130 
MANUFACTURE  OF  AMMONIA,  ETC. 
ously  in  use.  For  this  purpose,  the  patentees  submit  the  ammo- 
niacal  liquor  to  the  action  of  lime,  in  the  following  manner: — To 
every  500  gallons  of  the  liquor  they  add  250  lbs.  of  quicklime, 
slacked  with  a  sufficient  quantity  of  water.  This  is  poured  on  to 
a  grating,  which  is  employed  for  the  purpose  of  preventing  large 
pieces  from  passing  through,  and  is  kept  well  agitated.  It  is  then 
placed  in  a  still,  in  which  it  is  heated  to  from  170°  to  200°  Fahr. 
The  ammonia  thus  becomes  evolved,  and  is  thence  passed  into  acid 
by  which  salts  are  formed,  which  are  obtained  in  solution.  When 
the  ammonia  is  worked  off,  the  residuum  is  cleared  out  and  a  fresh 
charge  put  in.  Mr.  William  Watson  took  out  a  patent,  November 
8,  1838,  for  improvements  in  the  manufacture  of  liquid  ammonia 
applicable  to  the  purposes  of  dyeing,  scouring,  and  other  manufac- 
turing processes.  "  In  this  process,"  states  the  patentee,  "  which 
I  have  invented,  I  manufacture  the  liquid  ammonia  from  gas-water, 
and  I  dispense  entirely  with  the  use  of  sulphuric  or  muriatic  acid, 
and  of  course  with  the  evaporation  and  crystallization.  I  make  it 
in  the  following  manner  : — The  gas-liquor,  or  gas-water,  I  put  in- 
to a  retort  or  any  other  suitable  vessel,  along  with  fresh  slaked 
lime,  the  quantity  of  which  is  to  be  determined  by  the  quality  of 
the  water;  by  the  application  of  heat,  a  tolerably  pure  liquid  am- 
monia is  disengaged,  which,  being  passed  into  water,  forms  a  so- 
lution of  ammonia.  When  this  distillation  has  been  carried  so 
far  that  a  considerable  portion  of  steam  or  the  vapor  of  water 
proceeds  from  the  retort  along  with  the  ammonia,  the  ammoniacal 
solution,  already  formed,  is  to  be  removed — this  I  call  the  first 
portion  ;  and  what  is  collected  afterwards  by  a  continuation  of  the 
process,  I  call  the  second  portion  ;  and,  being  very  impure,  it  is 
put  back  into  the  retort  with  the  mixed  charge  of  gas- water.  The 
first  portion  must  be  again  submitted  to  distillation,  with  or  with- 
out a  small  quantity  of  lime,  and  the  same  precaution  must  be  ob- 
served as  before,  that  is,  so  long  as  the  principal  part  of  what  pro- 
ceeds from  the  retort  or  boilers  is  ammoniacal  gas,  it  must  be 
passed  into  water;  and  when  this  ceases  to  be  the  case,  as  by  con- 
tinuing the  heat  the  water  as  well  as  the  ammonia  will  evaporate, 
the  solution  of  ammonia  already  formed,  must  be  removed.  This 
may  be  called  the  first  portion  of  the  second  distillation.  The  pro- 
cess may  be  continued  then  until  all  or  nearly  all  of  the  ammo- 
nia is  distilled  ;  this  second  portion  is  to  be  returned  as  before  to 
