﻿BicKEBTON, 
  — 
  On 
  Partial 
  Impact. 
  127 
  

  

  side, 
  and 
  the 
  heavier 
  on 
  the 
  inside 
  of 
  bodies, 
  ■ 
  Hence, 
  the 
  chief 
  elements 
  of 
  

   the 
  surface 
  of 
  bodies 
  may 
  reasonably 
  be 
  expected 
  to 
  be 
  hydrogen, 
  lithium, 
  

   carbon, 
  nitrogen, 
  oxygen, 
  magnesium, 
  sodium, 
  and 
  sulxohur. 
  All 
  these 
  

   elements, 
  except 
  lithium 
  (which 
  may 
  consequently 
  be 
  assumed 
  to 
  be 
  

   universally 
  rare), 
  are 
  the 
  common 
  elements 
  of 
  the 
  surface 
  of 
  bodies 
  ; 
  and 
  

   hydrogen, 
  the 
  highest 
  of 
  all 
  known 
  bodies, 
  is 
  the 
  most 
  common 
  of 
  all. 
  Is 
  

   not 
  the 
  element 
  of 
  1474 
  line, 
  which 
  is 
  found 
  outside 
  of 
  hydrogen 
  on 
  the 
  

   sun, 
  an 
  element 
  of 
  still 
  less 
  atomic 
  weight 
  than 
  hydrogen 
  ? 
  If 
  this 
  

   hyx^othesis 
  be 
  true, 
  then 
  it 
  is 
  reasonable 
  to 
  assume 
  that 
  diffused 
  hydrogen 
  

   must 
  fill 
  space. 
  This 
  would 
  account 
  for 
  the 
  retardation 
  of 
  comets 
  and 
  

   planets 
  without 
  the 
  assumption 
  of 
  an 
  ether 
  resistance. 
  It 
  thus 
  appears 
  

   that 
  the 
  molecular 
  motion 
  of 
  gases 
  may 
  become 
  one 
  of 
  mere 
  translation. 
  

   There 
  is 
  accordingly 
  a 
  continuity 
  of 
  heat 
  and 
  mechanical 
  motion. 
  It 
  is 
  

   reasonable 
  to 
  suppose, 
  that 
  at 
  a 
  certain 
  height 
  above 
  the 
  sun 
  the 
  general 
  

   motion 
  of 
  the 
  particles 
  of 
  hydrogen 
  may 
  become 
  more 
  or 
  less 
  parallel 
  ; 
  there 
  

   would 
  be 
  no 
  collisions 
  of 
  molecules, 
  and 
  consequently 
  no 
  luminosity 
  would 
  

   be 
  then 
  produced, 
  and 
  an 
  apparent 
  dissipation 
  of 
  the 
  protuberances 
  would 
  

   occur. 
  I 
  have 
  now 
  shown 
  the 
  most 
  striking 
  points 
  in 
  the 
  contrast 
  of 
  the 
  

   energy 
  of 
  different 
  cases 
  of 
  collision. 
  I 
  have 
  also 
  shoAvn 
  a 
  possible 
  reason 
  

   why 
  the 
  small 
  atomic 
  weight 
  elements 
  are 
  common 
  on 
  the 
  surface 
  of 
  

   bodies 
  ; 
  why 
  we 
  should 
  expect 
  to 
  find 
  hydrogen 
  on 
  the 
  surface 
  of 
  all 
  

   bodies, 
  such 
  as 
  the 
  sun 
  and 
  stars 
  ; 
  lastly, 
  that 
  hydrogen, 
  and 
  probably 
  the 
  

   unknown 
  element 
  of 
  the 
  sun, 
  may 
  be 
  the 
  resisting 
  substance 
  which 
  retards 
  

   the 
  motion 
  of 
  bodies 
  in 
  space. 
  

  

  On 
  the 
  Rotation 
  of 
  Systems, 
  

  

  It 
  does 
  not 
  seem 
  reasonable 
  to 
  expect 
  rapid 
  rotation 
  in 
  the 
  case 
  of 
  entire 
  

   coalescence 
  of 
  two 
  bodies, 
  as 
  only 
  the 
  resultant 
  of 
  the 
  two 
  original 
  rotations 
  

   will 
  tend 
  to 
  develope 
  this 
  motion. 
  But, 
  in 
  the 
  case 
  of 
  partial 
  collision, 
  we 
  

   must 
  have 
  a 
  rapid 
  rotation 
  of 
  the 
  mass, 
  as 
  each 
  of 
  the 
  two 
  bodies 
  from 
  

   which 
  it 
  was 
  formed 
  occupy 
  chiefly 
  one 
  side 
  of 
  the 
  new 
  body, 
  and 
  as 
  the 
  

   velocity 
  of 
  each 
  of 
  the 
  two 
  bodies 
  was 
  originally 
  opposite 
  to 
  that 
  of 
  the 
  

   other, 
  rotation 
  is 
  a 
  necessary 
  consequence. 
  

  

  There 
  are 
  two 
  chief 
  reasons 
  for 
  the 
  inequality 
  of 
  the 
  balance 
  of 
  mo- 
  

   mentum 
  at 
  the 
  two 
  sides 
  of 
  the 
  coalesced 
  mass 
  : 
  1st. 
  The 
  piece 
  cut 
  off 
  will 
  

   be 
  much 
  thicker 
  towards 
  the 
  middle 
  of 
  the 
  original 
  mass 
  than 
  at 
  the 
  out- 
  

   side. 
  2nd. 
  The 
  density 
  of 
  the 
  inside 
  is 
  much 
  greater 
  than 
  that 
  of 
  the 
  

   outside, 
  in 
  consequence 
  of 
  the 
  greater 
  pressure, 
  and 
  also 
  from 
  the 
  fact 
  that 
  

   it 
  is 
  probable 
  the 
  heavier 
  elements 
  are 
  towards 
  the 
  centre 
  of 
  the 
  raass. 
  It 
  

   may 
  easily 
  be 
  seen 
  that 
  the 
  resultant 
  momentum 
  on 
  the 
  two 
  opposite 
  sides 
  

   are 
  in 
  opposite 
  directions, 
  consequently 
  tending 
  to 
  rotation, 
  

  

  