
  difficulty 
  than 
  in 
  the 
  case 
  of 
  nitrogen. 
  

   The 
  action 
  is 
  accompanied 
  with 
  a 
  faint 
  violet 
  glow 
  visible 
  in 
  

   darkness. 
  In 
  one 
  of 
  the 
  five 
  experiments 
  there 
  was 
  finally 
  

   formed 
  a 
  fluorescent 
  substance 
  which 
  gave 
  out 
  a 
  magnificent 
  

   greenish 
  light 
  and 
  afforded 
  a 
  special 
  spectrum. 
  A 
  careful 
  quanti- 
  

   tative 
  experiment, 
  made 
  with 
  10 
  c. 
  c. 
  of 
  argon, 
  yielded 
  the 
  follow- 
  

   ing 
  results: 
  100 
  volumes 
  of 
  this 
  gas, 
  put 
  in 
  contact 
  with 
  a 
  few 
  

   drops 
  of 
  benzene 
  (by 
  which 
  its 
  volume 
  was 
  increased 
  about 
  one- 
  

   twentieth), 
  was 
  introduced 
  into 
  the 
  discharge-tube 
  and 
  subjected 
  

   to 
  the 
  discharge 
  for 
  ten 
  hours 
  under- 
  moderate 
  tensions. 
  After 
  

   removing 
  the 
  benzene 
  vapor 
  by 
  concentrated 
  sulphuric 
  acid, 
  the 
  

   remaining 
  gas 
  occupied 
  89 
  volumes 
  ; 
  showing 
  a 
  condensation 
  of 
  

   11 
  per 
  cent. 
  It 
  was 
  again 
  mixed 
  with 
  benzene 
  vapor 
  and 
  again 
  

   subjected 
  to 
  the 
  discharge, 
  much 
  higher 
  tensions 
  being 
  employed. 
  

   The 
  diminution 
  in 
  volume 
  was 
  much 
  more 
  rapid, 
  amounting 
  in 
  

   three 
  hours 
  to 
  25 
  per 
  cent. 
  The 
  64 
  remaining 
  volumes 
  was 
  

   mixed 
  anew 
  with 
  benzene 
  vapor 
  and 
  again 
  exposed 
  for 
  several 
  

   hours 
  to 
  the 
  discharge 
  under 
  still 
  hrgher 
  tensions. 
  There 
  remained 
  

   32 
  volumes 
  of 
  gas, 
  consisting 
  of 
  hydrogen 
  13*5, 
  benzene 
  vapor 
  1*5 
  

   and 
  argon 
  17'0 
  volumes. 
  So 
  that 
  of 
  100 
  volumes 
  of 
  argon, 
  ben- 
  

   zene 
  had 
  condensed 
  83 
  into 
  a 
  state 
  of 
  chemical 
  combination 
  under 
  

   the 
  action 
  of 
  the 
  silent 
  discharge 
  ; 
  or 
  about 
  five-sixths. 
  The 
  

  

  