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MODE  OF  PREPARING  THE  CUTCH  OF  COMMERCE. 
rate  of  flow  can  be  checked  or  augmented  at  will,  the  tempera- 
ture is  perfectly  under  the  control  of  the  operator. 
In  the  model  which  has  been  fitted  up  at  Messrs.  Doulton  & 
Watts'  to  illustrate  the  principle  of  this  method  of  working, 
the  pyrometer  generally  indicates  from  600°  to  700°  F.,  while 
a  saturated  solution  of  chloride  of  calcium  is  maintained  at  the 
boiling  point  in  a  shallow  stoneware  pan.  No  smell  of  oil  is 
perceptible  in  the  room ;  and  it  is  stated  that  the  same  oil  may 
be  used  for  years,  without  deterioration  or  causing  any  deposit 
in  the  pipes.  As  contrasted  with  steam  heat,  the  inventor  claims 
for  his  process  a  saving  of  30  per  cent,  in  fuel.  It  is  obvious 
that  the  large  amount  of  heat  necessary  to  convert  water  at  212° 
F.  into  steam  at  212°  is  hereby  economized.  The  stoneware 
used  in  this  process  is  manufactured  expressly  by  Messrs.  Doul- 
ton, to  ensure  its  being  quite  impervious  to  the  oil. 
Other  applications  of  this  method  of  conveying  heat  are 
included  in  Mr.  Coffey's  patent ;  but  its  easy  adaptation  to 
heating  stoneware  will  probably  be  of  the  most  interest  to 
chemists. — Ohem.  News^  June  10,  1870. 
MODE  OF  PREPARING  THE  CUTCH  OF  COMMERCE  FROM 
THE  ACACIA  CATECHU. 
By  Claude  Dumaine. 
Of  this  tree  there  are  two  varieties, — a  white  and  a  red  kind ; 
bat  the  cutch  or  catechu  is  almost  always  prepared  from  the  red 
kind,  the  white  being  seldom  cut  down.  Cutch,  or  catechu,  is 
prepared  thus  :  The  tree  is  cut  down  to  about  6  to  12  inches  from 
the  ground,  and  chopped  into  small  pieces,  the  smaller  branches 
and  bark  being  rejected.  The  chopped  wood  is  then  taken  to 
the  place  of  manufacture,  generally  under  trees  in  the  open  air, 
and  placed  over  a  brisk  fire  in  mud  jars,  called  gharrahs,  filled 
with  about  two-thirds  of  water.  This  is  allowed  to  boil  down 
till,  with  the  extracted  matter,  it  forms  a  liquid  of  syrupy  con- 
sistence. The  contents  of  several  jars  are  then  poured  into  a 
larger  jar  and  again  placed  over  a  brisk  fire  for  a  period  of  from 
two  to  four  hours,  and,  when  sufficiently  boiled  down,  it  is  poured 
out  over  mats  covered  with  ashes  of  cow  dung  and  allowed  to 
dry.  The  wood,  when  dry,  is  used  for  fuel. — Journ.  of  Agr.  and 
Sortie.  Soc.  of  India,  pt.  iv,  p.  399,  1869,  from  Pharm.  Journ. 
July  9,  1870. 
