411 
Chemistry. “ Velocity of /‘ons at 0° C .” By Devendra Nath 
Bhattaoharyya and Nilratan Dhar. 
(Aangeboden door de Heeren Ernst Cohen en F- M. Jaeger). 
From time to time attempts have been made to determine accu- 
rately the mobilities of ions at ö°. Bat there is no systematic work 
in this line ; only isolated cases have been investigated. Even the 
velocity of hydrion at 0° is uncertain. An exact idea of our very 
much incomplete knowledge wonld be obtained from the folio wing 
summary of the work previonsly done. 
Wood *) was the first investigator in this line. Het determined the 
molecular conductivities of sodium chloride, potassinm chloride, 
dichloracetic acid, and trichloracetic acid at 0°, and at various 
dilutions. But his measurements are inaccurate as will be shown 
subsequently. Archibald * 2 3 ), Barnes s ) and Kohlrausch 4 ) also studied 
some electrolytes. Whetham 5 * * ) accurately determined the condnctivi- 
ties of some electrolytes at 0° ; but he did not attempt in deducing 
the velocities of individual ions at 0° from his measurements. 
Kahlenberg "), and Jones and his pupils r ) also studied some cases, 
but tlieir measurements are not accurate. The measurements of 
Noyes and Cooi/idge 8 9 ) agreed with those of Whetham. Evidently 
no systematic work is done in this line. 
The ionic mobilities of various ions are fairly accurately known 
at 18° or at 25° (Noyes and Falk — J. Amer. Cliem. Soc. 33 
(1911), 1436). But the value for hydrion (H°) is not exactly certain 
even at 18° or 25°. Ostwaed") tirst used the value 342 at 25°, and 
then raised it to 347 in Lehrbuch der Chemie 1893, 2, 675. KohL' 
raüsch’s 10 * * ) provisional value was 318 at 18° or 352 at 25°. Until 
recently, these values were accepted. Noyes’- 1 ), and then Noyes and 
Sammet 13 ) obtained the unexpectedly high value of 365 at 25°. Roth- 
1) Phil. Mag. 1896 (5) XL1, 117. 
2 ) Trans. Nov. Sco. Inst. Sci X, 33, 1898. 
») ibid X, 139, 1899. 
l ) Ann. Phys. Ghem. 1898, 66, 785 — 825. 
6 ) Phil. Trans. 1900. 
Proc. Roy. Soc. 71, 334 (1903). 
®) Journal. Phys. Cliem. 5, 339 (1901). 
7) Amer. Ghem. Journ. 25, 349 (1901); 26, 428 (1901); 34, 557 (1905). 
8 ) Carnegie rnstiUilion Publications 63, 47 (1907). 
9 ) Zeit. Phys. Ghem. 1888, 2, 842. 
lü ) Leitvermögen der Elektrolyte pp. 107 — 110, 200. 
A1 ) Zeit. Phys. Ghem. 1901, 36, 63—83. 
IS ) Zeit. Phys. Ghem. 1903, 43, 49. 
27 
Verslagen der Afdeeling Natunrk. Dl. XXIV. A°. 1915/16 
