136 
MANUFACTURE  OF  AMMONIA,  ETC. 
nia  through  the  apparatus,  care  being  taken  to  use  them  so  dilute* 
that  the  vapor,  which  escapes  with  them,  shall  be  sufficient  in 
quantity  to  prevent  the  solidification  of  the  ammonia,  by  the  car- 
bonic acid  which  rises  with  it,  and  the  consequent  obstruction  of 
the  passages.  Instead  of  being  furnished  with  perforations,  valves, 
and  pipes,  the  diaphragms  may  have  plain  surfaces,  and  each  be 
bent  upwards  at  one  of  its  sides,  so  as  not  entirely  to  separate  the 
contiguous  chambers.  The  diaphragms  should  be  bent  upwards  at 
opposite  sides  alternately,  thereby  permitting  the  descending  fluid 
to  fall  as  a  cascade  from  the  right  hand  side  of  one  diaphragm  on 
to  the  next  below  ;  and  then  from  the  left  hand  side  of  that  one  on 
to  the  next  in  succession,  and  so  on  until  the  whole  of  the  dia- 
phragms are  occupied  with  liquid.  Tn  this  case  the  liquid  will  be 
heated  by  the  contact  of  the  ascending  steam  sweeping  over  its  ex- 
tensive surface  ;  and  also  by  the  steam  acting  on  the  under  sides 
of  the  diaphragms  on  which  the  liquid  rests. 
Mr.  Philippi's  process  for  obtaining  ammoniacal  salts,  as  pa- 
tented by  him,  July  21,  1842,  is  that  of  decomposing  the  ammo- 
niacal water  of  the  gas-works  by  means  of  sulphate  or  chloride  of 
manganese,  the  gas  being  passed  through  the  solutions  contained 
in  suitable  cisterns  or  apparatus.  Mr.  Philippi  also  describes  an 
arrangement  of  apparatus  suitable  for  obtaining  ammonia  and  am- 
moniacal salts  from  gas  liquor.  For  this  purpose  the  gas  liquor  is 
acted  upon  by  lime  in  a  common  distilling  apparatus,  heated  either 
by  steam  or  otherwise,  by  means  of  a  worm  or  injection  ;  the  am- 
monia set  at  liberty  by  the  heat  escapes  into  a  second  boiler  simi- 
lar to  the  first  one  through  a  connecting  pipe — the  condensing  of 
the  ammoniacal  vapors  heats  the  second  boiler,  in  which  there  are 
lime  and  ammoniacal  waters.  A  third  boiler  is  employed  with  the 
same  effect,  after  which  there  is  a  leaden  worm,  in  which  the  va- 
pors circulate.  This  worm  is  surrounded  by  cold  ammoniacal 
water,  and  descends  into  a  leaden  vessel,  in  which  is  deposited  a 
solution  of  alkali,  which  at  first  is  very  strong,  but  becomes  weaker 
as  the  distillation  goes  on.  The  alkali  is  withdrawn  before  it  de- 
scends below  220°,  but  as  a  part  of  the  ammonia  is  in  a  gaseous 
state,  there  are  two  other  vessels  prepared  after  the  first  one,  the 
whole  forming  a  Woulfe's  apparatus.  The  solution  of  lime  of  the 
second  vessel,  which  is  not  saturated  after  one  distillation,  is  put 
into  the  second  boiler,  that  the  lime  and  ammonia  which  are  dis- 
