﻿66 
  Scientific 
  Intelligence. 
  

  

  line 
  of 
  hydrogen. 
  The 
  influence 
  of 
  mercury 
  at 
  very 
  low 
  tem- 
  

   peratures 
  was 
  also 
  investigated. 
  The 
  paper 
  is 
  a 
  valuable 
  contri- 
  

   bution 
  to 
  spectrum 
  analysis. 
  — 
  Wied. 
  Ann., 
  No. 
  10, 
  1899, 
  pp. 
  

   398-425. 
  j. 
  t. 
  

  

  13. 
  On 
  the 
  limit 
  of 
  hearing. 
  — 
  Rudolph 
  Koenig 
  in 
  an 
  opening 
  

   article 
  discusses 
  this 
  question, 
  whether 
  the 
  upper 
  limits 
  set 
  by 
  

   various 
  authors, 
  c 
  6 
  to 
  c 
  7 
  or 
  c 
  B 
  , 
  is 
  a 
  true 
  one. 
  On 
  account 
  of 
  the 
  

   psychological 
  questions 
  involved 
  in 
  taking 
  what 
  may 
  be 
  called 
  

   hearsay 
  evidence 
  — 
  of 
  observers 
  — 
  Koenig 
  resolved 
  to 
  study 
  the 
  

   subject 
  by 
  means 
  of 
  Kundt's 
  dust 
  figures. 
  The 
  paper 
  contains 
  

   numerous 
  plates 
  of 
  the 
  results 
  obtained, 
  which 
  are 
  remarkable 
  

   from 
  an 
  experimental 
  point 
  of 
  view, 
  and 
  the 
  author 
  promises 
  a 
  

   continuation 
  of 
  his 
  paper. 
  — 
  Wied. 
  Ann,, 
  No. 
  11, 
  1899, 
  pp. 
  626- 
  

   660. 
  j. 
  t. 
  

  

  14. 
  Rotating 
  bodies 
  in 
  electric 
  fields. 
  — 
  A. 
  Heydweiller 
  in 
  a 
  

   long 
  paper 
  discusses 
  the 
  phenomena 
  of 
  the 
  solution 
  of 
  bodies 
  in 
  

   electric 
  fields 
  of 
  greater 
  and 
  of 
  less 
  conductivity 
  than 
  the 
  bodies. 
  

   He 
  agrees 
  with 
  certain 
  other 
  investigators 
  in 
  finding 
  evidence 
  of 
  

   accelerating 
  or 
  retarding 
  forces, 
  due 
  to 
  changes 
  in 
  the 
  electric 
  

   fields. 
  His 
  investigations 
  lead 
  him 
  to 
  determination 
  of 
  the 
  elec- 
  

   trical 
  conductivity 
  of 
  air 
  at 
  different 
  pressures, 
  and 
  he 
  discusses 
  

   the 
  probable 
  effect 
  of 
  these 
  accelerating 
  or 
  retarding 
  forces 
  on 
  the 
  

   motion 
  of 
  the 
  sun 
  and 
  planets. 
  It 
  appears 
  to 
  him 
  that 
  the 
  motion 
  

   of 
  the 
  moon 
  may 
  be 
  appreciably 
  affected 
  by 
  these 
  electrical 
  

   forces. 
  — 
  Wied. 
  Ann., 
  No. 
  11, 
  1899, 
  pp. 
  531-575. 
  j. 
  t. 
  

  

  15. 
  Masses 
  of 
  ions 
  in 
  gases 
  at 
  low 
  pressures. 
  — 
  A 
  very 
  important 
  

   paper 
  was 
  presented 
  at 
  the 
  late 
  meeting 
  of 
  the 
  British 
  Associa- 
  

   tion 
  at 
  Dover 
  on 
  this 
  subject 
  by 
  Prof. 
  J. 
  J. 
  Thomson 
  and 
  a 
  fuller 
  

   account 
  is 
  now 
  published 
  in 
  the 
  Philosophical 
  Magazine. 
  It 
  is 
  

   believed 
  by 
  the 
  author 
  that 
  the 
  composition 
  of 
  a 
  gas 
  consists 
  in 
  the 
  

   detachment 
  from 
  the 
  atom 
  of 
  a 
  negative 
  ion 
  ; 
  this 
  negative 
  ion 
  

   being 
  the 
  same 
  for 
  all 
  gases, 
  while 
  the 
  mass 
  of 
  the 
  ion 
  is 
  only 
  a 
  

   small 
  portion 
  of 
  the 
  mass 
  of 
  an 
  atom 
  of 
  hydrogen. 
  This 
  nega- 
  

   tive 
  ion, 
  therefore, 
  becomes 
  of 
  the 
  utmost 
  importance 
  in 
  all 
  

   theories 
  of 
  electrical 
  action, 
  and 
  may 
  be 
  the 
  fundamental 
  quan- 
  

   tity 
  in 
  terms 
  of 
  which 
  all 
  electrical 
  process 
  can 
  be 
  expressed. 
  

   The 
  mass 
  of 
  an 
  atom 
  is 
  not 
  invariable. 
  Electrification 
  of 
  a 
  gas 
  

   consists 
  in 
  splitting 
  up 
  some 
  of 
  the 
  atoms 
  of 
  a 
  gas. 
  The 
  detached 
  

   corpuscles 
  act 
  like 
  negative 
  ions 
  ; 
  each 
  carrying 
  a 
  constant 
  nega- 
  

   tive 
  charge, 
  which 
  the 
  author 
  calls 
  the 
  unit 
  charge. 
  

  

  This 
  theory 
  is 
  carefully 
  elaborated 
  and 
  forms 
  the 
  most 
  import- 
  

   ant 
  contribution 
  to 
  this 
  subject 
  of 
  the 
  present 
  year. 
  — 
  Phil. 
  Mag., 
  

   Dec. 
  1899, 
  pp. 
  547-567. 
  J. 
  t. 
  

  

  