The  blast  of  air  driven  from
the  rubber  bulb  as  it  passes
over  the  end  of  the  upright
tube,  sweeps  along  the
neighboring  molecules  of  air
and  produces  a  partial  vacuum  in  the  tube.*  The


Atomizer.
*  In  locomotives,  this  principle  of  the  adhesion  of  gases  to  gases  is  ap-
plied to  produce  a  draft.     The  waste  steam  is  thrown  into  the  smoke-pipe,


14.4        PRESSURE     OF     LIQUIDS     AND     GASES.
pressure  of  the  air  in  the  bottle  drives  the  liquid  up
the  tube,  and  at  the  mouth  the  blast  of  air  carries
it  off  in  fine  drops.
The  action  of  a  current  of  air  in  dragging  along
with  it  the  adjacent  still  atmosphere  and  so  tending
to  produce  a  vacuum,  is  shown  by  the  apparatus
represented  in  Fig.  116.  A  globe,  a,  is  connected

FIG.  116.
Tube  for  showing  Adhesion  of  Air.
with  a  horizontal  tube,  c,  containing  colored  water.
