This study, originally published in 1972, examines the connections between human society and the rest of the universe that are attributable to economic activity. These include the inputs from the environment to industry, such as oxygen, used in the combustion of mineral fuels. Also included are the industrial outputs which are fed back into the environment in the form of waste products. An attempt will be made to establish functional relations between the extent and character of economic activity and the flow of materials in both directions between the economy and the environment. This title will be of interest to students of environmental and natural resource economics.