The worst manifestations of exhaustion were successfully cured by a long period of rest but it was immediately apparent to me that I had lost once and for all my former capacity for carrying out experimental work until physically tired.

; Jespersen O. Leipzig. Energetische Grundlagen der Kulturwissenschaft (1st ed.

Ostwald Jacobus Henricus van 't Hoff and Svante Arrhenius are usually credited with being the modern founders of the field of physical chemistry. He received the Nobel Prize in Chemistry in 1909 for his work on catalysis chemical equilibria and reaction velocities.