( 617 ) 
We will, for instance, make the calculation for 15° C.; a is *) 
than 15,67 and the equation (D) becomes : 
Zn 80, +- 0,620 Zn SO,. 15.67 H,0 = 1,620 Zn SO,. 6 H,O . (2) 
Calculating as before and using THOMSEN’s figures we find: 
W = 18430 + 0,620 x 441 + 1,620 X 843 = + 20069 calories 
and for the total heat evolved in the cell: 
E, = (23090 + 20069) — 175000 = $5459 calories . 
According to JAEGER’s measurements, for a cell containing un- 
dissolved Zn SO,. 6 H,0: 
E‚ = 1,400 — 0,00102 (£—39) — 0,000004 (t—39)2 . . (4). 
therefore 
Eis TE 1,4225 Volts. 
It further follows from (4) that 
dE 
(— = — 0,00102 + 48 X 0,000004 = — 0,000828 Volt 
a 
15° 
therefore 
E, = 2 (1,4225 + 288 X 0,000828) 22782 — 369% calories 
whilst caloric determinations gave Z,= 45859 calories an almost 
perfect agreement. 
Results of the research. 
1. The accepted views respecting the mechanism of the action 
of standard celis are incorrect, because insufficient attention has 
been paid to the actual phases of the substances which take part 
in the reactions going on in the cells. 
2. The representation of the reaction in the CLARK-normal cell 
by the equation: 
Zn + Hg,SO,= 2 Hg + Zn SO, 
as given for instance by NERNsT, must be replaced by the equations : 
t) Proceedings Royal Acad. Amsterdam. Vol. LI, p. 335. 
