Clark was born in
Cullen,
Banffshire,
Scotland, and was educated at
Fordyce School. He studied at
Aberdeen University, where he took an arts degree intending to study law, and graduated as a
M.A., before discovering a preference for medicine. He then went to
Edinburgh University, and in 1809 became a member of the
Royal College of Surgeons of Edinburgh. He then entered the medical service of the
Royal Navy. He served at the
Royal Hospital Haslar, in
Hampshire, until July 1810, when he was appointed assistant surgeon aboard . After the ship was wrecked in 1811 south of
Sandy Hook in
New Jersey, he returned to
Great Britain, where he was promoted to the rank of a surgeon and served successively on HMS
Colobrée, which was also wrecked, as well as on
Chesapeake and
Maidstone. In 1822, while in Rome, Clark published
Medical Notes on Climate, Diseases, Hospitals, and Medical Schools in France, Italy, and Switzerland, comprising an Inquiry into the Effects of a Residence in the South of Europe in Cases of Pulmonary Consumption. He also made contact with members of the European royal families and aristocracy, among them
Prince Leopold, later
King of the Belgians, as well as English aristocrats travelling in Europe. At Carlsbad (now
Karlovy Vary), Prince Leopold found Clark examining the waters and was struck with the desire to learn their uses. On his return to England, he appointed Clark as his physician. Clark returned to London in 1826 and was admitted as a Licentiate of the
College of Physicians and appointed physician to St George's Infirmary. He steadily built up a medical practice in London, and in 1829 published what was described as his "best and most important work",
The Influence of Climate in the Prevention and Cure of Chronic Diseases, more particularly of the Chest and Digestive Organs. In it, he systematised and popularised all that was known about the subject, and gave a more correct view of the powers of climate and mineral waters in the treatment of disease than had hitherto existed in the
English language. The book established his reputation in London and with the members of his profession. He promoted the use of
mineral waters to treat disease and became both famous and popular for the care he took in his prescriptions. He thought it "not beneath his notice or his dignity to study the art of prescribing practically, and by repeated trials, and his prescriptions compared favourably with those of most of his contemporaries." He was elected
Fellow of the Royal Society in 1832. ==Physician to Queen Victoria==