metallurgist who, with his better-known cousin Sidney Gilchrist Thomas, devised in 1876–77 a process (thereafter widely used in Europe) of manufacturing in Bessemer converters a kind of low-phosphorus steel known as Thomas steel. In the Thomas–Gilchrist process the lining used in the converter is basic rather than acidic, and it captures the acidic phosphorus oxides formed upon blowing air through molten iron made from the high-phosphorus iron ore prevalent in Europe. Gilchrist, a graduate of the Royal School of Mines, London, was elected a Fellow of the Royal Society in 1891.