THE  PARIS  EXPOSITION. 
Ill 
The  alkali  manufacture,  for  which  England  and  Scotland  are  so  justly 
celebrated,  was  not  so  well  represented  as  it  deserved  to  be.  Those  who 
took  part  were  Messrs.  AUhusen  &  Co.,  the  Walker  Alkali  Co.,  of  New 
Castle-on-Tyne,  Chance  &  Sons,  of  Birmingham,  well  known  in  this 
country  for  the  good  quality  of  their  bicarbonate  of  soda  ;  Muspratt  &  Co., 
of  Liverpool,  the  Jarrow  Company  of  South  Shields,  and  W.  Gossage 
&  Son,  Widnas,  near  Warrington,  Soap  Manufacturers.  The  latter  house 
has  adopted  a  process  analogous  to  that  of  R.  A.  Tilghman's  patent,  by 
which  they  produce  silicate  of  soda  and  other  alkali  products.  The 
general  feature  of  this  process  is  to  cause  the  mixed  vapors  of  chloride  of 
sodium  and  water  to  traverse  an  immense  column  50  feet  high  and  8  feet  in 
diameter  internally,  filled  with  flints  and  sand  balls  previously  heated  in- 
tensely by  several  gas  furnaces  constructed  on  Sieman's  principle,  at  the 
base  of  the  column,  which  is  strongly  built  and  lined  with  the  best  fire 
brick.  The  reaction  results  in  the  elimination  of  chlorine  with  the 
hydrogen  of  the  water  as  hydrochloric  acid,  which  passes  off,  and  may 
be  collected  whilst  the  sodium  taking  its  oxygen  becoming  soda  seizes 
upon  the  silica  of  the  flints,  and  as  fused  silicate  of  soda  flows  downward 
and  is  collected  below.  From  this  compound  by  the  help  of  carbonic 
acid  or  lime  the  various  soda  products  are  made,  and  silica  or  silicate  of 
lime,  as  the  case  may  be,  obtained  as  a  valuable  bye  product.  The  practi- 
cal points  of  difference  bdtween  this  method  and  Tilghman's,  is  in  pre- 
senting the  chloride  of  sodium  in  the  state  of  vapor  mixed  with  its  de- 
composing agent  steam,  instead  of  incorporating  it  with  alumina,  and  in 
the  use  of  the  silica  as  flint,  which  being  attacked  only  on  the  surface, 
the  removal  of  the  resulting  silicate  in  a  liquid  fused  state  is  favored  by  its 
own  gravity.  Whether  this  and  analogous  processes  will  replace  that  of 
Leblanc  in  the  great  alkali  works  of  Europe,  remains  to  be  seen.  It 
was  our  good  fortune,  on  calling  at  the  St.  Rollex  Works,  near  Glasgow, 
in  August,  1867,  to  be  admitted,  and  to  be  conducted  through  the  works 
by  a  young  man  connected  with  the  establishment,  for  whose  polite 
attention  in  explaining  the  various  leading  processes  then  in  operation, 
we  have  always  felt  grateful.  The  great  magnitude  of  the  operations 
here  conducted  is  the  first  most  impressive  feature  that  strikes  the 
visitor,  and  in  keeping  with  this  the  vast  chimney  stack,  until  recently 
the  highest  in  the  world,  elevates  its  smoke  evolving  summit  460  feet  above 
its  base.  (Within  a  few  years  past  a  yet  higher  chimney  has  risen  on  the 
north  side  of  Glasgow).  The  kinds  of  manufacturing  performed  at  these 
works  are  those  which  arise  out  of  the  alkali  production  which  is  the 
great  central  industry ;  for  this  the  sulphur  and  pyrites  of  Italy  and 
Spain  and  the  alkaline  nitrates  of  India  and  South  America  are  used  in 
generating  thousands  of  tons  of  oil  of  vitroil,  which  in  its  turn  is  made 
to  act  on  prodigious  quantities  of  common  salt,  forming  the  crude  sul- 
phate of  soda  needed  in  an  annual  product  of  40,000,000  lbs.  of  alkali. 
But  in  making  this  sulphate  of  soda  immeasurable  volumes  of  muriatic 
