Theodor Weyl: A Pioneer of Urban Metabolism Studies
A discussion between researchers in the field of industrial ecology led to the question of whether Wolman's work on the urban metabolism (UM) of cities in 1965 was the first to quantify material flows of urban societies. This forum communication retrieves an apparently lost, but remarkable, work in the development of material flow analysis (MFA). That work is known as the 'Essay on the metabolism of Berlin,' published in 1894 by the renowned German chemist and medical doctor, Theodor Weyl. To investigate the nutrition situation among the population in the city of Berlin, Weyl investigated the nutrient flows discharged from the city and compared these values to the nutrient consumption through food intake. The title, approach, and wording make his work a forerunner of UM studies today. This forum contribution aims to introduce Weyl's work to an interdisciplinary international readership. Therefore, we (1) give a brief overview of Weyl's professional life, (2) summarize his study based on the German article, and (3) conclude with a discussion of the relevance of his study for the tool, MFA, and the concept of UM today. A major difference between his work and contemporary studies on UM is the motivation of the author. Weyl's aim was not to highlight the problems associated with excessive human consumption of resources and pollution of the environment, but to investigate the nutrition situation of a society with a significant degree of malnutrition. The existence of the latter, particularly in developing countries, makes Weyl's study still relevant.