I 
griffin's  reverberatory  gas  furnace. 
533 
would  give  in  a  hundred  parts  carbonate  of  potash  83'676, 
water  16'324.  As,  however,  the  water  expelled  above  100*^  was 
only  10-814,  the  author  decides  that  the  salt  was  KO,CO^HO 
and  the  excess  of  water  hygroscopic  moisture.  When  exposed 
to  the  air  this  salt  quickly  attracts  4-5  more  water,  and  then 
has  the  formula  2(K0  C0.2)3HO.  By  taking  up  a  very  small 
quantity  more  water  the  salt  liquefies  to  an  oily  fluid. — Lo7idon 
Ohem.  News,  June  22,  1861. 
GRIFFIN^S  REVERBERATORY  GAS  FURNACE, 
For  Analytical  Operations  with  Platinum  Crucibles. 
This  apparatus  produces  a  high  temperature  without  the  use 
of  a  blowing-machine.  It  is  especially  suitablefor  the  decom- 
position of  silicious  minerals  by  fusion  with  alkaline  carbonates 
in  platinum  crucibles,  being  capable  of  fusing  1000  grains  of 
anhydrous  carbonate  of  soda  in  ten  minutes. 
The  furnace  is  represent- 
ed by  the  annexed  engrav- 
ing. It  consists  essentially 
of  a  combination  of  tubes, 
within  which  a  mixture  of 
coal  gas  and  air  is  burnt, 
and  in  which  a  small  fire-clay 
or  plumbago  furnace  holds 
the  crucible  in  the  point  of 
greatest  heat. 
Letter  a  represents  a  brass 
tube  and  stop-cock  of  J  inch 
bore,  for  the  supply  of  coal- 
gas  at  ordinary  pressure. 
The  end  of  it,  fixed  within 
the  tube  5,  is  pierced  with 
several  small  holes  for  the 
emission  of  the  gas.  The 
brass  tube  5  is  9  inches  long 
and  1  inch  bore,  open  at  both 
ends.  The  iron  tube  c  is  8 
inches  long  and  2i  inches  diameter,  open  at  both  ends,  but 
