﻿454 
  Dr. 
  H. 
  S. 
  Allen 
  on 
  Molecular 
  

  

  Group 
  IV. 
  

  

  The 
  compounds 
  of 
  carbon 
  are 
  so 
  numerous 
  as 
  to 
  require 
  

   separate 
  consideration. 
  It 
  is 
  only 
  necessary 
  to 
  mention 
  for 
  

   the 
  sake 
  o£ 
  comparison 
  with 
  compounds 
  containing 
  other 
  

   elements 
  of 
  the 
  same 
  group, 
  that 
  for 
  carbon 
  tetrabromide 
  

   (N 
  = 
  146) 
  the 
  value 
  of 
  NV 
  is 
  5 
  x 
  20*5 
  x 
  10 
  12 
  , 
  and 
  for 
  carbon 
  

   trichloride 
  (C 
  2 
  C1 
  6 
  ) 
  the 
  value 
  is 
  4| 
  x 
  20'6 
  X 
  10 
  12 
  . 
  For 
  silicon, 
  

   titanium, 
  and 
  zirconium 
  only 
  a 
  few 
  results 
  can 
  be 
  given. 
  

  

  Group 
  IV. 
  

   Silicon 
  Compound 
  (N 
  = 
  14). 
  

  

  Name. 
  Formula. 
  N. 
  ^XlO' 
  12 
  . 
  NvXlO" 
  12 
  . 
  

  

  Silicon 
  

   tetrabromide 
  SiBr 
  4 
  154 
  0553 
  4x21-3 
  

  

  Titanium 
  Compounds 
  (N 
  = 
  22). 
  

  

  Titanium 
  

  

  tetrafluoride 
  TiF 
  4 
  58 
  T848 
  5x21-4 
  

  

  tetrabromide 
  (a) 
  TiBr 
  4 
  102 
  0*545 
  4x22-0 
  

  

  dioxide 
  Ti0 
  2 
  38 
  5536 
  10x210 
  

  

  (a) 
  Melting-point, 
  39° 
  C, 
  Duppa 
  (1856). 
  

  

  Zirconium 
  Compound 
  (N 
  = 
  40). 
  

   Zirconium 
  

   dioxide 
  Zr0 
  2 
  56 
  5283 
  14x2M 
  

  

  Disregarding 
  the 
  high 
  value 
  for 
  v 
  A 
  in 
  the 
  case 
  of 
  titanium 
  

   bromide, 
  for 
  which 
  no 
  modern 
  determination 
  of 
  the 
  melting- 
  

   point 
  is 
  recorded, 
  the 
  values 
  of 
  va 
  for 
  the 
  compounds 
  of 
  this 
  

   group 
  are 
  generally 
  higher 
  than 
  those 
  for 
  the 
  earlier 
  groups. 
  

   In 
  the 
  case 
  or! 
  the 
  lead 
  salts, 
  however, 
  a 
  lower 
  value 
  is 
  found 
  

   for 
  the 
  chloride, 
  bromide, 
  and 
  iodide; 
  but 
  the 
  close 
  agreement 
  

   between 
  the 
  values 
  of 
  the 
  product 
  "Nv 
  for 
  these 
  three 
  salts 
  

   deserves 
  special 
  notice, 
  as 
  also 
  the 
  agreement 
  for 
  the 
  oxide 
  

   and 
  the 
  sulphide. 
  

  

  

  Tin 
  

  

  Compounds 
  

  

  (N 
  = 
  

  

  :50). 
  

  

  

  Name. 
  

   Stannic 
  

  

  fluoride 
  

  

  iodide 
  , 
  

  

  oxide 
  

  

  Stannous 
  

  

  bromide 
  

  

  

  Formula. 
  

  

  SnF, 
  

   Snl 
  4 
  

  

  SdO, 
  

  

  SnBr 
  

  

  SnS 
  " 
  

  

  N. 
  

  

  86 
  

  

  262 
  

  

  66 
  

  

  120 
  

   66 
  

  

  *xio- 
  12 
  . 
  

  

  2-049 
  

   0-491 
  

   3-353 
  

  

  1-075 
  

   2-780 
  

  

  JN^Xl0- 
  ] 
  

  

  8^x20-7 
  

  

  6" 
  X 
  21-4 
  

  

  10|x21-l 
  

  

  6 
  X21-5 
  

  

  sulphide 
  , 
  

  

  

  9 
  X20-4 
  

  

  