﻿in 
  Their 
  Thermodynamic 
  Relations. 
  169 
  

  

  How 
  differently 
  a 
  thread 
  of 
  paraffin 
  e 
  behaves 
  in 
  a 
  like 
  tube 
  

   at 
  20° 
  and 
  under 
  the 
  same 
  conditions, 
  is 
  seen 
  in 
  the 
  attached 
  

   curve 
  of 
  the 
  chart. 
  Volume 
  is 
  here 
  a 
  slightly 
  increasing 
  

   quantity 
  in 
  the 
  lapse 
  of 
  time, 
  a 
  result 
  doubtless 
  due 
  to 
  

   gradually 
  increasing 
  temperature 
  of 
  the 
  vapor 
  bath. 
  The 
  two 
  

   phenomena 
  are 
  totally 
  dissimilar. 
  So 
  also- 
  as 
  I 
  showed 
  else- 
  

   where, 
  the 
  errors 
  of 
  measurement 
  introduced 
  by 
  the 
  elasticity 
  

   and 
  the 
  viscosity 
  of 
  the 
  glass 
  tube 
  are 
  of 
  insignificant 
  values 
  as 
  

   compared 
  with 
  the 
  enormous 
  compressibilities 
  of 
  the 
  present 
  

   investigation. 
  

  

  To 
  what 
  degree 
  the 
  compressibilities 
  are 
  real 
  may 
  be 
  tested 
  

   during 
  the 
  slower 
  of 
  the 
  above 
  reactions, 
  at 
  185°, 
  when 
  the 
  

   liquid 
  is 
  elastic. 
  The 
  compressibilities 
  per 
  atm. 
  in 
  millionths 
  

   of 
  the 
  normal 
  volume 
  at 
  the 
  outset 
  of 
  the 
  experiment 
  were 
  

  

  20 
  to 
  100 
  atm. 
  100 
  to 
  200 
  atm. 
  200 
  to 
  300 
  atm. 
  300 
  to 
  400 
  atm. 
  

  

  146 
  144 
  142 
  146 
  

  

  and 
  15 
  minutes 
  later 
  

  

  188 
  176 
  201 
  189 
  

  

  the 
  observations 
  being 
  throughout 
  reliable. 
  

  

  At 
  210° 
  the 
  rate 
  of 
  reaction 
  is 
  far 
  too 
  rapid 
  to 
  yield 
  results 
  

   of 
  anything 
  like 
  this 
  degree 
  of 
  precision. 
  A 
  conception 
  of 
  the 
  

   remarkably 
  large 
  results 
  obtained 
  may 
  be 
  secured 
  by 
  recalling 
  

   that 
  water 
  and 
  glass 
  with 
  compressibilities 
  of 
  about 
  100/10 
  6 
  

   and 
  3/1 
  6 
  at 
  210°, 
  during 
  the 
  process 
  of 
  reaction 
  show 
  values 
  

   which 
  can 
  only 
  be 
  compared 
  with 
  so 
  mobile 
  a 
  body 
  as 
  liquid 
  

   ether, 
  between 
  100 
  and 
  200 
  atm. 
  Compressing 
  ether 
  to 
  keep 
  

   it 
  liquid 
  the 
  approximate 
  data 
  for 
  compressibility 
  are 
  

   29° 
  65° 
  100° 
  185° 
  

  

  156 
  207 
  305 
  ' 
  741 
  

  

  millionths 
  per 
  atm., 
  of 
  which 
  the 
  two 
  last 
  values 
  only 
  are 
  large 
  

   enough 
  to 
  compare 
  with 
  the 
  data 
  for 
  water 
  glass. 
  Yet 
  the 
  

   latter 
  solidifies 
  at 
  ordinary 
  temperatures 
  to 
  a 
  hard 
  solid, 
  quite 
  

   glassy 
  in 
  character. 
  

  

  8. 
  The 
  clear 
  coagulum 
  obtained 
  after 
  the 
  reaction 
  has 
  sub- 
  

   sided 
  is 
  again 
  elastic, 
  but 
  its 
  compressibility 
  of 
  minimum 
  value 
  

   probably 
  less 
  than 
  that 
  of 
  water 
  at 
  210°. 
  Compression 
  is 
  

   accompanied 
  with 
  evidences 
  of 
  rigidity 
  and 
  the 
  density 
  of 
  the 
  

   system 
  is 
  a 
  maximum. 
  Currents 
  have 
  ceased. 
  On 
  cooling, 
  

   bubbles 
  appear 
  in 
  the 
  clear 
  column 
  of 
  water 
  glass, 
  originating 
  

   at 
  points 
  in 
  the 
  axis, 
  and 
  growing 
  thence 
  centrifugally 
  outward. 
  

   The 
  volumes 
  in 
  which 
  the 
  mercury 
  globules 
  were 
  snugly 
  

   imbedded 
  at 
  210° 
  now 
  increase, 
  until 
  the 
  cavity 
  is 
  but 
  partially 
  

   filled. 
  As 
  much 
  as 
  J 
  of 
  an 
  ovoid 
  cavity 
  may 
  be 
  empty. 
  All 
  

   of 
  this 
  points 
  to 
  marked 
  contraction 
  on 
  solidification 
  and 
  cool- 
  

   ing. 
  The 
  old 
  capillaries, 
  however 
  carefully 
  protected 
  or 
  slowly 
  

   cooled, 
  invariably 
  break 
  throughout 
  their 
  length 
  in 
  the 
  lapse 
  

  

  