﻿378 
  Scientific 
  Intelligence. 
  

  

  The 
  magnetic 
  deflectibilit} 
  T 
  of 
  the 
  Becquerel 
  rays 
  cannot 
  but 
  be 
  

   considered 
  to 
  be 
  a 
  most 
  characteristic 
  property. 
  And 
  the 
  above 
  

   result 
  appears 
  to 
  make 
  it 
  tolerably 
  certain 
  that 
  the 
  Rontgen 
  rays 
  

   do 
  not 
  possess 
  this 
  property. 
  It 
  is 
  to 
  be 
  concluded, 
  therefore, 
  

   that 
  the 
  Becquerel 
  rays 
  are, 
  after 
  all, 
  essentially 
  different 
  in 
  char- 
  

   acter 
  from 
  the 
  Rontgen 
  rays." 
  — 
  JProc. 
  Boy. 
  Soc, 
  lxvi, 
  75. 
  

  

  3. 
  Becquerel 
  Bays. 
  Confirmation 
  of 
  the 
  Material 
  Theory 
  of 
  

   the 
  (leviable 
  Bays 
  of 
  Baclium. 
  — 
  Radium 
  has 
  again 
  occupied 
  the 
  

   post 
  of 
  honor 
  during 
  the 
  last 
  fortnight. 
  After 
  the 
  discoveries 
  of 
  

   which 
  we 
  have 
  recently 
  written, 
  a 
  quiet 
  time 
  was 
  to 
  be 
  expected 
  ; 
  

   such, 
  however, 
  has 
  not 
  been 
  the 
  case, 
  and 
  far 
  from 
  diminishing 
  in 
  

   importance, 
  the 
  facts 
  made 
  known 
  during 
  these 
  last 
  few 
  weeks 
  

   surpass 
  in 
  novelty 
  and 
  interest 
  all 
  those 
  of 
  which 
  the 
  discovery 
  

   has 
  already 
  excited 
  such 
  enthusiasm. 
  

  

  For 
  some 
  time 
  we 
  have 
  been 
  working 
  in 
  the 
  dark, 
  and 
  were 
  

   vainly 
  endeavouring 
  to 
  find 
  the 
  point 
  whence 
  light 
  would 
  come. 
  

   We 
  already 
  knew 
  that 
  the 
  emission 
  of 
  radium 
  did 
  not 
  agree 
  with 
  

   our 
  ideas 
  on 
  ether 
  waves 
  ; 
  but 
  the 
  facts 
  already 
  known 
  did 
  not 
  yet 
  

   warrant 
  us 
  in 
  believing 
  that 
  it 
  was 
  of 
  a 
  material 
  nature. 
  A 
  

   decisive 
  experiment 
  of 
  this 
  kind, 
  as 
  we 
  shall 
  see 
  immediately, 
  has 
  

   just 
  been 
  made 
  by 
  M. 
  Curie 
  ; 
  however, 
  to 
  properly 
  understand 
  

   and 
  appreciate 
  it, 
  it 
  is 
  necessary 
  to 
  consider 
  the 
  question 
  a 
  little 
  

   further 
  back. 
  

  

  In 
  a 
  paper 
  recently 
  presented 
  to 
  the 
  Academy, 
  M. 
  Becquerel 
  

   has 
  pointed 
  out 
  several 
  remarkable 
  facts 
  with 
  regard 
  to 
  the 
  

   propagation 
  of 
  the 
  emission 
  of 
  radium. 
  The 
  active 
  substance 
  

   was 
  contained 
  in 
  a 
  little 
  recess, 
  hollowed 
  in 
  a 
  lead 
  slab, 
  placed 
  

   directly 
  on 
  the 
  photographic 
  plate, 
  and 
  the 
  whole 
  was 
  placed 
  in 
  a 
  

   uniform 
  magnetic 
  field 
  parallel 
  to 
  the 
  plate. 
  Under 
  these 
  condi- 
  

   tions 
  the 
  impression 
  due 
  to 
  the 
  rays 
  emitted 
  from 
  below 
  upwards, 
  

   and 
  bent 
  back 
  on 
  to 
  the 
  photographic 
  plate 
  by 
  the 
  action 
  of 
  the 
  

   magnetic 
  field, 
  is 
  limited 
  on 
  the 
  side 
  of 
  its 
  source 
  by 
  an 
  elliptical 
  

   arc, 
  in 
  the 
  interior 
  of 
  which 
  no 
  photographic 
  action 
  can 
  be 
  ob- 
  

   served, 
  while 
  such 
  action 
  can 
  be 
  seen 
  diffused 
  gradually 
  towards 
  

   the 
  parts 
  farthest 
  distant 
  from 
  the 
  source. 
  The 
  rays 
  have 
  thus 
  

   described 
  the 
  arcs, 
  of 
  which 
  the 
  shortest 
  are 
  situated 
  in 
  the 
  plane 
  

   perpendicular 
  to 
  the 
  direction 
  of 
  the 
  field, 
  while 
  the 
  oblique 
  arcs 
  

   have 
  rays 
  of 
  much 
  greater 
  length. 
  

  

  The 
  aspect 
  alone 
  of 
  the 
  photographic 
  plate 
  shows 
  that 
  the 
  

   emission 
  is 
  complex, 
  since 
  the 
  same 
  field 
  acts 
  in 
  a 
  different 
  man- 
  

   ner 
  on 
  the 
  various 
  rays 
  emanating 
  from 
  the 
  source. 
  But 
  this 
  

   complexity 
  becomes 
  still 
  more 
  evident 
  if 
  we 
  interpose 
  screens 
  in 
  

   the 
  trajectory 
  of 
  the 
  rays. 
  Under 
  these 
  conditions 
  the 
  impression 
  

   nearest 
  to 
  the 
  source 
  is 
  suppressed, 
  the 
  line 
  of 
  light 
  recedes, 
  and 
  

   gets 
  farther 
  from 
  the 
  source 
  the 
  more 
  the 
  substance 
  is 
  absorbent. 
  

   We 
  thus 
  see 
  that 
  the 
  strongly 
  curved 
  rays 
  are 
  absorbed 
  more 
  

   than 
  the 
  others, 
  without 
  any 
  other 
  apparent 
  selection, 
  no 
  matter 
  

   what 
  the 
  screens 
  are 
  made 
  of. 
  

  

  Now 
  let 
  us 
  examine 
  this 
  characteristic 
  from 
  the 
  point 
  of 
  the 
  

   materialist 
  theory 
  of 
  the 
  rays, 
  and 
  let 
  us 
  suppose 
  that 
  the 
  parti- 
  

   cles 
  emitted 
  by 
  the 
  radium 
  have 
  different 
  speeds. 
  

  

  