i88 
Liquefaction  of  Gases. 
f  Am.  Jour.  Pharm. 
(       April,  1878. 
gauges  N  and  N'.  a  contains  the  mercury  reservoir,  into  which  is 
plunged  the  glass  tube  filled  with  gas.  This  part  of  the  arrangement 
is  shown  in  Fig.  4,  which  is  half  size. 
Fig.  4.  Fig.  5. 
Fig.  5  represents  the  same  portion  of  the  apparatus  supported  on  a 
tripod,  P,  for. use  in  lecture  experiments  in  connection  with  any  power- 
ful force-pump.  E  is  a  hollow  nut  for  connecting  the  pipe  U,  and  N 
is  a  plug  for  closing  the  orifice  in  R  when  the  reservoir  a  is  being  filled 
with  mercury.  After  introducing  the  open  end  of  the  gas  tube,  T,  into 
the  mercury  the  other  parts  of  the  apparatus  are  placed  in  position,  as 
