518  M.  G.  Quincke  on  Electrolysis,  and  the 
another  occasion)  to  the  extraordinary  statements  there  made  by 
Professor  Wiillner.  At  present  I  must  content  myself  with  the 
remark  that  he  does  not  seem  to  have  read  even  Clausius's  paper 
on  Thermoelectricity ;  for  in  it  Thomson's  priority  as  regards  that 
subject  is  admitted. 
LXV.   On  Electrolysis,  and  the  Passage  of  Electricity  through 
Liquids.     By  G.  Quincke. 
[Continued  from  p.  375.] 
§55. 
IN  liquids  which  are  electrolyzed,  the  quantity  of  electricity 
passing  through  them  consists  of  two  parts.  The  one  consists 
of  the  particles  of  electricity  which  are  given  from  one  molecule 
to  the  adjacent  one,  which  pass  through  the  liquid  with  what  is 
called  metallic  conductivity ;  the  other  consists  of  the  particles 
of  electricity  which  are  carried  forward  in  the  liquid  by  material 
molecules*.  Now  the  first  part,  as  compared  with  the  second,  is 
extraordinarily  small — so  much  so,  in  fact,  that  the  very  exist- 
ence of  this  metallic  conductivity  is  often  denied f.  But  with 
a  sufficient  degree  of  approximation  we  may  regard  as  the  whole 
quantity  of  moving  electricity  that  which,  adhering  to  the  material 
molecules,  moves  simultaneously  with  them. 
If  p  is  the  number  of  molecules  of  salt  contained  in  the  unit 
of  volume  of  the  liquid,  a.  and  «'  the  equivalent-weights  of  the 
partial  molecules,  then 
a— pa,     a! —pa', (13) 
and  equations  (8)  pass  into 
*  Conf.  Kohlrausch  and  Weber,  "  Electrodynamische  Maassbestim- 
mungen,"  Abh.  d.  K.  S.  G.  d.  Wissensch.  vol.  v.  p.  272.  Faraday,  Phil. 
Mag.  S.  4.  vol  x.  (1855)  p.  107. 
t  From  the  simple  fact  that  no  substance  is  a  perfect  insulator,  it 
follows  that  all  must  have  some  conducting-power  of  the  same  kind  as  the 
metals.  No  solid  salt  which  is  not  decomposed  by  the  electrical  current  is 
a  complete  insulator;  and  hence,  if  the  opinion  above  expressed  were 
incorrect,  we  should  have  to  make  the  surprising  assumption  that  the  mere 
change  of  state  of  aggregation  in  one  series  of  compounds  (electrolyzable) 
destroyed  the  property  of  possessing  a  so-called  metallic  conductivity, 
while  in  other  (non-electrolyzable)  compounds  such  a  change  of  the  con- 
ducting-power could  not  occur  (compare  "  On  the  Conducting-power  of 
Chloride  of  Lead  and  Oxide  of  Lead,"  Buff,  Liebig's  Annalen,  vol.  c.  (1859) 
p.  285).  It  is  probable  that  Faraday's  law  does  not  hold  with  entire  strict- 
ness ;  but  the  deviations  are  so  small  that  they  lie  far  within  the  limits  of 
unavoidable  errors  of  observation. 
