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XLVII.   On  Electrolysis,  and  the  Passage  of  Electricity  through 
Liquids.     By  G.  Quincke*. 
SOME  time  ago,  in  a  paper  "  On  the  Transport  of  Material 
Particles  by  Current  Electricity,"  I  attempted  to  show  how 
a  series  of  phenomena  of  motion  which  current  electricity  brings 
into  play  may  be  simply  explained  if  we  assume  that  electricity 
is  excited,  not  merely  on  the  contact  of  two  metals,  but  also 
when  any  two  heterogeneous  bodies  are  in  contact.  This  as- 
sumption, which,  I  think,  must  necessarily  be  made  so  long 
as  no  definite  limits  can  be  drawn  between  various  bodies  as 
regards  their  electrical  deportment,  enables  us  to  conceive  the 
conduction  of  electricity  in  electrolytes  in  a  manner  similar  to 
that  in  the  paper  I  have  mentioned.  The  following  communi- 
cation, which,  with  the  exception  of  the  experiments  with  Thom- 
son's galvanometer,  was  written  as  long  as  six  years  ago,  is  a 
continuation  of  the  former,  and  is  intended  to  show  how  far  con- 
cordance between  theory  and  experiment  can  be  demonstrated. 
js-  Though,  from  our  ignorance  of  the  magnitude  of  the  resistance 
of  friction,  and  of  the  excitation  of  electricity  on  the  contact  of 
the  molecules,  we  cannot  predict  all  the  phenomena  of  electro- 
lysis, Faraday's  law  for  instance  (which  objection,  as  far  as  I 
know,  mightbe  raised  against  all  the  theories  hitherto  proposed), 
yet  we  can  do  it  for  a  great  number  of  phenomena  without 
having  recourse  to  new  hypotheses. 
§52. 
Let  us  first  suppose  an  electrolyte  of  linear  dimensions  through 
which  an  electrical  current  is  continually  flowing  in  the  direction 
of  the  positive,  x.  By  electrolyte  we  are  to  understand  a  body 
which  undergoes  some  change  in  its  chemical  condition  in  one 
or  more  parts  when  an  electrical  current  traverses  it.  To  fix  our 
ideas,  let  us  suppose  that  some  salt  (say,  chloride  of  sodium  in 
some  solvent  such  as  water)  is  the  electrolyte. 
No  substance  in  nature  is  a  perfect  insulator.  All  substances 
without  exception  conduct  electricity,  like  metals ;  only  they 
oppose  greater  resistance  to  the  motion  of  electricity  than  the 
metals.  Whether  a  different  kind  of  conduction  (what  is  called 
the  clectrolytical)  is  possible,  is  a  different  question,  which  must 
be  left  to  further  investigation  to  solve. 
It  is  assumed  that  each  of  the  partial  molecules  of  which  the 
total  molecule  is  made  up  has  a  definite  quantity  of  free  electri- 
city;  in  this  case  it  is  each  molecule  of  chlorine  and  each  mole- 
cule of  sodium :  let  each  sodium  molecule  have  the  quantity 
*  Translated  from  Poggendorff's  Annalen,  No.  9,  1871. 
Phil  Mag.  S.  4.  Vol  43,  No,  287.  May  1872.  2  B 
