﻿Chemistry 
  and 
  Physics. 
  67 
  

  

  ated 
  by 
  the 
  current 
  of 
  certain 
  voltaic 
  cells, 
  as 
  compared 
  with 
  

   the 
  amount 
  generated 
  by 
  the 
  chemical 
  action 
  going 
  on 
  in 
  the 
  

   cells 
  ; 
  in 
  order 
  to 
  determine 
  the 
  exact 
  relation 
  of 
  these 
  two 
  

   quantities. 
  The 
  heat 
  developed 
  by 
  the 
  current 
  was 
  ascertained 
  

   by 
  means 
  of 
  a 
  silver 
  voltameter 
  placed 
  together 
  with 
  the 
  cell, 
  in 
  a 
  

   calorimeter. 
  The 
  heat 
  evolved 
  by 
  the 
  chemical 
  action 
  was 
  deter- 
  

   mined 
  by 
  direct 
  calorimetric 
  means. 
  The 
  cells 
  examined 
  were 
  of 
  

   the 
  Daniell 
  and 
  the 
  De 
  la 
  Rue 
  forms, 
  three 
  experiments 
  being 
  

   made 
  with 
  each. 
  As 
  a 
  result 
  the 
  author 
  finds 
  that 
  with 
  the 
  Dan- 
  

   iell 
  cell, 
  the 
  heat 
  equivalent 
  of 
  the 
  current 
  is 
  greater 
  than 
  that 
  

   generated 
  chemically 
  ; 
  so 
  that 
  in 
  the 
  working 
  of 
  this 
  cell, 
  heat 
  is 
  

   absorbed. 
  On 
  the 
  other 
  hand 
  the 
  De 
  la 
  Rue 
  cell 
  shows 
  a 
  reverse 
  

   effect, 
  not 
  all 
  the 
  heat 
  proper 
  to 
  the 
  chemical 
  action 
  going 
  on 
  

   appearing 
  in 
  the 
  circuit. 
  But 
  in 
  this 
  case 
  the 
  author 
  observed 
  

   that 
  the 
  relative 
  amount 
  of 
  electrical 
  energy 
  increases 
  with 
  the 
  

   concentration 
  of 
  the 
  solution 
  in 
  the 
  cell. 
  These 
  results 
  confirm 
  

   substantially 
  those 
  of 
  Jahn. 
  — 
  Ann. 
  Phys. 
  Chem., 
  II, 
  xlvii, 
  103 
  ; 
  

   J. 
  Chem. 
  Soc, 
  lx, 
  513, 
  May, 
  1891. 
  g. 
  f. 
  b. 
  

  

  3. 
  On 
  the 
  Action 
  of 
  Heat 
  on 
  Carbon 
  Monoxide. 
  — 
  Berthelot 
  

   has 
  observed 
  that 
  when 
  carbon 
  monoxide 
  is 
  heated 
  in 
  a 
  glass 
  tube 
  

   to 
  500° 
  or 
  550°, 
  a 
  minute 
  quantity 
  — 
  three 
  or 
  lour 
  thousandths 
  

   — 
  of 
  carbon 
  dioxide 
  is 
  produced 
  ; 
  and 
  this 
  without 
  any 
  simul- 
  

   taneous 
  separation 
  of 
  carbon. 
  If, 
  however, 
  the 
  carbon 
  monoxide 
  

   be 
  passed 
  through 
  a 
  porcelain 
  tube, 
  and 
  the 
  temperature 
  of 
  this 
  

   be 
  raised 
  to 
  a 
  dull 
  or 
  even 
  a 
  bright 
  red 
  heat, 
  while 
  approximately 
  

   the 
  same 
  quantity 
  of 
  carbon 
  dioxide 
  is 
  observed 
  to 
  be 
  produced 
  

   as 
  before, 
  there 
  is 
  at 
  the 
  same 
  time 
  a 
  distinct 
  separation 
  of 
  carbon. 
  

   Hence 
  the 
  author 
  concludes 
  that 
  in 
  this 
  experiment 
  carbon 
  mon- 
  

   oxide 
  is 
  not 
  simply 
  dissociated, 
  but 
  is 
  at 
  the 
  same 
  polymerized 
  ; 
  

   and 
  that 
  the 
  product 
  of 
  this 
  polymerization 
  decomposes 
  into 
  

   carbon 
  dioxide 
  and 
  carbon 
  sub-oxide 
  according 
  to 
  the 
  equation 
  

   C 
  n 
  O 
  n 
  =C 
  m 
  _ 
  1 
  O 
  n 
  _ 
  2 
  + 
  C0 
  2 
  ; 
  which 
  sub-oxide 
  at 
  a 
  higher 
  temperature 
  

   yields 
  carbon 
  monoxide 
  and 
  free 
  carbon. 
  — 
  C. 
  P., 
  cxii, 
  594 
  Ber. 
  

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

  

  4. 
  On 
  the 
  Electro-metallurgy 
  of 
  Aluminum. 
  — 
  Minet 
  has 
  con- 
  

   tributed 
  further 
  details 
  concerning 
  the 
  reduction 
  of 
  aluminum 
  by 
  

   electrolytic 
  methods. 
  The 
  steel 
  crucible 
  is 
  now 
  made 
  smaller 
  

   and 
  is 
  provided 
  with 
  an 
  internal 
  lining 
  of 
  carbon 
  which 
  serves 
  as 
  

   the 
  negative 
  electrode. 
  The 
  difference 
  of 
  potential 
  between 
  the 
  

   two 
  electrodes 
  is 
  4*55 
  volts 
  and 
  the 
  yield 
  is 
  31-9 
  grams 
  of 
  alu- 
  

   minum 
  per 
  horse 
  power 
  per 
  hour, 
  or 
  31*3 
  horse 
  powers 
  per 
  hour 
  

   for 
  one 
  kilogram 
  of 
  aluminum. 
  The 
  author 
  believes 
  that 
  it 
  will 
  

   be 
  possible 
  to 
  reduce 
  the 
  difference 
  of 
  potential 
  to 
  4 
  volts 
  and 
  

   under 
  these 
  conditions 
  there 
  will 
  be 
  no 
  electrolysis 
  of 
  the 
  sodium 
  

   chloride 
  and 
  the 
  yield 
  will 
  reach 
  70 
  per 
  cent 
  of 
  the 
  theoretical 
  

   quantity. 
  The 
  loss 
  of 
  30 
  percent 
  is 
  due 
  to 
  the 
  action 
  of 
  the 
  fused 
  

   fluorides 
  on 
  the 
  aluminum 
  and 
  does 
  not 
  occur 
  when 
  aluminum 
  

   alloys 
  are 
  made, 
  since 
  in 
  this 
  case 
  the 
  electrolytic 
  cell 
  is 
  composed 
  

   of 
  the 
  other 
  metal 
  and 
  the 
  liberated 
  aluminum 
  at 
  once 
  combines 
  

   with 
  it. 
  — 
  C. 
  P., 
  cxii, 
  231; 
  J. 
  Chem. 
  Soc, 
  lx, 
  525, 
  May, 
  1891. 
  

  

  G. 
  F. 
  B. 
  

  

  