﻿Troivbridge 
  and 
  Richards 
  — 
  The 
  Spectra 
  of 
  Argon. 
  15 
  

  

  Art. 
  II. 
  — 
  The 
  Spectra 
  of 
  Argon; 
  by 
  John 
  Trowbridge 
  

   and 
  Theodore 
  William 
  Richards. 
  

  

  It 
  is 
  well 
  known 
  that 
  argon 
  possesses 
  at 
  least 
  two 
  marked 
  

   spectra 
  — 
  one, 
  termed 
  the 
  red, 
  which 
  is 
  chiefly 
  characterized 
  by 
  

   red 
  lines 
  ; 
  and 
  another 
  called 
  the 
  blue, 
  which, 
  as 
  its 
  name 
  sig- 
  

   nifies, 
  is 
  strongly 
  marked 
  by 
  blue 
  lines. 
  

  

  In 
  studying 
  these 
  spectra 
  by 
  means 
  of 
  a 
  high 
  tension 
  accu- 
  

   mulator, 
  we 
  have 
  been 
  led 
  to 
  observe 
  carefully 
  the 
  electrical 
  

   conditions 
  necessary 
  for 
  producing 
  them. 
  It 
  is 
  obvious 
  that 
  a 
  

   battery 
  of 
  a 
  large 
  number 
  of 
  cells 
  is 
  the 
  most 
  suitable 
  source 
  for 
  

   the 
  study 
  of 
  discharges 
  of 
  electricity 
  through 
  gases. 
  Especially 
  

   is 
  this 
  true 
  of 
  a 
  storage 
  battery 
  ; 
  for 
  the 
  readiness 
  with 
  which 
  it 
  

   can 
  be 
  charged 
  by 
  a 
  dynamo, 
  the 
  constancy 
  of 
  the 
  electro- 
  

   motive 
  force 
  (about 
  2*1 
  volts 
  per 
  cell), 
  the 
  ease 
  with 
  which 
  it 
  

   can 
  be 
  coupled 
  for 
  quantity 
  or 
  tension 
  ; 
  and 
  the 
  steadiness 
  of 
  

   the 
  discharge 
  afforded 
  by 
  it, 
  make 
  such 
  a 
  battery 
  far 
  superior 
  

   to 
  an 
  induction 
  coil 
  or 
  to 
  an 
  electrical 
  machine. 
  

  

  With 
  an 
  induction 
  coil 
  the 
  discharge 
  is 
  not 
  undirectional 
  

   and 
  is 
  affected 
  by 
  the 
  necessary 
  irregularities 
  of 
  the 
  break. 
  

   These 
  irregularities 
  make 
  themselves 
  felt 
  in 
  a 
  marked 
  degree 
  

   when 
  a 
  condenser 
  is 
  used 
  in 
  the 
  secondary 
  circuit. 
  The 
  elec- 
  

   trical 
  machine 
  gives 
  an 
  intermittent 
  current, 
  and 
  has 
  a 
  varying 
  

   capacity. 
  The 
  advantages 
  of 
  a 
  battery 
  for 
  the 
  study 
  of 
  the 
  

   discharge 
  of 
  electricity 
  through 
  gases 
  have 
  been 
  pointed 
  out 
  by 
  

   De 
  la 
  Rue 
  and 
  Miller 
  and 
  by 
  fiittorf."* 
  These 
  investigators 
  

   worked 
  with 
  voltaic 
  cells 
  which 
  were 
  not 
  constant 
  and 
  which 
  

   required 
  great 
  oversight 
  and 
  continual 
  renewals. 
  In 
  our 
  

   investigations 
  we 
  are 
  using 
  a 
  lead 
  accumulator 
  of 
  the 
  Flante 
  

   type 
  ; 
  and 
  we 
  lind 
  it 
  highly 
  advantageous 
  for 
  spectroscopic 
  

   work 
  ; 
  for 
  by 
  means 
  of 
  the 
  steady 
  current 
  afforded 
  by 
  it, 
  one 
  

   can 
  study 
  the 
  spectra 
  of 
  gases 
  under 
  especially 
  good 
  conditions. 
  

  

  Our 
  battery 
  consists 
  of 
  five 
  thousand 
  cells, 
  so 
  arranged 
  that 
  

   they 
  may 
  be 
  disconnected 
  and 
  wholly 
  reconnected 
  in 
  any 
  

   desired 
  manner 
  in 
  less 
  than 
  a 
  minute. 
  The 
  electromotive 
  

   force 
  of 
  the 
  complete 
  series 
  is 
  somewhat 
  over 
  ten 
  thousand 
  

   volts, 
  but 
  when 
  the 
  cells 
  are 
  connected 
  for 
  quantity, 
  they 
  may 
  

   be 
  readily 
  charged 
  by 
  means 
  of 
  a 
  dynamo 
  giving 
  a 
  tension 
  of 
  

   only 
  sixty 
  volts. 
  The 
  insulation 
  of 
  the 
  terminals 
  of 
  tnis 
  bat- 
  

   tery 
  was 
  a 
  matter 
  of 
  some 
  difficulty, 
  for 
  even 
  dry 
  wood 
  allows 
  

   considerable 
  leakage 
  from 
  one 
  case 
  of 
  cells 
  to 
  another 
  ; 
  but 
  by 
  

   the 
  plentiful 
  use 
  of 
  paraffin, 
  mica, 
  and 
  vulcanite, 
  the 
  problem 
  

   was 
  solved 
  with 
  reasonable 
  success. 
  The 
  discharge 
  from 
  only 
  

   a 
  very 
  small 
  fraction 
  of 
  the 
  battery 
  produced 
  a 
  most 
  uncom- 
  

  

  * 
  Ann. 
  der 
  Fhys. 
  und 
  Chem. 
  (N. 
  F.), 
  vol. 
  vii, 
  1879, 
  p. 
  553. 
  

  

  