The Cycle of Life:
An History of Experimental Ecology

Sterling Memorial
Kline Sciences
Medical Historical
Exhibit Map

Selman Waksman, Humus: Origin, Composition, and Importance in Nature, 1938

Selman Waksman (1888-1973) extended Winogradsky’s influence in many ways: by adopting his research methods, participating in his expanding scientific network, assisting in publishing his 1949 collected works, and writing a laudatory biography of him. In Humus, Waksman applied Winogradsky’s methods and “cycle of life” perspective in his studies of humus (decaying organic material in the soil). For Waksman: The microorganisms influence the cycle of humus in nature in more than one way: 1. They bring about its formation from plant and animal residues. 2. They continuously transform humus and finally decompose it completely. 3. Their own cell substance contributes directly as a source of humus. The role of microorganisms in the cycle of organic matter in the soil, as well as in nature in general, is, therefore, indispensable.” (p. xiii)



Erasmus Darwin, Zoonomia, 1793
Charles Darwin, On the Formation of Vegetable Matter by Worms, 1881
Alexander von Humboldt, Cosmos, 1858
Dumas and Boussingault, Balance of Organic Matter, 1844
Ferdinand Cohn, Bacteria, The Smallest Living Beings, 1872
Louis Pasteur, Etudes sur la Biere, 1862
Selman Waksman, Sergei Winogradsky, 1953
Selman Waksman, Humus, 1939
Vladimir Vernadsky, Principles of Biogeochemistry, 1960
James Lovelock, An Homage to Gaia, 1985
Lloyd Ackert
Whitney Humanities Center
Yale University
53 Wall Street
P.O. Box 208298
New Haven, CT 06520-8298
Office: (203).432.3112

The Sterling Memorial Exhibit is located in the Overflow Case to the left of the circulation desk. The Sterling Memorial Library is located at

120 High Street
Yale University
New Haven, CT 06520
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