Pioneering toxicologist. Born in Edinburgh, Christison was educated at the University there and then worked as a doctor in the Edinburgh Infirmary (1817-20). He studied toxicology in Paris and was then appointed to a Chair of Medical Jurisprudence at the University of Edinburgh in 1822. In 1832 he transferred to a Chair of Materia Medica at the same institution, which he held for the next 45 years.
Christison made a significant contribution to the study of poisons and their effects on the body. He was noted for daring and potentially dangerous self-experimentation. In 1829, he published the first treatise on toxicology in the English language. He served as President of the Royal Society of Edinburgh and acted as a medical advisor to the Crown (1829-66) in which capacity he appeared as an expert witness in forensic toxicology in many celebrated criminal cases. He was also personal physician to Queen Victoria (1848).