Limnology zoologist) and Einar Naumann (a Swedish botanist) co-founded the International Society of Limnology (SIL, from Societas Internationalis Limnologiae). Forel's original definition of limnology, "the oceanography of lakes", was expanded to encompass the study of all inland waters, and influenced Benedykt Dybowski's work on Lake Baikal. Prominent early American limnologists included G. Evelyn Hutchinson, Ed Deevey, E. A. Birge, and C. Juday. Physical properties of aquatic ecosystems are determined by a combination of heat, currents, waves and other seasonal distributions of environmental conditions. The morphometry of a body of water depends on the type of feature (such as a lake, river,
Subject of labor Subject of labor Subject of labor, or object of labor, is a concept in Marxist political economy that refers to "everything to which man's labor is applied." (Institute of Economics of the Academy of Sciences of the U.S.S.R., 1957) The subject of labor may be materials provided directly by nature like timber or coal, or materials that have been modified by labor. In the latter case, the subject of labor (e.g., yarn in a textile mill or semi-conductor chips in a computer assembly factory) are called "raw materials." The "subject of labor" is one of three basic factors of the