﻿Chemistry 
  and 
  Physics. 
  481 
  

  

  disulphide 
  and 
  the 
  pentasulphide. 
  Concentrated 
  sulphuric 
  acid 
  

   dissolved 
  it 
  unchanged, 
  and 
  it 
  resembles 
  somewhat 
  pseudocyano- 
  

   gen 
  sulphide 
  C 
  3 
  N 
  3 
  S 
  3 
  H. 
  Nitrogen 
  pentasulphide 
  may 
  also 
  be 
  formed 
  

   by 
  the 
  action 
  of 
  nitrogen 
  sulphide 
  on 
  carbon 
  tetrachloride, 
  or 
  

   by 
  reducing 
  thiotrithiazyl 
  chloride 
  N 
  3 
  S 
  4 
  C1 
  suspended 
  in 
  methyl 
  

   alcohol 
  by 
  means 
  of 
  zinc 
  dust. 
  In 
  general 
  it 
  results 
  from 
  the 
  

   decomposition 
  of 
  nitrogen 
  sulphide 
  and 
  its 
  derivatives; 
  as 
  for 
  

   example 
  when 
  this 
  substance 
  is 
  exploded 
  by 
  friction, 
  when 
  its 
  

   compounds 
  with 
  the 
  halogens 
  or 
  with 
  nitrous 
  or 
  nitric 
  acid 
  are 
  

   boiled 
  with 
  water, 
  and 
  when 
  it 
  is 
  heated 
  cautiously 
  with 
  lead 
  

   oxide. 
  Nitrogen 
  pentasulphide 
  is 
  a 
  deep 
  red 
  liquid, 
  with 
  a 
  sp. 
  gr. 
  

   of 
  1*901 
  at 
  18°. 
  It 
  does 
  not 
  wet 
  glass, 
  is 
  partially 
  decomposed 
  

   when 
  distilled 
  even 
  under 
  diminished 
  pressure, 
  and 
  when 
  cooled 
  

   in 
  a 
  freezing 
  mixture 
  solidifies 
  to 
  a 
  crystalline 
  mass 
  resembling 
  

   iodine, 
  which 
  fuses 
  at 
  10°- 
  11°. 
  It 
  is 
  insoluble 
  in 
  water, 
  but 
  dis- 
  

   solves 
  in 
  most 
  organic 
  solvents, 
  its 
  solution 
  being 
  stable 
  when 
  

   protected 
  from 
  light. 
  Its 
  absorption 
  spectrum 
  is 
  characterized 
  

   by 
  a 
  broad 
  band 
  extending 
  from 
  the 
  D 
  line 
  into 
  the 
  blue. 
  If 
  a 
  

   minute 
  quantity 
  of 
  alcoholic 
  potash 
  or 
  soda 
  is 
  added 
  to 
  its 
  solu- 
  

   tion 
  in 
  alcohol, 
  an 
  intense 
  violet-red 
  coloration 
  is 
  produced 
  tran- 
  

   siently 
  ; 
  this 
  reaction 
  serving 
  to 
  detect 
  a 
  very 
  minute 
  quantity. 
  — 
  

   Zeitschr. 
  anorg. 
  Chem., 
  xiii, 
  200-208, 
  October, 
  1896. 
  g. 
  f. 
  b. 
  

  

  4. 
  On 
  the 
  Direct 
  Union 
  of 
  Carbon 
  and 
  Hydrogen. 
  — 
  In 
  Ber- 
  

   thelot's 
  experiments 
  on 
  the 
  action 
  of 
  carbon 
  on 
  hydrogen 
  at 
  high 
  

   temperatures, 
  the 
  only 
  positive 
  result 
  obtained 
  was 
  the 
  forma- 
  

   tion 
  of 
  acetylene 
  when 
  the 
  electric 
  arc 
  was 
  formed 
  between 
  car- 
  

   bon 
  terminals 
  in 
  an 
  atmosphere 
  of 
  hydrogen. 
  Bone 
  and 
  Jordan 
  

   have 
  re-investigated 
  this 
  subject, 
  using 
  for 
  the 
  purpose 
  two 
  differ- 
  

   ent 
  methods. 
  In 
  the 
  first 
  a 
  current 
  of 
  hydrogen 
  was 
  passed 
  over 
  

   carefully 
  purified 
  sugar-charcoal 
  contained 
  in 
  a 
  porcelain 
  tube 
  

   heated 
  in 
  a 
  Fletcher 
  furnace 
  to 
  about 
  1200°. 
  While 
  the 
  issuing 
  

   gas 
  contained 
  no 
  acetylene 
  or 
  other 
  unsaturated 
  hydrocarbon, 
  

   there 
  was 
  present 
  invariably 
  about 
  one 
  per 
  cent 
  of 
  a 
  saturated 
  

   hydrocarbon, 
  probably 
  methane. 
  In 
  the 
  second 
  method 
  an 
  elec- 
  

   tric 
  arc 
  was 
  formed 
  between 
  terminals 
  of 
  purified 
  carbon 
  in 
  an 
  

   atmosphere 
  of 
  hydrogen. 
  The 
  products 
  obtained 
  were 
  acetylene 
  

   and 
  methane. 
  Experiments 
  on 
  the 
  progress 
  of 
  the 
  reaction 
  

   showed 
  a 
  somewhat 
  rapid 
  production 
  of 
  both 
  gases 
  during 
  the 
  first 
  

   half 
  hour, 
  while 
  the 
  amounts 
  formed 
  subsequently 
  seemed 
  gradu- 
  

   ally 
  to 
  approach 
  a 
  limit. 
  Since 
  this 
  condition 
  of 
  equilibrium 
  

   between 
  hydrogen, 
  methane 
  and 
  acetylene 
  is 
  of 
  great 
  interest, 
  the 
  

   authors 
  produced 
  the 
  arc 
  in 
  an 
  atmosphere 
  either 
  of 
  methane 
  or 
  

   of 
  acetylene, 
  expecting 
  that 
  while 
  at 
  first 
  the 
  greater 
  part 
  of 
  the 
  

   methane 
  or 
  acetylene 
  would 
  be 
  decomposed, 
  there 
  would 
  finally 
  

   be 
  reached 
  a 
  condition 
  of 
  equilibrium 
  similar 
  to 
  that 
  obtained 
  in 
  

   the 
  experiment 
  with 
  hydrogen. 
  This 
  was 
  found 
  to 
  be 
  the 
  case. 
  

   The 
  authors 
  sum 
  up 
  their 
  results 
  as 
  follows 
  : 
  (1) 
  At 
  a 
  tempera- 
  

   ture 
  of 
  1200° 
  or 
  thereabouts, 
  carbon 
  unites 
  directly 
  with 
  hydrogen 
  

   to 
  form 
  methane, 
  no 
  acetylene 
  or 
  other 
  unsaturated 
  hydrocarbon 
  

   being 
  formed 
  at 
  this 
  temperature. 
  (2) 
  When 
  the 
  electric 
  arc 
  is 
  

  

  