Robert Porrett was born 22 September 1783. When he was 11 he amused himself by drawing up and writing out official papers for his father, who was ordnance storekeeper of the Tower of London. This led to War Office officials offering Robert a post as an assistant in the department. He was appointed in 1795 and later became chief of the department and eventually retired in 1850. His position at The Tower led him to take an interest in antiquities.
He was elected Fellow of the Society of Antiquaries in 1840, and in 1848 he was elected Fellow of the Royal Society. He was an original fellow of the Chemical Society as well as a fellow of the Astronomical Society.
Porrett was not a professional chemist, but he did make some significant discoveries. In 1808 he found that by treating prussic acid with sulphuretted hydrogen a new acid was formed, he called it prussous acid. He was awarded a medal by the Society of Arts. In 1814 he discovered ferrocyanic acid. He also made a significant contribution to the field of physics with the discovery of electric endosmosis in 1816.
Porrett became a recognised authority on armour and contributed several papers to Archaeologia and the Proceedings of the Society of Antiquities.
Robert Porrett died 25 November 1868.