﻿170 
  Scientific 
  Intelligence. 
  

  

  of 
  lead 
  oxide 
  and 
  lead 
  sulphate. 
  This 
  plate 
  is 
  made 
  to 
  form 
  the 
  

   cathode 
  and 
  a 
  plate 
  of 
  platinum 
  the 
  anode 
  in 
  a 
  solution 
  of 
  sulphuric 
  

   acid. 
  The 
  following 
  are 
  the 
  results 
  obtained 
  : 
  The 
  first 
  action 
  on 
  

   the 
  plates 
  is 
  to 
  convert 
  the 
  lead 
  oxide 
  into 
  sulphate. 
  Then 
  the 
  

   hydrogen 
  evolved 
  in 
  the 
  electrolysis 
  reduces 
  this 
  lead 
  sulphate 
  

   forming 
  metallic 
  lead 
  and 
  sulphuric 
  acid. 
  The 
  metallic 
  lead 
  thus 
  

   freshly 
  reduced 
  attacks 
  the 
  sulphuric 
  acid, 
  evolving 
  hydrogen 
  

   and 
  forming 
  lead 
  sulphate 
  again 
  ; 
  these 
  reciprocal 
  processes 
  

   continuing 
  until 
  a 
  condition 
  of 
  equilibrium 
  is 
  reached 
  and 
  the 
  

   cell 
  is 
  charged. 
  This 
  local 
  action 
  it 
  is 
  which 
  has 
  led 
  Streintz 
  and 
  

   others 
  erroneously 
  to 
  conclude 
  that 
  hydrogen 
  is 
  occluded 
  in 
  the 
  

   lead 
  plate. 
  — 
  Monatsb. 
  ix, 
  433 
  ; 
  J. 
  Chem. 
  fioc, 
  lx, 
  514, 
  May, 
  

   1891. 
  G. 
  F. 
  B. 
  

  

  2. 
  On 
  the 
  Dead 
  Space 
  in 
  Chemical 
  Reactions. 
  — 
  A 
  third 
  paper 
  

   has 
  been 
  published 
  by 
  Liebreich 
  on 
  the 
  dead 
  space 
  in 
  chemical 
  

   reactions. 
  The 
  appearance 
  of 
  this 
  dead 
  space 
  depends 
  in 
  the 
  

   view 
  of 
  the 
  author 
  upon 
  the 
  less 
  mobility 
  of 
  the 
  molecules 
  at 
  the 
  

   surfaces 
  of 
  liquids; 
  a 
  fact 
  which 
  he 
  seems 
  to 
  have 
  proved 
  by 
  a 
  

   series 
  of 
  interesting 
  experiments. 
  From 
  this 
  it 
  follows 
  that 
  the 
  

   surfaces 
  of 
  liquids 
  oppose 
  resistance 
  to 
  the 
  motion 
  of 
  solid 
  bodies 
  

   against 
  them, 
  when 
  driven 
  by 
  a 
  slight 
  force, 
  in 
  the 
  same 
  way 
  as 
  

   a 
  solid 
  wall 
  would 
  do. 
  Such 
  phenomena 
  may 
  be 
  produced 
  when 
  

   one 
  liquid 
  is 
  allowed 
  to 
  rise 
  through 
  another 
  of 
  less 
  density, 
  in 
  

   case 
  the 
  friction-coefficient 
  of 
  the 
  liquids 
  is 
  sufficiently 
  large. 
  

   The 
  author 
  abundantly 
  shows 
  how 
  by 
  the 
  application 
  of 
  different 
  

   meniscus-shaped 
  forms, 
  the 
  shape 
  of 
  the 
  entering 
  liquid 
  currents 
  

   suffers 
  changes 
  ; 
  while 
  in 
  a 
  certain 
  sense 
  it 
  adapts 
  itself 
  to 
  them. 
  

   In 
  this 
  way 
  phenomena 
  can 
  be 
  obtained 
  quite 
  analogous 
  to 
  those 
  

   which 
  are 
  observed 
  in 
  the 
  dead 
  space 
  in 
  chemical 
  reactions. 
  — 
  

   Ber. 
  Ah. 
  Berl, 
  1890,1239; 
  JBer. 
  Berl. 
  Chem. 
  Ges., 
  xxiv, 
  (Ref.) 
  

   301, 
  April, 
  1891. 
  G. 
  e. 
  b. 
  

  

  3. 
  A 
  new 
  Reaction 
  of 
  Carbon 
  monoxide. 
  — 
  Berthelot 
  has 
  

   observed 
  that 
  a 
  solution 
  of 
  silver 
  nitrate, 
  to 
  which 
  has 
  been 
  

   added 
  just 
  enough 
  ammonia 
  to 
  redissolve 
  the 
  precipitate 
  at 
  first 
  

   formed, 
  becomes 
  colored 
  brown 
  when 
  a 
  current 
  of 
  carbon 
  mon- 
  

   oxide 
  is 
  passed 
  through 
  it 
  or 
  when 
  an 
  aqueous 
  solution 
  of 
  the 
  gas 
  

   is 
  added 
  to 
  it, 
  even 
  in 
  the 
  cold. 
  On 
  heating 
  it 
  becomes 
  darker 
  

   and 
  a 
  precipitate 
  is 
  thrown 
  down. 
  — 
  C. 
  R., 
  cxii, 
  597; 
  Ber. 
  Berl. 
  

   Chem. 
  Ges., 
  xxiv, 
  (Ref.) 
  348, 
  May, 
  1891. 
  g. 
  f. 
  b. 
  

  

  II. 
  Geology. 
  

  

  1. 
  On 
  the 
  Relations 
  of 
  the 
  Eastern 
  Sandstone 
  of 
  Keweenaw 
  

   Point 
  to 
  the 
  Lower 
  Silurian 
  Limestone 
  / 
  by 
  M. 
  E. 
  Wadsworth. 
  

   (Communicated). 
  — 
  One 
  of 
  the 
  assistants 
  (Mr. 
  W. 
  L. 
  Honnold) 
  of 
  

   the 
  Michigan 
  Geological 
  Survey, 
  has 
  been 
  engaged 
  in 
  the 
  study 
  

   of 
  the 
  relations 
  of 
  the 
  limestone 
  west 
  of 
  L'anse 
  to 
  the 
  Eastern 
  or 
  

   supposed 
  Potsdam 
  Sandstone 
  of 
  the 
  Copper-bearing 
  range. 
  This 
  

   locality 
  is 
  described 
  in 
  Jackson's 
  Report, 
  1849, 
  pp. 
  399-452, 
  

   Foster 
  and 
  Whitney's 
  Report 
  Part 
  I, 
  1850, 
  pp. 
  117-119, 
  and 
  in 
  

  

  