560  NEW  APPARATUS  FOR  CONCENTRATING  SULPHURIC  ACID. 
affect  vegetable  colors,  is  void  of  smell,  and  has  a  sweetish  cool- 
ing taste.  The  result  of  the  elementary  organic  analysis  of 
betain  dried  and  fully  deprived  of  all  water  led  to  the  formula 
C5HnN02 ;  the  crystalline  air-dried  substance  has  the  formula 
C5HijN02  +  H2O.  This  base  yields,  with  many  acids,  beauti- 
fully crystallised  salts,  and  readily  forms  well-crystallised  double 
salts  with  the  chlorides  of  gold  and  platinum,  mercury,  cadmium 
and  zinc.  When  betain  is  boiled  with  an  aqueous  solution  of 
caustic  potassa,  it  is  thereby  split  up  into  several  bases,  am.ong 
which  trimethylamin  is  found.  Oxidation  of  betain  by  means  of 
chromic  acid  and  the  action  of  strong  hydriodic  acid,  both  tried 
in  sealed  tubes,  led  to  no  results  of  any  value.  Betain  resists 
the  oxidising  action  of  chromic  acid. — Chem.  News,  August  27, 
1869,  from  Bericlite  der  Deutscheii  Ohem.  G-esellsch.  zu  Berlin, 
1869. 
NEW  APPARATUS  FOR  THE  CONCENTRATION  OF  SUL- 
PHURIC  ACID. 
By  M.  Cotelle. 
It  is  a  well  known  fact  that  the  concentration  of  sulphuric 
acid  in  platinum  vessels  is  an  expensive  process,  owing  to  the 
high  price  of  the  first  purchase  of  these  apparatus,  and  the  ex- 
pense attending  any  soldering  or  repair.  The  author  has  had 
made  a  column,  lined  inside  with  fire-bricks,  and  made  outside 
of  good  ordinary  bricks  ;  it  rests  on  a  large  pedestal.  This 
column  is  open  at  both  top  and  bottom ;  but  in  these  openings 
are  fitted  fire-clay  stoppers.  The  inside  of  this  apparatus  is 
fitted  with  previously  calcined  pumice-stone  ;  inside  the  lower 
portion  of  this  column,  openings  are  made  between  the  bricks, 
through  which  a  current  of  highly-heated  air  is  forced.  From 
the  top  the  acid,  which  has  to  be  concentrated,  is  made  to  trickle 
on  the  pumice-stone,  and,  meeting  with  a  current  of  highly- 
heated  air,  the  superfluous  water  is  driven  off,  and  the  acid,  on 
arriving  at  the  bottom,  is  in  a  concentrated  state,  and  runs  off 
in  properly-arranged  vessels. — Chem.  News,  August  27,  1869, 
from  Jour,  de  Pharm.  et  de  Chim.,  July,  1869. 
