﻿Geology 
  and 
  Mineralogy. 
  76 
  

  

  in 
  gold 
  showed 
  normal 
  dispersion, 
  while 
  burned-in 
  platinum 
  

   exhibited 
  anomalous 
  dispersion. 
  Steel 
  and 
  nickel-steel 
  showed 
  

   anomalous 
  dispersion 
  ; 
  brass, 
  highly 
  polished, 
  normal 
  dispersion. 
  — 
  

   Wied. 
  Ann., 
  No. 
  5, 
  1899, 
  pp. 
  46-73. 
  j. 
  t. 
  

  

  8. 
  Electrical 
  Waves. 
  — 
  Albekt 
  Neugschwender 
  has 
  described 
  

   a 
  new 
  method 
  of 
  detecting 
  electric 
  waves, 
  which 
  consists 
  in 
  using 
  

   as 
  receiver 
  two 
  pieces 
  of 
  tin 
  foil 
  separated 
  by 
  a 
  fine 
  line. 
  This 
  

   Rhigi 
  resonator 
  is 
  placed 
  in 
  one 
  branch 
  of 
  a 
  Wheatstone 
  bridge. 
  

   The 
  fine 
  line 
  is 
  moistened 
  by 
  various 
  electrolytes 
  or 
  by 
  vapors. 
  

   When 
  the 
  electric 
  waves 
  impinge 
  on 
  the 
  slit 
  its 
  resistance 
  is 
  

   greatly 
  increased, 
  in 
  some 
  cases 
  rising 
  from 
  80 
  to 
  90,000 
  ohms. 
  

   The 
  author 
  has 
  carefully 
  investigated 
  the 
  phenomena, 
  and 
  finds 
  

   that 
  the 
  waves 
  disturb 
  the 
  formation 
  of 
  fine 
  filaments 
  of 
  metal 
  

   in 
  the 
  electrolytes 
  (Metallbaumchen), 
  which 
  are 
  essential 
  for 
  good 
  

   conductivity. 
  — 
  Wied. 
  Ajin., 
  No. 
  5, 
  1899, 
  pp. 
  92-98. 
  j. 
  t. 
  

  

  9. 
  Ether 
  Movements. 
  — 
  G. 
  Mil 
  discusses 
  analytically 
  the 
  ques- 
  

   tion 
  of 
  the 
  fixed 
  and 
  moving 
  ether 
  in 
  relation 
  to 
  Poynting's 
  

   hypothesis. 
  In 
  order 
  to 
  ascertain 
  a 
  possible 
  limit, 
  he 
  arranged 
  

   condensers 
  in 
  a 
  powerful 
  magnetic 
  field 
  in 
  such 
  manner 
  that 
  the 
  

   electrostatic 
  lines 
  ot 
  force 
  were 
  at 
  right 
  angles 
  to 
  the 
  magnetic 
  

   lines, 
  and 
  by 
  means 
  of 
  an 
  interferential 
  refractometer 
  tested 
  

   whether 
  a 
  light 
  ray 
  suffered 
  any 
  change 
  in 
  velocity. 
  A 
  negative 
  

   result 
  was 
  obtained. 
  This, 
  according 
  to 
  the 
  author, 
  does 
  not 
  

   show 
  that 
  the 
  ether 
  is 
  fixed, 
  although 
  the 
  value 
  for 
  yu 
  (inertia 
  of 
  

   ether 
  particles) 
  was 
  fi^ 
  10"'°, 
  which 
  is 
  very 
  small. 
  — 
  Wied. 
  Ann., 
  

   No. 
  5, 
  1899, 
  pp. 
  129-134. 
  j. 
  t. 
  

  

  10. 
  'Verliandlnngen 
  der 
  Deidschen 
  Physikalischen 
  Gesellschaft. 
  

   — 
  Physicists 
  will 
  be 
  interested 
  in 
  the 
  announcement 
  recently 
  made 
  

   by 
  the 
  publishing 
  house 
  of 
  Johann 
  Ambrosius 
  Barth, 
  in 
  Leipzig, 
  

   that 
  it 
  is 
  proposed 
  to 
  publish 
  the 
  Transactions 
  of 
  the 
  German 
  

   Physical 
  Society, 
  successor 
  to 
  the 
  Physical 
  Society 
  of 
  Berlin, 
  in 
  

   successive 
  numbers, 
  published 
  as 
  called 
  for, 
  and 
  for 
  which 
  an 
  

   annual 
  subscription 
  price 
  of 
  4 
  marks 
  will 
  be 
  charged. 
  The 
  first 
  

   number 
  (pp. 
  1-48) 
  has 
  already 
  been 
  issued. 
  

  

  II. 
  Geology 
  and 
  Minekalogy. 
  

  

  1. 
  United 
  States 
  Geological 
  Suruey, 
  Eighteenth 
  Annual 
  Re- 
  

   port, 
  1896-97. 
  — 
  The 
  bound 
  volumes 
  of 
  the 
  Eighteenth 
  Annual 
  

   Report 
  have 
  been 
  issued 
  in 
  five 
  volumes. 
  Part 
  I, 
  Director'' 
  s 
  Re- 
  

   port, 
  including 
  Triangulation 
  and 
  spirit 
  leveling, 
  pp. 
  440. 
  Part 
  

   11, 
  Papers 
  chiefly 
  of 
  a 
  theoretic 
  nature, 
  pp. 
  653. 
  Part 
  III, 
  

   Economic 
  geology, 
  pp. 
  861. 
  Part 
  lY, 
  Hydrography, 
  pp. 
  756. 
  

   Part 
  V, 
  Mineral 
  resources 
  of 
  U. 
  S. 
  for 
  1896. 
  Each 
  of 
  the 
  vol- 
  

   umes 
  is 
  illustrated 
  by 
  numerous 
  plates 
  and 
  maps. 
  The 
  contents 
  

   of 
  the 
  second 
  volume 
  have 
  in 
  part 
  been 
  already 
  noticed 
  in 
  this 
  

   Journal, 
  as 
  they 
  were 
  issued 
  in 
  pamphlet 
  form. 
  Special 
  notice 
  at 
  

   this 
  time 
  should 
  be 
  drawn, 
  however, 
  to 
  a 
  few 
  not 
  heretofore 
  

   mentioned 
  : 
  

  

  