446 
Camphor  Motions. 
f  Am,  Jour.  Pharm. 
t       Sept.,  1885. 
plate  of  an  electrophorus  to  the  water  in  the  dish,  as  described,  not  the 
least  tremor  can  be  perceived.  As  these  results  were  obtained  over 
and  over  again,  there  cannot  be  any  doubt  as  to  the  difference  of  the 
effects  in  the  two  modes  of  operating. 
The  conclusion  that  may  be  drawn  is  that  camphor  motions  are  not 
caused  by  electricity.  In  the  case  of  an  electrified  rod,  dipped  suc- 
cessively in  water,  I  am  inclined  to  the  opinion  that  electricity  acts  in- 
directly by  removing  physical  impurities  from  the  surface  of  the  water, 
as  shown  by  the  following  experiment : 
Take  a  glass  of  water,  and  on  its  surface  place  a  few  pieces  of 
camphor.  If  these  are  inclined  to  move,  they  may  be  stopped  by 
dipping  a  finger  in  the  water.  Then  blow  a  cloud  of  lycopodium 
powder  over  the  surface  of  the  water,  so  as  to  cover  this  surface  uni- 
formly with  the  powder.  If  now  an  electrified  rod  is  dipped  repeatedly 
in  the  water,  wiping  it  dry  after  every  immersion,  and,  rubbing  it 
with  a  piece  of  flannel  before  dipping  in  the  water  again,  the  result 
will  be  that  the  pieces  of  camphor  will  move  as  if  gifted  with  life.  It 
will  be  noticed  at  the  same  time  that  the  surface  of  the  water  will  be 
almost  entirely  free  from  lycopodium,  as  the  powder  has  been  gradually 
removed  by  each  successive  immersion  of  the  electrified  rod,  which  at- 
tracts lycopodium  like  all  other  light  bodies.  If  now  we  suppose  that 
films  of  oily  matter  are  removed  in  the  same  way  by  an  electrified  rod, 
we  may  conceive  how  electricity  can  act  indirectly  in  removing  im- 
purities from  the  surface  of  the  water. 
There  would  remain  to  explain  why  films  of  oily  matter  or  other  im- 
purities act  as  a  check  on  camphor  motions  while  a  physically  clean 
water  surface  is  a  favorable  condition  in  producing  these  motions. 
Towards  the  solution  of  these  questions  I  will  venture  the  following 
explanation,  which  may  serve  as  the  base  of  further  researches. 
It  is  a  well  ascertained  fact  relating  to  camphor  motions,  that  when 
these  motions  take  place  the  camphor  dissolves  in  water  more  quickly 
than  when  the  camphor  is  at  rest.  I  think  that  a  connection  exists 
between  camphor  motions  and  the  three  following  facts  :  1st,  that  cam- 
phor dissolves  in  water  quite  easily  at  times ;  2d,  that  its  density  allows 
it  to  float  on  water ;  and  3d,  that  the  solution  has  a  density  slightly  diff- 
erent from  that  of  water.  I  am  not  prepared  at  present  to  develop 
these  ideas,  which  would  require  further  experiments  to  establish. 
I  will  confine  myself  to  the  well  ascertained  fact  that  a  piece  of 
camphor  wears  away  much  faster  when  in  motion  than  when  at  rest. 
