The remaining forty years of his life were full of activity—political, diplomatic, and scientific—and were spent mainly in London. In 1858 he was appointed a member of the first India Council, but resigned during 1859 on being sent to Persia as envoy extraordinary and minister plenipotentiary. The latter post he held for only a year, owing to his dissatisfaction with circumstances concerning his official position there. Previously he had sat in Parliament as Member of Parliament (MP) for Reigate from February to September 1858; he was again MP for Frome, from 1865 to 1868. He was appointed to the Council of India again in 1868, and continued to serve upon it until his death. He was a strong advocate of the forward policy in Afghanistan, and counselled the retention of Kandahar.