1-157-537 - Oxford Science Archive/Heritage Images

Claude Louis Berthollet, French chemist. Berthollet (1748-1822) helped Antoine Lavoisier in his research into gunpowder and in devising the nomenclature that underpins the modern system for naming chemical compounds. He showed that ammonia was a compound of hydrogen and nitrogen, and in 1785 he demonstrated the effectiveness of using chlorine for bleaching. Obverse of a commemorative medal.