D O C . 4 4 C O M M E N T O N PA P E R B Y H E S S 3 4 3
Published in Kolloid-Zeitschrift 27 (1920): 137. Received 3 August 1920, published September 1920.
[1]Heß 1920, written by Walter R. Heß (1881–1973), Professor and Director of the Physiological
Institute of the University of Zurich.
[2]Einstein’s dissertation appeared in 1905 (Einstein 1905j [Vol. 2, Doc. 15]); a slightly different
journal version was published the following year (Einstein 1906a). For historical background on Ein-
stein’s dissertation, see Vol. 2, the editorial note, “Einstein’s Dissertation on the Determination of
Molecular Dimensions,” pp. 170–182.
[3]In his paper, Heß quoted Einstein’s dissertation and eq. (1), but he derived a different expression
for the viscosity, namely .
[4]The experiments were performed by Jacques Bancelin, a student of Perrin’s. See Einstein 1911e
(Vol. 3, Doc. 14), note 2.
[5]The corrected formula, which was published in Einstein 1911e (Vol. 3, Doc. 14), was actually
found, at Einstein’s instigation, by his former collaborator Ludwig Hopf (see Einstein to Jean Perrin,
12 January 1911 [Vol. 5, Doc. 244]).
η′ η 1 ϕ) – ( ⁄ =