Am.  Jour.  Pliarm.) 
Sept.,  1884.  j 
Precipitates  in  Fluid  Extracts. 
457 
In  carrying  this  series  of  experiments  further,  it  is  readily  shown 
that  not  only  can  we  separate  liquids  from  each  other  within  the  paper, 
but  we  can  separate  them  as  liquids  by  acknowledging  the  fact  that  a 
liquid  tends  to  flow  from  a  tube,  capillary  or  otherwise,  if  the  extremity 
is  beneath  the  surface  of  the  liquid  in  the  container.  Two  test-tubes 
were  placed  beside  each  other,  and  into  one  an  inch  of  Solution  of  ferric 
sulphate  (the  strength  before  named)  was  poured.  A  strip  of  blotting- 
paper  was  then  so  placed  that  one  end  reached  into  the  liquid,  while 
the  other  end  rested  below  it  in  the  other  vial.  The  paper  was  curved 
so  that  the  height  was  four  inches ;  therefore  the  liquid  traversed 
eight  inches.  The  exposed  part  of  the  paper  was  covered  by  means 
of  a  sheet  of  rubber,  in  order  to  retard  evaporation.    (See  Fig.  6.) 
Fig.  V. 
—  A 
3 
"A— - 
0 
AS- 
■A 
ISftffts 
e 
A,  height  of  colorless  liquid.    B,  height  to  which  the  ferrous  sulphate  is  carried.    C,  height 
to  which  the  sulphate  of  copper  is  carried.  D,  height  to  which  the  ferric  sulphate  is  carried. 
In  twenty-four  hours  a  layer  of  colorless  liquid  was  carried  into  the 
empty  vial,  and  this  liquid  refused  to  show  a  trace  of  iron  by  the  usual 
reagents. 
Therefore,  to  sum  up  from  the  view  presented  by  these  experi- 
ments : 
The  solvent  can  be  perfectly  separated  from  dissolved  matter  by  what 
appears  to  be  simply  capillary  attraction. 
