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  INFLUENCE 
  OF 
  A 
  SPIRAL 
  CONDUCTOR 
  

  

  on 
  each 
  other 
  of 
  the 
  several 
  spires 
  of 
  the 
  coil 
  which 
  surround 
  the 
  

   magnet. 
  

  

  13. 
  One 
  of 
  the 
  most 
  singular 
  results 
  in 
  this 
  investigation 
  was 
  first 
  

   obtained 
  in 
  operating 
  with 
  the 
  large 
  galvanic 
  battery 
  (fig. 
  2. 
  Plate 
  XXII.). 
  

   The 
  whole 
  instrument 
  was 
  arranged 
  as 
  a 
  calorimotor 
  of 
  eight 
  pairs,and 
  

   a 
  large 
  spiral 
  conductor 
  introduced 
  into 
  the 
  circuit 
  at 
  c 
  d, 
  while 
  a 
  piece 
  

   of 
  thick 
  copper 
  wire 
  about 
  five 
  inches 
  long 
  united 
  the 
  poles 
  at 
  a 
  b. 
  

   In 
  this 
  state 
  an 
  explosion 
  or 
  loud 
  snap 
  was 
  produced, 
  not 
  only 
  when 
  

   the 
  contact 
  was 
  broken 
  at 
  the 
  spiral, 
  but 
  also 
  when 
  one 
  end 
  of 
  the 
  

   short 
  wire 
  at 
  the 
  other 
  extremity 
  of 
  the 
  apparatus 
  was 
  drawn 
  from 
  its 
  

   cup. 
  All 
  the 
  other 
  short 
  movable 
  connectors 
  of 
  the 
  battery 
  gave 
  a 
  

   similar 
  result. 
  When 
  the 
  spiral 
  was 
  removed 
  from 
  the 
  circuit 
  and 
  a 
  

   short 
  wire 
  substituted, 
  no 
  effect 
  of 
  the 
  kind 
  was 
  produced. 
  From 
  this 
  

   experiment 
  it 
  appears 
  that 
  the 
  influence 
  of 
  the 
  spiral 
  is 
  exerted 
  through 
  

   at 
  least 
  eight 
  alternations 
  of 
  zinc, 
  acid 
  and 
  copper, 
  and 
  thus 
  gives 
  to 
  a 
  

   short 
  wire 
  at 
  the 
  other 
  extremity 
  of 
  the 
  circuit 
  the 
  power 
  of 
  producing 
  

   a 
  spark. 
  

  

  14. 
  The 
  influence 
  of 
  the 
  coil 
  was 
  likewise 
  manifest 
  when 
  the 
  zinc 
  

   and 
  copper 
  plates 
  of 
  a 
  single 
  pair 
  were 
  separated 
  from 
  each 
  other 
  to 
  

   the 
  distance 
  of 
  fourteen 
  inches 
  in 
  a 
  trough 
  without 
  partitions, 
  filled 
  

   with 
  diluted 
  acid. 
  Although 
  the 
  electrical 
  intensity 
  in 
  this 
  case 
  must 
  

   have 
  been 
  very 
  low, 
  yet 
  there 
  was 
  but 
  little 
  reduction 
  in 
  the 
  apparent 
  

   intensity 
  of 
  the 
  spark. 
  

  

  15. 
  The 
  spiral 
  conductor 
  produces, 
  however, 
  little 
  or 
  no 
  increase 
  of 
  

   effect 
  when 
  introduced 
  into 
  a 
  galvanic 
  circuit 
  of 
  considerable 
  intensity. 
  

   Thus 
  when 
  the 
  large 
  spiral 
  used 
  in 
  experiment 
  seventh, 
  eighth, 
  &c. 
  was 
  

   made 
  to 
  connect 
  the 
  poles 
  of 
  two 
  Cruikshank's 
  troughs, 
  each 
  containing 
  

   fifty-six 
  four 
  inch 
  plates, 
  no 
  greater 
  effect 
  was 
  perceived 
  than 
  with 
  a 
  

   short 
  thick 
  wire: 
  in 
  both 
  cases 
  in 
  making 
  the 
  contact 
  a 
  feeble 
  spark 
  

   was 
  given, 
  attended 
  with 
  a 
  slight 
  deflagration 
  of 
  the 
  mercury. 
  The 
  

   batteries 
  at 
  the 
  same 
  time 
  were 
  in 
  sufficiently 
  intense 
  action 
  to 
  give 
  a 
  

   disagreeable 
  shock. 
  It 
  is 
  probable, 
  however, 
  that 
  if 
  the 
  length 
  of 
  the 
  

   coil 
  were 
  increased 
  in 
  some 
  proportion 
  to 
  the 
  increase 
  of 
  intensity, 
  an 
  

   increased 
  effect, 
  would 
  still 
  be 
  produced. 
  

  

  In 
  operating 
  with 
  the 
  apparatus 
  described 
  in 
  the 
  last 
  experiment, 
  a 
  

   phenomenon 
  was 
  observed 
  in 
  reference 
  to 
  the 
  action 
  of 
  the 
  battery 
  

  

  