John Malcolm Hirst, D.S.C. 20 April 1921 — 30 December 1997

John Malcolm Hirst, ‘Jim’ to all who knew him, was one of the leading aerobiologists of the twentieth century. He designed the Hirst spore-trap, an air sampler that made possible for the first time the routine quantitative and continuous estimation of spore and pollen concentrations in the atmosphere. Its use led to a breakthrough in the understanding of plant disease epidemics, to the identification of many airborne allergens and to the development of the national system of warnings for allergy sufferers.Before embarking on his scientific career, Jim Hirst served with distinction in World War II as a Lieutenant in the Royal Naval Volunteer Reserve. His research years were spent at Rothamsted Experimental Station, where he became Head of the Plant Pathology Department, a post he held for nine years. He then became Director of Long Ashton Research Station, which he sustained and strengthened through a period of great change. He also worked for international aid bodies, giving valuable guidance to agricultural research centres in developing countries.