Elected F.R.S. 1982
Eric Hewitt was a plant physiologist, distinguished internationally for his research on the detection of deficiencies in trace elements in the mineral nutrition of plants and for elucidating the biochemical roles of some of these elements, particularly in the reduction of nitrate and nitrite ions. The research of his laboratory at Long Ashton Research Station, Bristol, was based on the meticulous applications of basic inorganic chemistry to techniques for sand–and–solution culture of experimental plants. Typically, trace elements are required by plants in concentrations of a few parts per million in the substrate in which they are grown. Consequently, to detect and measure effects of such nutrient elements on the growth of experimental plants, it is necessary to remove traces of these elements from the sand medium and from the plant nutrient solutions. His methods achieved astonishingly low levels of contaminating trace elements in plant growth media (Russell 1966, pp. 361–371). The element under study is then added to the test plant cultures at low concentration, and the growth and composition in test and control plants are compared. Hewitt's initial contribution was to devise techniques that could achieve such objectives. These techniques have been applied to solve problems of plant nutrition in agriculture and horticulture in many countries and they were the foundation on which his achievements in plant biochemistry were built.