﻿500 
  Dr. 
  W. 
  Manser 
  gh 
  Varley 
  on 
  Magnetism 
  induced 
  

  

  Finally 
  the 
  tube 
  was 
  gently 
  shaken, 
  and 
  immediately 
  the 
  

   gaseous 
  ammonia 
  vanished 
  leaving 
  only 
  a 
  very 
  small 
  air- 
  

   bubble. 
  

  

  The 
  experiment 
  was 
  repeated, 
  the 
  initial 
  volume 
  of 
  solution 
  

   o£ 
  ammonia 
  being 
  7'5 
  c. 
  c, 
  and 
  the 
  volume 
  of 
  distilled 
  

   water 
  5*5 
  c.c, 
  

  

  The 
  initial 
  volume 
  of 
  gaseous 
  ammonia 
  (at 
  0° 
  and 
  760 
  mm. 
  

   dry) 
  was 
  38*2 
  c. 
  c. 
  The 
  volume 
  after 
  addition 
  of 
  the 
  water 
  

   was 
  34*8 
  c.c., 
  which 
  three 
  hours 
  standing 
  reduced 
  to 
  23*1 
  c.c. 
  

  

  After 
  the 
  lapse 
  of 
  a 
  further 
  ten 
  hours 
  the 
  volume 
  fell 
  to 
  

   7*13 
  c. 
  c, 
  which 
  instantly 
  disappeared 
  on 
  slight 
  shaking. 
  

  

  The 
  experiments 
  are 
  being 
  continued, 
  and 
  the 
  results 
  are 
  

   far-reaching. 
  

  

  The 
  Laboratory, 
  New 
  Maiden, 
  Surrey, 
  

   25th 
  March, 
  1902. 
  

  

  LVIII. 
  On 
  the 
  Magnetism 
  induced 
  in 
  Iron 
  by 
  Rapidly 
  Oscil- 
  

   lating 
  Current-fields. 
  By 
  W. 
  Mansekgh 
  Varley, 
  B.Sc, 
  

   Ph.I)., 
  1851 
  Exhibition 
  Scholar*. 
  

  

  1. 
  A 
  S 
  long 
  ago 
  as 
  1827 
  Savary 
  t 
  noticed 
  that 
  a 
  steel 
  needle 
  

   XlL 
  could 
  be 
  magnetized 
  by 
  putting 
  it 
  in 
  the 
  neighbour- 
  

   hood 
  of 
  a 
  wire 
  through 
  which 
  a 
  leyden-jar 
  was 
  discharged, 
  

   and 
  some 
  years 
  later 
  similar 
  experiments 
  led 
  Henry 
  X 
  to 
  

   suspect 
  the 
  oscillatory 
  character 
  of 
  the 
  leyden-jar 
  discharge. 
  

   Still 
  later, 
  however, 
  both 
  Feddersen§ 
  and 
  Hertz 
  || 
  expressed 
  

   the 
  opinion 
  that 
  iron 
  is 
  not 
  magnetized 
  by 
  rapidly 
  oscillating 
  

   fields: 
  but 
  Thomson 
  H, 
  Trowbridge**, 
  Klemencictf, 
  Mar- 
  

   chandJJ, 
  and 
  Hemsalech§§ 
  have 
  shown 
  by 
  various 
  methods 
  

   that 
  when 
  iron 
  is 
  placed 
  in 
  such 
  an 
  oscillating 
  held, 
  there 
  is 
  

   an 
  increase 
  in 
  the 
  energy 
  absorbed 
  such 
  as 
  can 
  only 
  be 
  

   accounted 
  for 
  on 
  the 
  supposition 
  that 
  the 
  iron 
  is 
  rapidly 
  

   magnetized 
  and 
  demagnetized. 
  St. 
  John|||| 
  also 
  has 
  com- 
  

   pared 
  the 
  self-inductions 
  of 
  similar 
  iron 
  and 
  copper 
  circuits, 
  

  

  * 
  Communicated 
  by 
  Prof. 
  J. 
  J. 
  Thomson. 
  

  

  f 
  F. 
  Savary, 
  Pogg. 
  Ann. 
  x. 
  p. 
  73 
  (1827), 
  and 
  Ann. 
  de 
  Chim. 
  et 
  de 
  

   Phys. 
  xxxiv. 
  p. 
  5 
  (1827). 
  

  

  % 
  Jos. 
  Henry, 
  Lodge's 
  ' 
  Modern 
  Views 
  of 
  Electricity,' 
  p. 
  370 
  (1899), 
  

   or 
  Fleming's 
  ' 
  Alternate 
  Current 
  Transformer,' 
  vol. 
  i. 
  p. 
  223. 
  

  

  § 
  W. 
  Feddersen, 
  Pogg. 
  Ann. 
  cviii. 
  p. 
  497 
  (1859). 
  

  

  |l 
  H. 
  Hertz, 
  Wied. 
  Ann. 
  xxxiv. 
  p. 
  558 
  (1888). 
  

  

  f 
  J. 
  J. 
  Thomson, 
  Phil. 
  Mag. 
  xxxii. 
  p. 
  445 
  (1891). 
  

  

  ** 
  J. 
  Trowbridge, 
  Phil. 
  Mag. 
  xxxii. 
  p. 
  504 
  (1891). 
  

  

  tt 
  I. 
  Klemencic, 
  Wien. 
  Ber. 
  ciii. 
  p. 
  205 
  (1894;'; 
  civ. 
  p. 
  724 
  (1895) 
  ; 
  

   cvii. 
  p. 
  330 
  (1898). 
  

  

  XX 
  E. 
  W. 
  Marchand, 
  ' 
  Nature,' 
  lxii. 
  p. 
  413 
  (1900). 
  

  

  §§ 
  Hemsalech, 
  Comptes 
  Hendus, 
  cxxxii. 
  p. 
  917 
  (1901). 
  

  

  HII 
  C. 
  E. 
  St. 
  John, 
  Phil. 
  Mag. 
  xxxviii. 
  p. 
  425 
  (1894). 
  

  

  