Note 258 — II A Sketch of the History of the Idea of Milieu Since the Beginning of the Nineteenth Century
Reading edition
Vide pp. 141–75 in Der Weltkrieg im Unterricht, Vorschläge u. Anregungen, etc. (Gotha: F. A. Perthes), esp. pp 163–5; he also discusses other phases of the relation between physical environment and the present war.