( 99 ) 
Humphry Davy 1 2 * ), it attracted the attention of Faraday*), Gaugain*), 
PoGGENDORFF 4 5 ), HeNRICI 8 ), AmTOINE BECQUEREL 6 ), REGN AULT 7 ), WlLLARD 
Gibbs 8 ), Robb 9 ), Gabriel Lippmann 10 * * * * * ) and Spencer n ) and that theories 
to explain the polar exchange which was supposed to occur therein 
have not been wanting. We may state, however, that this pheno¬ 
menon does not take place if only due precautions are taken 
and that there is no question of a “conflict” with the second law 
of thermodynamics. 
3. In order to exclude secondary reactions our determinations for 
the measurement of the E.M.F. of different concentrated amalgams 
were carried out at 0\5. The details of the experiments will be 
described fully later on. It should be mentioned that the materials 
used comply with high demands as to purity. 
Chemically pure zinc possesses towards the solution of its salts a 
sharply defined potential, but only then when it has been deposited 
electrolytically in dendritic, or fungoid form 1 *). We replaced it by 
a 10°/ 0 amalgam such as is used in Clark’s normal cells and 
constructed H-shaped cells according to the scheme: 
Zinc amalgam I dilute solution I Zinc amalgam 
107, by weight | Zn °gQ J x % by weight 
The x% amalgams (x between 2,5 and 6%) used therein were 
prepared by weighing and melting the materials with special precau¬ 
tions. The amalgams were then introduced into the H-shaped cells. 
The amalgams of a lower concentration were investigated by means 
of the little apparatus shown in the Fig. 
*) Phil. Trans. Roy. Soc. 116, 405 (1826). 
2 ) Phil. Trans. Roy. Soc. 1884, Part. I 459 § 1004 en 1005. 
3) G. R. 42, 430 (1856). 
4 ) Poggendorffs Annalen 50, 262 (1840). 
5 ) Poggendorffs Annalen 58, 376 (1843). 
6 ) Traite d’Electricit6 et de Magnetisme, Paris 1854. Tome 1, p. 221. 
7 > Ann. de chim. et de physique (3) 44, 453 (1855). 
8 ) Transactions of the Connecticut Acad, of Arts and Sciences 3, 343 (1878). 
9 ) Wiedemanns Annalen, N. F. 20, 798 (1883). 
10 ) Journ. de Physique (2) 3, 388 (1884). 
ir ) Zeitschr. fur Elektrochemie 11, 681 (1905). 
Crova, Ann. de chim. et de phys. (3) 69, 458 (1863). 
Hockin and Taylor, Journ. Soc. Tel. Ing. 8, 282 (1879). 
St. Lindeck, Wiedemanns Ann. N. F! 35, 311 (1888). 
.. l8 ) Th. W. Richards and Lewis, Zeitschr. fur physik. Ghemie 28, 1 (1899), 
