﻿224 
  INFLUENCE 
  OF 
  A 
  SPIRAL 
  CONDUCTOR 
  

  

  this 
  case 
  it 
  is 
  only 
  necessary 
  to 
  wait 
  a 
  few 
  minutes 
  until 
  the 
  action 
  

   partially 
  subsides, 
  or 
  no 
  more 
  sparks 
  are 
  given 
  ; 
  if 
  the 
  long 
  wire 
  be 
  

   now 
  substituted, 
  a 
  spark 
  will 
  again 
  be 
  obtained. 
  The 
  effect 
  appears 
  

   somewhat 
  increased 
  by 
  coiling 
  the 
  wire 
  into 
  a 
  helix 
  ; 
  it 
  seems 
  also 
  to 
  

   depend 
  in 
  some 
  measure 
  on 
  the 
  length 
  and 
  thickness 
  of 
  the 
  wire. 
  I 
  

   can 
  account 
  for 
  these 
  phenomena 
  only 
  by 
  supposing 
  the 
  long 
  wire 
  to 
  

   become 
  charged 
  with 
  electricity, 
  which, 
  by 
  its 
  reaction 
  on 
  itself, 
  pro- 
  

   jects 
  a 
  spark 
  when 
  the 
  connection 
  is 
  broken."* 
  

  

  The 
  above 
  was 
  published 
  immediately 
  before 
  my 
  removal 
  from 
  

   Albany 
  to 
  Princeton, 
  and 
  new 
  duties 
  interrupted, 
  for 
  a 
  time, 
  the 
  fur- 
  

   ther 
  prosecution 
  of 
  the 
  subject. 
  I 
  have, 
  however, 
  been 
  able 
  during 
  

   the 
  past 
  year 
  to 
  resume 
  in 
  part 
  my 
  investigations, 
  and 
  among 
  others, 
  

   have 
  made 
  a 
  number 
  of 
  observations 
  and 
  experiments 
  which 
  develope 
  

   some 
  new 
  circumstances 
  in 
  reference 
  to 
  this 
  curious 
  phenomenon. 
  

  

  These, 
  though 
  not 
  as 
  complete 
  as 
  I 
  could 
  wish, 
  are 
  now 
  presented 
  

   to 
  the 
  Society, 
  with 
  the 
  belief 
  that 
  they 
  will 
  be 
  interesting 
  at 
  this 
  time 
  

   on 
  account 
  of 
  the 
  recent 
  publication 
  of 
  Mr 
  Faraday 
  on 
  the 
  same 
  sub- 
  

   ject. 
  

  

  The 
  experiments 
  are 
  not 
  given 
  in 
  the 
  precise 
  order 
  in 
  which 
  they 
  

   were 
  first 
  made, 
  but 
  in 
  that 
  which 
  I 
  deem 
  best 
  suited 
  to 
  render 
  them 
  

   easily 
  understood 
  ; 
  they 
  have, 
  however, 
  been 
  repeated 
  for 
  publication 
  

   in 
  almost 
  the 
  same 
  order 
  in 
  which 
  they 
  are 
  here 
  given. 
  

  

  1. 
  A 
  galvanic 
  battery, 
  consisting 
  of 
  a 
  single 
  plate 
  of 
  zinc 
  and 
  cop- 
  

   per, 
  and 
  exposing 
  one 
  and 
  a 
  half 
  square 
  feet 
  of 
  zinc 
  surface, 
  including 
  

   both 
  sides 
  of 
  the 
  plate, 
  was 
  excited 
  with 
  diluted 
  sulphuric 
  acid, 
  and 
  

   then 
  permitted 
  to 
  stand 
  until 
  the 
  intensity 
  of 
  the 
  action 
  became 
  nearly 
  

   constant. 
  The 
  poles 
  connected 
  by 
  a 
  piece 
  of 
  copper 
  bell 
  wire 
  of 
  the 
  

   ordinary 
  size 
  and 
  five 
  inches 
  long, 
  gave 
  no 
  spark 
  when 
  the 
  contact 
  was 
  

   broken. 
  

  

  2. 
  A 
  long 
  portion 
  of 
  wire, 
  from 
  the 
  same 
  piece 
  with 
  that 
  used 
  in 
  the 
  

   last 
  experiment, 
  was 
  divided 
  into 
  equal 
  lengths 
  of 
  fifteen 
  feet, 
  by 
  making 
  

   a 
  loop 
  at 
  each 
  division, 
  which 
  could 
  be 
  inserted 
  into 
  the 
  cups 
  of 
  mer- 
  

   cury 
  on 
  the 
  poles 
  of 
  the 
  battery. 
  These 
  loops 
  being 
  amalgamated 
  and 
  

   dipped 
  in 
  succession 
  into 
  one 
  of 
  the 
  cups 
  while 
  the 
  first 
  end 
  of 
  the 
  

  

  * 
  Silliman's 
  Journal, 
  vol. 
  22, 
  page 
  408. 
  

  

  