﻿184 
  True 
  — 
  Toxic 
  Action 
  of 
  Acids 
  and 
  

  

  cant 
  also, 
  likewise 
  the 
  residue 
  of 
  un-ionized 
  molecules, 
  should 
  

  

  dissociation 
  be 
  incomplete. 
  The 
  same 
  general 
  considerations 
  

  

  obtain 
  also 
  for 
  the 
  sodium 
  salts. 
  Since 
  in 
  both 
  acid 
  and 
  salt 
  

  

  the 
  same 
  anions 
  are 
  found, 
  the 
  difference 
  between 
  the 
  death- 
  

  

  . 
  + 
  . 
  

  

  limits 
  of 
  acid 
  and 
  salt 
  measures 
  roughly 
  the 
  action 
  of 
  H. 
  ions, 
  

  

  provided 
  that 
  ionization 
  be 
  found 
  in 
  like 
  degree 
  in 
  both. 
  

   Should 
  it 
  be 
  unlike 
  and 
  incomplete, 
  the 
  toxic 
  action 
  will 
  vary 
  

   according 
  to 
  the 
  number 
  of 
  molecules 
  ionized 
  (1). 
  

  

  Letting 
  t 
  equal 
  the 
  toxic 
  value 
  of 
  any 
  acid 
  or 
  salt, 
  k 
  the 
  par- 
  

   tial-toxicity 
  of 
  the 
  cations, 
  a 
  the 
  partial-toxicity 
  of 
  the 
  anions 
  

   and 
  m 
  the 
  partial-toxicity 
  of 
  the 
  residual 
  undissociated 
  mole- 
  

   cules, 
  then, 
  should 
  ionization 
  be 
  complete, 
  t—Jc+a. 
  Should 
  

   ionization 
  be 
  incomplete, 
  t—k+a+m. 
  In 
  the 
  case 
  of 
  acids, 
  h 
  

  

  would 
  represent 
  the 
  partial-toxicity 
  due 
  to 
  H 
  ions 
  ; 
  in 
  the 
  

  

  sodium 
  salts 
  it 
  would 
  represent 
  the 
  partial-toxicity 
  of 
  the 
  Na 
  

   ions. 
  

  

  In 
  hydrochloric 
  acid 
  we 
  have 
  a 
  type 
  of 
  the 
  stronger 
  inor- 
  

   ganic 
  acids. 
  It 
  dissociates 
  very 
  freely 
  in 
  relatively 
  strong 
  con- 
  

   centrations 
  and 
  gives 
  a 
  valuable 
  standard 
  of 
  comparison 
  by 
  

   which 
  to 
  judge 
  the 
  weaker 
  organic 
  acids. 
  It 
  is 
  practically 
  

   completely 
  ionized 
  at 
  the 
  death-limit 
  characteristic 
  for 
  the 
  

   white 
  lupine, 
  one 
  molecular-weight 
  in 
  grams 
  dissolved 
  in 
  6400 
  

   liters, 
  hence 
  this 
  case 
  illustrates 
  the 
  simpler 
  instance, 
  t=k 
  + 
  a. 
  

  

  The 
  toxic-value 
  of 
  the 
  Ka 
  salt, 
  NaCl, 
  is 
  one 
  gram-molecule 
  

   of 
  the 
  substance 
  dissolved 
  in 
  sixteen 
  liters 
  of 
  water, 
  or 
  briefly, 
  

   16. 
  At 
  this 
  relatively 
  great 
  concentration, 
  this 
  salt 
  is 
  not 
  com- 
  

   pletely 
  dissociated, 
  only 
  about 
  85 
  per 
  cent 
  of 
  the 
  molecules 
  

   being 
  ionized 
  (5). 
  The 
  value 
  16 
  represents, 
  therefore, 
  the 
  sum 
  

  

  + 
  . 
  

  

  of 
  the 
  partial-toxicities 
  of 
  Na 
  ions, 
  CI 
  ions 
  and 
  15 
  per 
  cent 
  of 
  

  

  undissociated 
  molecules. 
  Here, 
  t=k 
  + 
  a+m. 
  

  

  We 
  may 
  obtain 
  an 
  approximate 
  idea 
  of 
  the 
  actual 
  value 
  of 
  

  

  H 
  ions 
  by 
  a 
  comparison 
  of 
  the 
  toxicity 
  of 
  HC1 
  with 
  that 
  of 
  

   NaCl. 
  As 
  appears 
  from 
  data 
  just 
  given, 
  it 
  seems 
  to 
  lie 
  near 
  

   6400. 
  Strong 
  corroborative 
  evidence 
  may 
  be 
  obtained 
  by 
  a 
  

   study 
  of 
  sulphuric 
  acid 
  and 
  some 
  of 
  its 
  compounds. 
  This 
  

   acid 
  is 
  practically 
  entirely 
  ionized 
  (6) 
  at 
  the 
  death-limit 
  for 
  

  

  lupines, 
  12,800, 
  and 
  since 
  it 
  splits 
  off 
  two 
  H 
  ions 
  from 
  every 
  

   molecule, 
  it 
  w 
  T 
  ould 
  have, 
  in 
  chemically 
  equivalent 
  quantities, 
  

  

  twice 
  the 
  number 
  of 
  H 
  ions 
  found 
  in 
  HC1, 
  and 
  should 
  have 
  

   its 
  death-limit 
  at 
  one-half 
  the 
  concentration 
  of 
  the 
  mono-basic 
  

   acid. 
  This 
  has 
  been 
  realized 
  by 
  experiment 
  (1). 
  Should 
  one 
  

   of 
  the 
  H 
  atoms 
  of 
  H 
  2 
  S0 
  4 
  be 
  replaced 
  by 
  some 
  relatively 
  harm- 
  

   less 
  metal, 
  the 
  death-limit 
  should 
  lie 
  at 
  approximately 
  the 
  same 
  

  

  