﻿594 
  DR 
  GEORGE 
  WILSON 
  ON 
  NITRIC 
  ACID 
  

  

  this 
  point 
  I 
  do 
  not 
  dwell 
  ; 
  for 
  I 
  am 
  content 
  with 
  the 
  alternative 
  conclusion, 
  that 
  

   the 
  nitric 
  acid 
  of 
  thunder-storms 
  either 
  descends 
  at 
  once 
  to 
  the 
  earth, 
  and 
  feeds 
  

   the 
  most 
  luxuriant 
  vegetation 
  known 
  to 
  us 
  ; 
  or 
  that 
  it 
  is 
  diffused 
  through 
  the 
  en- 
  

   tire 
  atmosphere, 
  and 
  is 
  available 
  for 
  the 
  nutrition 
  of 
  the 
  plants 
  of 
  all 
  lands. 
  

  

  Thirdly, 
  Rain-water 
  is 
  often 
  found 
  to 
  contain 
  nitric 
  acid 
  in 
  combination 
  with 
  

   different 
  bases. 
  The 
  most 
  recent 
  observations 
  on 
  this 
  point 
  with 
  which 
  I 
  am 
  

   acquainted, 
  are 
  those 
  of 
  M. 
  Barral, 
  communicated 
  to 
  the 
  French 
  Academy, 
  and 
  

   approved 
  by 
  a 
  committee 
  of 
  that 
  body. 
  If 
  Barral's 
  results 
  are 
  confirmed, 
  and 
  

   are 
  not 
  found 
  to 
  be 
  exceptional, 
  they 
  will 
  compel 
  us 
  to 
  acknowledge 
  a 
  much 
  

   larger 
  proportion 
  of 
  nitric 
  acid, 
  as 
  normally 
  present 
  in 
  the 
  atmosphere, 
  than 
  is 
  

   generally 
  imagined. 
  His 
  researches 
  were 
  made 
  on 
  the 
  water 
  collected 
  in 
  the 
  

   rain-gauges 
  of 
  the 
  Observatory 
  of 
  Paris 
  in 
  1851 
  and 
  1852. 
  

  

  The 
  following 
  are 
  his 
  general 
  conclusions 
  : 
  — 
  

  

  " 
  1°. 
  During 
  one 
  year, 
  reckoning 
  from 
  July 
  1, 
  1851, 
  to 
  June 
  30, 
  1852, 
  there 
  

   fell 
  at 
  Paris 
  a 
  quantity 
  of 
  nitrogen 
  in 
  combination, 
  equal 
  to 
  20*04 
  lbs. 
  avoirdu- 
  

   pois 
  to 
  the 
  English 
  imperial 
  acre 
  ; 
  namely, 
  11-13 
  lbs. 
  in 
  the 
  condition 
  of 
  nitric 
  acid, 
  

   and 
  8*91 
  lbs. 
  in 
  the 
  condition 
  of 
  ammonia.* 
  

  

  " 
  2°. 
  The 
  quantity 
  of 
  ammonia 
  which 
  fell 
  during 
  that 
  period 
  amounted 
  to 
  

   12-29 
  lbs. 
  to 
  the 
  acre. 
  

  

  " 
  3°. 
  The 
  quantity 
  of 
  anhydrous 
  nitric 
  acid 
  which 
  fell 
  during 
  the 
  same 
  period 
  

   amounted 
  to 
  41*24 
  lbs. 
  to 
  the 
  acre. 
  

  

  " 
  4°. 
  The 
  quantity 
  of 
  ammonia 
  diminished 
  in 
  the 
  months 
  during 
  which 
  the 
  

   quantity 
  of 
  nitric 
  acid 
  increased. 
  

  

  " 
  5°. 
  The 
  quantity 
  of 
  nitric 
  acid 
  increased 
  whenever 
  the 
  weather 
  became 
  

   stormy. 
  

  

  "6°. 
  During 
  the 
  months 
  only 
  of 
  February, 
  March, 
  April, 
  and 
  June, 
  the 
  quantity 
  

   of 
  nitrogen 
  in 
  the 
  form 
  of 
  nitric 
  acid, 
  was 
  a 
  little 
  less 
  than 
  the 
  quantity 
  of 
  nitrogen 
  

   in 
  the 
  form 
  of 
  ammonia.''! 
  

  

  These 
  observations 
  apply 
  to 
  rain-water 
  collected 
  in 
  the 
  neighbourhood 
  of 
  a 
  

   great 
  city, 
  and 
  do 
  not 
  admit 
  of 
  direct 
  comparison 
  with 
  the 
  purer 
  rain-water 
  of 
  

   the 
  open 
  country 
  ; 
  but 
  they 
  are 
  very 
  remarkable, 
  not 
  merely 
  as 
  shewing 
  that 
  

   rain 
  brings 
  down 
  nitric 
  acid 
  as 
  well 
  as 
  ammonia, 
  but 
  that, 
  in 
  certain 
  places 
  at 
  

   least, 
  it 
  contains 
  more 
  nitric 
  acid 
  than 
  ammonia. 
  And 
  although 
  a 
  given 
  weight 
  

   of 
  ammonia 
  contains 
  three 
  times 
  the 
  amount 
  of 
  nitrogen 
  which 
  the 
  same 
  weight 
  

  

  * 
  There 
  is 
  some 
  mistake 
  in 
  Barral's 
  numbers, 
  for 
  the 
  statements 
  in 
  the 
  first 
  paragraph 
  do 
  not 
  

   agree 
  with 
  those 
  in 
  the 
  second 
  and 
  third 
  ; 
  as 
  the 
  numbers, 
  however, 
  for 
  nitrogen 
  are 
  calculated 
  from 
  

   the 
  observed 
  quantities 
  of 
  nitric 
  acid 
  and 
  ammonia, 
  the 
  figures 
  representing 
  these 
  are 
  assumed 
  as 
  

   the 
  correct 
  ones. 
  

  

  If 
  so, 
  the 
  quantity 
  of 
  " 
  nitrogen 
  in 
  combination" 
  is 
  equal 
  to 
  20-81 
  lbs. 
  per 
  acre; 
  that 
  of 
  the 
  

   nitrogen 
  in 
  nitric 
  acid 
  is 
  10*69 
  lbs.; 
  and 
  that 
  of 
  the 
  nitrogen 
  in 
  ammonia, 
  10"12 
  lbs. 
  These, 
  ac- 
  

   cordingly, 
  are 
  the 
  numbers 
  which 
  should 
  appear 
  in 
  the 
  first 
  paragraph 
  of 
  Barral's 
  conclusions. 
  

  

  ■*■ 
  Comptes 
  Reudus 
  pour 
  27 
  Septembre 
  1852, 
  p. 
  431. 
  

  

  