REMARKS  ON  THE  COHESION  FIGURES  OF  LIQUIDS.  347 
film.  The  mixtures  were  made  in  a  test-tube  held  in  warm  water, 
and  stirred  with  a  glass  rod. 
Fig.  2  is  a  portion  of  the  figure  of  a  sample  of  croton  oil,  of 
a  brownish-amber  color :  this  opened  into  splendid  rings,  which 
quickly  disappeared,  when  the  film  retreated  upon  itself,  leaving 
a  minute  spray  of  oil.  Another  specimen  which  I  have  had  by 
me  about  two  years,  opened  with  a  fine  display  of  rings,  and  a 
corona  which  formed  a  large  perforated  pattern, cwhen  the  film 
gathered  itself  up,  and  left  a  train  of  oil  behind.  The  figure 
was  like  that  of  the  first,  only  in  the  gathering  up,  the  edge  of 
the  film  was  torn  away.  A  specimen  from  the  Dutch  court  of 
the  International  Exhibition,  probably  from  Java,  flashed  out 
into  a  small  figure  with  iridescent  rings,  and  immediately  re- 
treated upon  itself.  A  fourth,  from  the  India  Museum,  of  a 
light  amber  color,  required  to  be  warmed.  It  formed  a  remark- 
able and  beautiful  figure,  but  the  display  of  the  usual  phenomena 
was  arrested  by  chilling,  a  dull  frosty  silvery  appearance  com- 
ing over  the  figure,  which  though  very  beautiful,  prevented  the 
film  from  telling  its  history.  This  oil  set  and  became  opaque  a 
little  below  50°  F.  A  fifth  specimen  purchased  by  me  seven  or 
eight  years  ago  in  Prussia,  gave  a  very  good  figure. 
Figs.  3  and  4  are  portions  of  the  figures  of  olive  oil.  Fig.  3 
is  from  a  specimen  marked  « extra  sublime,"  Fig,  4  fro  n  a 
specimen  marked  "  Tuscany,  fine."  The  enormous  demand  for 
olive  oil  offers  a  great  temptation  to  the  use  of  cheaper  oils.  In 
this  country  the  oil  of  sessame  seed  is  used  either  instead  of 
olive  oil  or  for  mixing  with  it,  while  in  France  poppy-seed  oil  is 
largely  employed  for  the  purpose.  Figures  of  these  are  given, 
Fig.  5  being  that  of  sessame,  and  Fig.  6  that  of  poppy.*  These 
oils,  together  with  lard  oil,  Fig.  7,  are  also  used  for  mixing  with 
some  of  the  medicinal  oils. 
A  good  deal  of  interest  is  just  now  felt  respecting  linseed  oil. 
I  ha  ve  lately  performed  a  number  of  experiments  with  it,  an 
account  of  which  I  must  reserve  until  the  Journal  can  better 
afford  space  for  such  minute  details. 
-  The  experiments  which  furnished  these  figures  were  performed  in 
winter  in  a  warm  room,  and  the  oils  had  to  be  warmed  befoie  they  could 
be  used. 
