﻿598 
  DR 
  GEORGE 
  WILSON 
  ON 
  NITRIC 
  ACID, 
  &0. 
  

  

  white 
  heat, 
  assisted 
  by 
  platina, 
  — 
  or 
  by 
  chlorine 
  and 
  its 
  congeners, 
  with 
  their 
  affi- 
  

   nities 
  for 
  hydrogen 
  exalted 
  by 
  sunshine 
  ; 
  but 
  nitric 
  acid 
  is 
  the 
  frailest 
  of 
  oxides. 
  

   It 
  not 
  only 
  parts 
  with 
  oxygen 
  to 
  the 
  immense 
  majority 
  of 
  metals, 
  and 
  of 
  metallic 
  

   and 
  organic 
  compounds, 
  but 
  the 
  simple 
  application 
  of 
  heat 
  deoxidises 
  it 
  ; 
  and 
  sun- 
  

   light, 
  which 
  so 
  greatly 
  intensifies 
  the 
  inherent 
  deoxidising 
  power 
  of 
  a 
  plant, 
  can, 
  

   without 
  the 
  co-operation 
  of 
  its 
  complex 
  organic 
  apparatus, 
  compel 
  nitric 
  acid 
  to 
  

   undergo 
  deoxidation. 
  

  

  If, 
  therefore, 
  sunlight 
  alone 
  can 
  deoxidise 
  nitric 
  acid, 
  sunlight, 
  co-operating 
  

   with 
  a 
  powerful 
  deoxidising 
  apparatus, 
  will 
  not 
  be 
  less 
  efficacious 
  ; 
  and 
  those 
  

   chemists 
  who 
  declare 
  that 
  a 
  plant 
  can 
  deoxidise 
  water, 
  carbonic 
  acid, 
  and 
  sul- 
  

   phuric 
  acid, 
  but 
  cannot 
  deoxidise 
  nitric 
  acid, 
  are 
  uttering 
  the 
  paradox, 
  that 
  the 
  

   more 
  easy 
  the 
  decomposition 
  of 
  an 
  oxide 
  is, 
  the 
  more 
  difficult 
  does 
  a 
  plant 
  find 
  it 
  

   to 
  be 
  to 
  decompose 
  it 
  ; 
  so 
  that 
  if 
  it 
  be 
  exceedingly 
  susceptible 
  of 
  deoxidation, 
  then 
  

   the 
  plant, 
  whose 
  greatest 
  chemical 
  power 
  is 
  a 
  deoxidising 
  one, 
  cannot 
  deoxidise 
  it 
  

   at 
  all. 
  

  

  No 
  one, 
  I 
  think, 
  would 
  articulately 
  defend 
  such 
  a 
  doctrine. 
  The 
  opposite 
  con- 
  

   clusion 
  is 
  surely 
  the 
  just 
  one, 
  that 
  if 
  nitric 
  acid 
  be 
  conveyed 
  into 
  plants, 
  it 
  will 
  be 
  

   reduced 
  by 
  loss 
  of 
  oxygen 
  finally 
  to 
  the 
  condition 
  of 
  nitrogen, 
  and 
  as 
  such 
  be 
  

   as 
  available 
  for 
  the 
  production 
  of 
  azotised 
  vegetable 
  compounds 
  as 
  the 
  nitrogen 
  

   of 
  ammonia. 
  

  

  Teachers 
  of 
  chemistry 
  appear 
  to 
  be 
  reluctant 
  to 
  admit 
  two 
  sources 
  of 
  nitrogen 
  

   for 
  plants, 
  because 
  it 
  complicates 
  their 
  statements, 
  and 
  multiplies 
  their 
  formulae 
  ; 
  

   but 
  the 
  partial 
  representations 
  of 
  truth, 
  to 
  which 
  all 
  teachers 
  are 
  compelled, 
  how- 
  

   ever 
  catholic 
  in 
  spirit, 
  can 
  never 
  justify 
  the 
  expression 
  of 
  one-sided 
  views, 
  as 
  the 
  

   counterpart 
  of 
  the 
  multiform 
  unity 
  of 
  Nature. 
  Those, 
  moreover, 
  who 
  have 
  been 
  

   accustomed 
  to 
  trace 
  back 
  all 
  azotised 
  vegetable 
  compounds 
  to 
  ammonia, 
  need 
  

   only 
  postulate 
  that 
  nitric 
  acid 
  having 
  been 
  deoxidised 
  into 
  nitrogen, 
  that 
  element 
  

   unites 
  with 
  hydrogen 
  to 
  form 
  ammonia 
  before 
  any 
  organic 
  compound 
  is 
  developed 
  ; 
  

   and 
  thereafter 
  they 
  may 
  carry 
  out 
  the 
  ammonia 
  theory 
  as 
  before. 
  Such 
  a 
  con- 
  

   version 
  of 
  nitric 
  acid 
  into 
  ammonia 
  is 
  not 
  hypothetical, 
  for 
  it 
  can 
  be 
  readily 
  ef- 
  

   fected 
  by 
  diluting 
  the 
  acid 
  largely 
  with 
  water, 
  and 
  dissolving 
  zinc 
  in 
  it. 
  

  

  It 
  would 
  more 
  consist 
  with 
  the 
  modesty 
  of 
  true 
  science, 
  to 
  be 
  less 
  dogmatic 
  

   than 
  we 
  generally 
  are 
  on 
  the 
  phenomena 
  which 
  occur 
  within 
  the 
  inscrutable 
  re- 
  

   cesses 
  of 
  a 
  living 
  plant 
  ; 
  and 
  to 
  admit 
  the 
  probability 
  of 
  its 
  being 
  able 
  to 
  employ 
  

   as 
  food 
  various 
  azotised, 
  as 
  well 
  as 
  other 
  compounds. 
  If, 
  however, 
  we 
  are 
  re- 
  

   quired 
  to 
  reduce 
  to 
  its 
  simplest 
  chemical 
  expression 
  the 
  conclusion 
  which 
  our 
  

   present 
  science 
  warrants 
  regarding 
  the 
  inorganic 
  origin 
  of 
  the 
  nitrogen 
  so 
  essential 
  

   to 
  plants, 
  we 
  must 
  not 
  say 
  that 
  only 
  ammonia, 
  or 
  only 
  nitric 
  acid, 
  is 
  its 
  source, 
  

   but 
  that 
  both 
  are 
  ; 
  or, 
  in 
  a 
  word, 
  that 
  the 
  chief 
  mineral 
  or 
  inorganic 
  representa- 
  

   tive 
  and 
  parent 
  of 
  the 
  nitrogenous 
  constituents 
  of 
  plants 
  and 
  animals 
  is 
  the 
  Nitrate 
  

   of 
  Ammonia. 
  

  

  