﻿IN 
  INCREASING 
  THE 
  INTENSITY 
  OP 
  ELECTRICITY. 
  227 
  

  

  at 
  the 
  middle 
  point, 
  and 
  when 
  a 
  pair 
  of 
  platina 
  wires 
  was 
  introduced 
  

   into 
  the 
  circuit 
  with 
  the 
  large 
  coil 
  and 
  immersed 
  in 
  a 
  solution 
  of 
  acid, 
  

   decomposition 
  took 
  place 
  in 
  the 
  liquid 
  at 
  each 
  rupture 
  of 
  contact, 
  as 
  

   was 
  shown 
  by 
  a 
  bubble 
  of 
  gas 
  given 
  off 
  at 
  each 
  wire. 
  It 
  must 
  be 
  

   recollected 
  that 
  the 
  shocks 
  and 
  the 
  decomposition 
  here 
  described 
  were 
  

   produced 
  by 
  the 
  electricity 
  from 
  a 
  single 
  pair 
  of 
  plates. 
  

  

  11. 
  The 
  contact 
  with 
  the 
  poles 
  of 
  the 
  battery 
  and 
  the 
  large 
  spiral 
  

   being 
  broken 
  in 
  a 
  vessel 
  containing 
  a 
  mixture 
  of 
  hydrogen 
  and 
  atmos- 
  

   pheric 
  air, 
  an 
  explosion 
  was 
  produced. 
  

  

  I 
  should 
  also 
  mention 
  that 
  the 
  spark 
  is 
  generally 
  attended 
  with 
  a 
  de- 
  

   flagration 
  of 
  the 
  mercury, 
  and 
  that 
  when 
  the 
  end 
  of 
  the 
  spiral 
  is 
  brought 
  

   in 
  contact 
  with 
  the 
  edge 
  of 
  the 
  copper 
  cup 
  or 
  the 
  plate 
  of 
  the 
  battery, 
  

   a 
  vivid 
  deflagration 
  of 
  the 
  metal 
  takes 
  place. 
  The 
  sides 
  of 
  the 
  cup 
  

   sometimes 
  give 
  a 
  spark 
  when 
  none 
  can 
  be 
  drawn 
  from 
  the 
  surface 
  of 
  

   the 
  mercury. 
  This 
  circumstance 
  requires 
  to 
  be 
  guarded 
  against 
  when 
  

   experimenting 
  on 
  the 
  comparative 
  intensities 
  of 
  sparks 
  from 
  different 
  

   arrangements. 
  If 
  the 
  battery 
  formerly 
  described 
  (fig. 
  1, 
  Plate 
  XII.) 
  

   be 
  arranged 
  as 
  a 
  calorimotor, 
  and 
  one 
  end 
  of 
  a 
  large 
  spiral 
  conductor 
  be 
  

   attached 
  to 
  one 
  pole, 
  and 
  the 
  other 
  end 
  drawn 
  along 
  the 
  edge 
  of 
  the 
  

   connector, 
  fig. 
  4, 
  a 
  series 
  of 
  loud 
  and 
  rapid 
  explosions 
  is 
  produced, 
  

   accompanied 
  by 
  a 
  brilliant 
  deflagration 
  of 
  the 
  metal, 
  and 
  this 
  takes 
  place 
  

   when 
  the 
  excitement 
  of 
  the 
  battery 
  is 
  too 
  feeble 
  to 
  heat 
  to 
  redness 
  a 
  

   small 
  platina 
  wire. 
  

  

  12. 
  A 
  number 
  of 
  experiments 
  were 
  made 
  to 
  determine 
  the 
  effect 
  of 
  

   introducing 
  a 
  cylinder 
  of 
  soft 
  iron 
  into 
  the 
  axis 
  of 
  the 
  flat 
  spiral, 
  in 
  

   reference 
  to 
  the 
  shock, 
  the 
  spark, 
  &c, 
  but 
  no 
  difference 
  could 
  be 
  ob- 
  

   served 
  with 
  the 
  large 
  spiral 
  conductor. 
  The 
  effect 
  of 
  the 
  iron 
  was 
  

   merged 
  in 
  that 
  of 
  the 
  spiral. 
  When, 
  however, 
  one 
  of 
  the 
  smaller 
  rib- 
  

   bons 
  was 
  formed 
  into 
  a 
  hollow 
  cylindrical 
  helix 
  of 
  about 
  nine 
  inches 
  

   long, 
  and 
  a 
  cylinder 
  of 
  soft 
  iron 
  an 
  inch 
  and 
  a 
  half 
  in 
  diameter 
  was 
  

   inserted, 
  the 
  spark 
  appeared 
  a 
  little 
  more 
  intense 
  than 
  without 
  the 
  iron. 
  

   The 
  obliquity 
  of 
  the 
  spires 
  in 
  this 
  case 
  was 
  unfavourable 
  to 
  their 
  mutual 
  

   action, 
  while 
  the 
  magnetism 
  w 
  T 
  as 
  greater 
  than 
  with 
  the 
  flat 
  spiral, 
  since 
  

   the 
  conductor 
  closely 
  surrounded 
  the 
  whole 
  length 
  of 
  the 
  cylinder. 
  

  

  I 
  would 
  infer, 
  from 
  these 
  experiments, 
  that 
  some 
  effects 
  heretofore 
  

   attributed 
  to 
  magneto-electric 
  action 
  are 
  chiefly 
  due 
  to 
  the 
  reaction 
  

  

  