John Edmond was a geochemist the unifying theme of whose research was a quantitative understanding of the processes involved in the transfer of the chemical elements into and out of the oceans; in short, what controls ocean chemistry. He achieved this through oceanographic explorations sampling ocean waters for rare metals and explorations of hot springs on the deep sea floor, rivers from the Amazon to Siberia, and the rift valley lakes of Africa. This accompanied a strong background in chemistry and an almost reverent recognition of the value of data. John challenged established paradigms and pioneered developments in element and isotope systematics as applied to geochemical processes. He will alsobe remembered for his enthusiasm, his insight, his honesty, and his defence of anyone or any group he felt was badly treated.