﻿LIMESTONES 
  OF 
  NEW 
  YORK 
  AND 
  THEIR 
  ECONOMIC 
  VALUE 
  377 
  

  

  Slaking. 
  When 
  lime 
  is 
  placed 
  in 
  water 
  the 
  oxid 
  unites 
  with 
  

   the 
  water 
  and 
  hydroxid 
  of 
  , 
  lime 
  is 
  formed. 
  This 
  is 
  accompanied 
  

   by 
  the 
  evolution 
  of 
  heat 
  and 
  an 
  increase 
  in 
  volume. 
  Fat 
  limes 
  

   slake 
  very 
  fast 
  and 
  produce 
  more 
  heat 
  than 
  lean 
  ones. 
  Lime 
  will 
  

   slake 
  even 
  in 
  the 
  air 
  by 
  the 
  absorption 
  of 
  moisture. 
  If 
  not 
  used 
  

   immediately 
  it 
  should 
  therefore 
  be 
  protected 
  from 
  the 
  atmosphere 
  

   as 
  much 
  as 
  possible. 
  

  

  Lime 
  may 
  be 
  slaked 
  by 
  putting 
  the 
  lumps 
  in 
  water 
  for 
  a 
  few 
  

   minutes 
  and 
  then 
  withdrawn 
  and 
  packed 
  away 
  to 
  allow 
  the 
  lime 
  

   to 
  change 
  to 
  powder. 
  The 
  common 
  method 
  usually 
  employed 
  

   in 
  building 
  operations 
  is 
  to 
  mix 
  the 
  lime 
  with 
  water 
  in 
  a 
  box. 
  

   Too 
  much 
  water 
  makes 
  it 
  thin 
  and 
  injures 
  its 
  cohesive 
  strength. 
  

   If 
  the 
  water 
  is 
  added 
  in 
  part 
  and 
  the 
  rest 
  later, 
  the 
  lime 
  becomes 
  

   granular 
  and 
  lumpy. 
  

  

  After 
  slaking 
  sand 
  is 
  added 
  to 
  the 
  lime 
  to 
  make 
  mortar. 
  Ac- 
  

   cording 
  to 
  Gilmore 
  a 
  the 
  lime* 
  forms 
  both 
  silicate, 
  carbonate 
  and 
  

   hydrate, 
  and 
  the 
  crystals 
  of 
  these 
  compounds 
  interlock 
  with 
  the 
  

   sand 
  grains, 
  thus 
  binding 
  the 
  whole 
  together 
  into 
  a 
  solid 
  mass. 
  

   In 
  the 
  course 
  of 
  time 
  all 
  the 
  lime 
  changes 
  to 
  carbonate, 
  but 
  this 
  

   change 
  may 
  take 
  a 
  number 
  of 
  years. 
  

  

  Slaked 
  lime 
  is 
  used 
  for 
  a 
  variety 
  of 
  purposes. 
  Its 
  chief 
  use 
  

   is 
  for 
  mortar. 
  Quicklime 
  is 
  a 
  very 
  strong 
  base; 
  it 
  displaces 
  car- 
  

   bonates 
  of 
  the 
  alkalies 
  and 
  serves 
  therefore 
  for 
  the 
  manufacture 
  

   of 
  caustic 
  of 
  potash 
  and 
  caustic 
  soda. 
  It 
  precipitates 
  magnesia 
  

   from 
  solutions 
  of 
  salts, 
  and 
  has 
  a 
  use 
  in 
  the 
  manufacture 
  of 
  am- 
  

   monia 
  from 
  ammonium 
  chlorid. 
  With 
  chlorin 
  it 
  forme 
  chlorid 
  

   of 
  lime, 
  and 
  with 
  other 
  acids 
  various 
  salts 
  of 
  lime. 
  In 
  the 
  

   manufacture 
  of 
  illuminating 
  gas 
  it 
  serves 
  to 
  purify 
  the 
  gases 
  

   from 
  carbonic 
  acid 
  and 
  hydrogen 
  sulfid. 
  It 
  is 
  used 
  in 
  the 
  

   manufacture 
  of 
  soda 
  and 
  in 
  the 
  extraction 
  of 
  sugar 
  from 
  beet 
  

   juice. 
  In 
  candle 
  manufacture 
  it 
  is 
  used 
  to 
  saponify 
  the 
  fats, 
  in 
  

   tanning 
  to 
  remove 
  the 
  hair 
  from 
  the 
  hides, 
  in 
  bleaching, 
  and 
  in 
  

   dyeing, 
  as 
  a 
  disinfectant; 
  it 
  is 
  also 
  used 
  to 
  treat 
  cryolite 
  in 
  the 
  

   manufacture 
  of 
  alum 
  and 
  in 
  the 
  production 
  of 
  fertilizers. 
  

  

  a 
  On 
  limes, 
  hydraulic 
  cements 
  and 
  mortars, 
  p. 
  299. 
  

  

  