a 
ON ELECTROLYSIS AND ELECTRO-CHEMISTRY. 223 
_ The friction of the ions may be taken to be the same for most acids, 
since the motion is due mainly to the hydrogen, so that this may be put 
equal to a constant multiplied by (1+<af), where a is the temperature 
coefficient of the fluidity.' 
Whence 2. 
R,=A,c(1 +af). 
This function assumes a maximum value when 
(1+at)b=a or ateseted, 
boa 
There are obviously many rough-and-ready approximations in the 
course of this proof, but the remarkable fact remains that this behaviour 
of electrolytes of low conductivity was actually verified in the case of 
hypophosphorie acid and phosphoric acid, which gave maxima of con- 
ductivity at 54° and 74° respectively. A rough calculation of the tem- 
peratures at which the conductivity would reach its maximum value for 
other electrolytes gives the following results :— 
Temperature of 
Name ae a B Maximum 
<P Conductivity 
CHC1COOH . F 0:2 00162 0:0083 81° 
EE ce 5 E 02 0:0162 0:0117 56° 
C,H,COOH : 3 0-2 0:0162 0:0042 195° 
HNO, : oat 05 0:0157 00014 668° 
NaOH 05 00213 0:0011 882° 
4CuSO, 0-5 0:0256 0:0058 Tea KS 
ete 0-5 0:0231 0:0024 Boe 
NaCl. 0-5 0:0253 0:0012 808° 
It will be seen from the foregoing sketch that the various numerical 
relations between widely different properties of solutions and the agree- 
ment of calculated with observed results are so striking that the further 
development of the theory will be looked for with great interest. The 
part which the solvent plays is still unexplained, though it is becoming 
more and more clearly defined. 
§ d.—Hlectro-Chemical Thermodynamics ; 
§ e.—EHlectric Endosmose ; 
§ £—The Theory of Migration and Ionic Velocities; and 
§ g—Numerical Relations 
are reserved for the present. 
' According to Arrhenius, it is the temperature coefficient of molecular conductivity 
in infinite dilution. 
* A formula identical with this was suggested to me by a consideration of the 
numerical results for temperature variation of fluidity and conductivity of certain 
electrolytes. (Proc. Camb. Phil. Soc. vol. 7, p. 21, 1889.) 
