VARIETIES. 
375 
active  remedies  for  consumption.  Dr.  Parola,  the  author,  describes  its 
action  as  infallible,  if  not  in  curing  the  disease,  at  least  in  staying  the 
pulmonary  inflammation  which  constantly  accompanies  the  formation  of 
the  tubercle.  He  administers  thirty-one  grains  of  the  powder  per  day,  and 
suspends  it  every  four  or  five  days  for  forty-eight  hours.  When  the  stomach 
is  too  weak,  the  resinous  extract  may  be  administered  in  pills  instead  of 
the  powder,  to  the  amount  of  one  and  a  quarter  grains,  or  else  a  portion  in 
a  solution  of  gum.  Quinine,  foxglove,  and  even  opium,  may  sometimes 
be  administered  together  with  it.  By  this  treatment  Dr.  Parola  has  cured 
sixteen  cases  out  of  thirty-one  of  alleged  confirmed  consumption  in  an  ad- 
vanced stage. — Scientific  American. 
Sulphurous  Acid. — The  application  of  this  acid  to  manufactures  has  been 
much  impeded  by  the  difficulty  which  the  preparation  of  its  solution  pre- 
sents on  a  large  scale  ;  for  the  production  of  sulphurous  acid,  as  given  in 
books,  is  always  dangerous,  especially  when  its  solution  has  to  be  prepared 
in  large  quantities.  This  difficulty  I  have  overcome  by  a  process  which  T 
here  give  to  the  public,  and  which  enables  me  to  prepare  thousands  of  gal- 
lons per  day  of  a  saturated  solution.  The  process  consists  in  burning 
sulphur  in  a  small  furnace,  and  conducting  the  acid  gas  through  earthen- 
ware tubes,  surrounded  with  water,  so  as  to  cool  them.  It  is  then  made  to 
ascend  through  a  wooden  column,  forty  feet  high,  and  about  four  feet  wide, 
filled  with  pumice-stone  which  has  been  previously  washed  with  muratic  acid, 
and  then  with  water.  Whilst  the  acid  ascends  through  the  porous  pumice- 
stone,  it  meets  a  certain  and  known  quantity  of  water  descending,  which 
dissolves  the  acid.  By  opening,  more  or  less,  a  valve  at  the  top  of  the 
column,  a  more  or  less  rapid  current  is  established.  With  a  little  care,  a 
saturated  solution  runs  out  constantly  from  the  bottom  of  the  column  into 
a  confined  reservoir,  in  which  it  is  stored  for  use  until  required. 
I  was  led  to  contrive  the  above  process  from  a  wish  to  use  sulphurous 
acid  in  sugar  refining,  convinced  that  it  would  be  far  superior  to  the  sul- 
phate of  lime  (which  was  so  strongly  recommended  a  few  years  ago  by  M. 
Dumas  and  M.  Melsens),  because,  that  by  its  volatility  it  would  not  re- 
main in  the  syrups  or  molasses,  and  give  them,  as  the  sulphate  does,  a 
disagreeable  taste,  in  consequence  of  the  lime  of  the  sulphate  remaining  in 
the  syrup  as  acetate  or  lactate.  These  anticipations  were  not  only  realized, 
but  I  also  found  that  sulphurous  acid  possesses  two  advantages  for  the 
sugar  refiner :  First,  that  it  stops  the  fermentation  of  his  hot  liquors  as 
they  come  out  of  the  filters  ;  and  secondly,  when  properly  applied,  it  tends 
to  prevent  the  re-coloration  of  the  liquors  during  their  concentration  in  the 
vacuum  pan.  In  practice'  I  found  that  very  successful  results  were  obtained 
by  adding  two  gallons  of  a  saturated  solution  of  sulphurous  acid  to  every 
one  hundred  gallons  of'decolorized  liquor,  as  it  left  the  char  filter,  and  was 
collected  in  tanks,  until  pumped  up  or  run  into  the  vacuum  pan. — Professor 
F.  Crace  Calvert,  in  Scientific  American. 
