﻿76 
  Scientific 
  Intelligence. 
  

  

  coloration 
  observable 
  in 
  the 
  green 
  tint 
  of 
  the 
  peas. 
  This 
  practi- 
  

   cally 
  disposed 
  of 
  the 
  only 
  anxiety 
  which 
  Professor 
  Dewar 
  felt 
  

   as 
  to 
  the 
  success 
  of 
  the 
  experiment, 
  and 
  expressed 
  to 
  me 
  on 
  July 
  

   25:— 
  

  

  'My 
  own 
  impression 
  is 
  that 
  unless 
  the 
  sudden 
  vacuum 
  caused 
  

   by 
  the 
  liquid 
  hydrogen 
  cooling 
  has 
  produced 
  physical 
  rupture 
  of 
  

   the 
  seeds, 
  they 
  will 
  germinate 
  as 
  usual. 
  If 
  they 
  survive 
  this 
  

   awful 
  strain, 
  then 
  I 
  believe 
  no 
  increase 
  of 
  the 
  time 
  of 
  cooling 
  

   could 
  produce 
  any 
  effect 
  other 
  than 
  results 
  from 
  one 
  hour's 
  expos- 
  

   ure 
  to 
  such 
  severe 
  cold.' 
  

  

  The 
  seeds 
  were 
  sown 
  in 
  a 
  cool 
  greenhouse, 
  without 
  heat, 
  on 
  

   July 
  21. 
  On 
  August 
  1 
  they 
  had 
  all 
  germinated. 
  In 
  the 
  case 
  of 
  

   the 
  mustard, 
  136 
  young 
  plants 
  were 
  produced 
  from 
  155 
  seeds; 
  

   the 
  remainder 
  had, 
  however, 
  germinated, 
  but 
  the 
  seedlings 
  had 
  

   damped 
  off. 
  One 
  of 
  the 
  packets 
  of 
  wheat, 
  for 
  some 
  reason, 
  

   germinated 
  slightly 
  more 
  slowly 
  than 
  the 
  rest. 
  

  

  On 
  August 
  5, 
  I 
  received 
  a 
  further 
  packet 
  of 
  the 
  seeds 
  (the 
  

   musk 
  excepted, 
  indiscriminately 
  mixed. 
  Professor 
  Dewar 
  wrote 
  

   the 
  same 
  date 
  : 
  — 
  ' 
  I 
  have 
  sent 
  you 
  seeds 
  to-day 
  which, 
  if 
  the 
  

   treatment 
  with 
  cold 
  can 
  kill, 
  ought 
  to 
  be 
  dead. 
  They 
  have 
  been 
  

   immersed 
  in 
  liquid 
  hydrogen 
  for 
  upwards 
  of 
  six 
  hours, 
  and 
  no 
  

   attempt 
  was 
  made 
  to 
  graduate 
  the 
  cooling. 
  They 
  were 
  placed 
  

   in 
  the 
  vacuum 
  vessel 
  into 
  which 
  the 
  liquid 
  hydrogen 
  could 
  drop 
  

   from 
  the 
  apparatus, 
  and 
  had 
  to 
  take 
  their 
  chance. 
  The 
  seeds 
  

   have 
  been 
  soaked 
  in 
  liquid 
  hydrogen, 
  and 
  in 
  this 
  respect 
  differ 
  

   from 
  the 
  last 
  that 
  were 
  cooled 
  in 
  a 
  vacuum 
  from 
  being 
  sealed 
  in 
  

   a 
  glass 
  tube.' 
  

  

  In 
  this 
  instance 
  again 
  the 
  seeds 
  did 
  not 
  show 
  the 
  smallest 
  visi- 
  

   ble 
  trace 
  of 
  the 
  ordeal 
  to 
  which 
  they 
  had 
  been 
  subjected. 
  They 
  

   were 
  sorted 
  out 
  and 
  immediately 
  sown, 
  under 
  the 
  same 
  conditions 
  

   as 
  before. 
  By 
  August 
  9 
  the 
  seeds 
  had 
  all 
  germinated 
  without 
  

   exception. 
  1 
  communicated 
  the 
  result 
  to 
  Professor 
  Dewar, 
  and 
  

   he 
  informed 
  me, 
  August 
  15: 
  — 
  'The 
  temperature 
  Fahrenheit 
  to 
  

   which 
  the 
  seeds 
  were 
  cooled 
  was 
  — 
  453 
  9 
  F. 
  below 
  melting 
  ice.' 
  

  

  These 
  are 
  the 
  details 
  of 
  the 
  experimeut. 
  As 
  it 
  is 
  not 
  likely 
  to 
  

   be 
  often 
  repeated, 
  I 
  have 
  thought 
  it 
  worth 
  while 
  to 
  place 
  them 
  

   on 
  record 
  as 
  precisely 
  as 
  possible. 
  

  

  The 
  first 
  question 
  that 
  suggests 
  itself 
  is, 
  what 
  evidence 
  we 
  have 
  

   for 
  believing 
  that 
  the 
  seeds 
  have 
  actually 
  been 
  brought 
  to 
  the 
  

   almost 
  inconceivable 
  temperature 
  with 
  which 
  they 
  were 
  sur- 
  

   rounded. 
  That 
  they 
  were 
  so 
  brought, 
  Professor 
  Dewar 
  himself 
  

   has 
  not 
  a 
  shadow 
  of 
  doubt. 
  That 
  substances 
  at 
  widely 
  extreme 
  

   temperatures 
  can 
  remain 
  in 
  juxtaposition 
  at 
  least 
  for 
  some 
  time, 
  

   and 
  still 
  maintain 
  them, 
  is 
  illustrated 
  by 
  a 
  striking 
  experiment 
  

   shown 
  by 
  Professor 
  Dewar 
  at 
  the 
  Royal 
  Institution 
  on 
  April 
  1, 
  

   1898. 
  Liquid 
  air 
  poured 
  into 
  a 
  large 
  silver 
  basin 
  heated 
  to 
  red- 
  

   ness 
  remained 
  apparently 
  as 
  quiescent 
  at 
  this 
  high 
  temperature 
  

   as 
  in 
  cooler 
  vessels, 
  and 
  maintained 
  a 
  spheroidal 
  condition. 
  This 
  

   is 
  well 
  understood. 
  But 
  the 
  fact 
  remains 
  that 
  liquid 
  air 
  with 
  a 
  

   temperature 
  of 
  about 
  —190° 
  C. 
  was 
  contained 
  in 
  a 
  vessel 
  which 
  

  

  