program. Starting in the late 1930s he taught biodynamic farming and gardening at the Kimberton Farm School. One of his students, Paul Keene, who worked and studied with Pfeiffer there for two years and shortly thereafter co-founded Walnut Acres, recalls: "he helped bring all of life together for us in a definite coherent pattern". While at Kimberton, Pfeiffer led the initiative to found the Biodynamic Farming and Gardening Association, and to start its journal. While at Kimberton, Pfeiffer also met J. I. Rodale, founder of Organic Gardening and Farming magazine, and of the organic movement in the U.S. This relationship gave biodynamics a little-known place in the history of the American organic movement. Interpersonal difficulties - a motif of Pfeiffer's life - brought to a close the Kimberton Farms chapter. Aiming to continue his work training biodynamic farmers, Pfeiffer bought a farm in Chester, New York, where a small colony arose focused on farming, education, and the administration of the Biodynamic Association. His copper chloride sensitive crystallization theory brought him an honorary degree of Doctor of Medicine from Hahnemann Medical College and Hospital in Philadelphia in 1939. He studied chemistry and became a professor of nutrition in 1956. Pfeiffer wrote on the dangers of pesticides and DDT and Rachel Carson consulted with him when she was writing Silent Spring. In 1961, at his home in Spring Valley, N.Y., he suffered from a series of heart attacks, lingering for several days, but ultimately was not given the proper medical care and died. His wife subsequently took over the operation of their farm in Chester, New York. Work Pfeiffer was a pioneer of biodynamic agriculture in Europe, Britain, and America. He is most widely known for his innovative work in composting. He conducted extensive research on the preparation and use of biodynamic compost and was the inventor of BD Compost Starter, a compost inoculant. For many years Pfeiffer served as a compost consultant to municipal compost facilities, most notably Oakland, California, as well as countries in the Caribbean, Europe, and the Far East. A technical difficulty with the resulting compost, that it would not spread readily with the commonly used fertilizer spreader, could not be overcome and the project ultimately failed. Pfeiffer invented two anthroposophic Image forming methods, a method using a round filter chromatography (circular chromatography or chroma test) and the copper chloride crystallization method, developed together with Erika Sabarth. In