Jacob Augustus Lockhart Clarke (1817 – 25 January 1880) was a British

physiologist Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical a ...

and

neurologist Neurology (from el, νεῦρον (neûron), "string, nerve" and the suffix -logia, "study of") is the branch of medicine dealing with the diagnosis and treatment of all categories of conditions and disease involving the brain, the spinal c ...

who is primarily known for his studies of the brain and the

spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the spi ...

Life

Because his father died early, young Clarke was brought up by his mother in France. On returning to England he chose the medical profession, to which his elder brother and grandfather belonged, and studied at Guy’s Hospital, and

St Thomas' Hospital St Thomas' Hospital is a large NHS teaching hospital in Central London, England. It is one of the institutions that compose the King's Health Partners, an academic health science centre. Administratively part of the Guy's and St Thomas' NHS Foun ...

. Having obtained the diploma of the

Worshipful Society of Apothecaries The Worshipful Society of Apothecaries of London is one of the livery companies of the City of London. It is one of the largest livery companies (with over 1,600 members in 2012) and ranks 58th in their order of precedence. The society is a m ...

, he began practice at Pimlico, living with his mother. He became devoted to microscopical research on the brain and nervous system, and applying a new method, and proceeding with extreme care and thoroughness, he established many new facts of structure which had important bearings on the physiology and pathology of the nervous system. His first paper, ‘Researches into the Structure of the Spinal Cord,’ was received by the

Royal Society The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...

on 15 October 1850, and published in their ‘Transactions’ for 1851. It was illustrated, like many of his subsequent papers, by extremely accurate and valuable drawings by himself, and these have been subsequently reproduced in numerous works. Few men have ever done so much original work while occupied with general medical practice, as his successive papers in the Royal Society’s ‘Transactions’ and ‘Proceedings; the ‘Medico-Chirurgical’ transactions,’ the ‘Journal of the Microscopical Society.' He received the

Royal Medal The Royal Medal, also known as The Queen's Medal and The King's Medal (depending on the gender of the monarch at the time of the award), is a silver-gilt medal, of which three are awarded each year by the Royal Society, two for "the most important ...

of the Royal Society in 1861, and in 1867 he was elected an honorary follow of the King and Queen’s College of Physicians, Ireland. Late in life he attended St. George’s Hospital and qualified as a surgeon, still later obtained the M.D. St. Andrews (1869), and became a member of the

London College of Physicians The Royal College of Physicians (RCP) is a British professional membership body dedicated to improving the practice of medicine, chiefly through the accreditation of physicians by examination. Founded by royal charter from King Henry VIII in 1 ...

(1871), and entered upon consulting practice in nervous diseases. He became physician to the Hospital for Epilepsy and Paralysis, but gained no great amount of practice, probably owing to his retired habits, and his having published no book by which the public could judge of his work. He died on 25 January 1880 of

phthisis Phthisis may refer to: Mythology * Phthisis (mythology), Classical/Greco-Roman personification of rot, decay and putrefaction Medical terms * Phthisis bulbi, shrunken, nonfunctional eye * Phthisis miliaris, miliary tuberculosis * Phthisis pulmona ...

Work

Clarke was the first to establish the location of the dorsal nucleus of the spinal cord, calling it "posterior vesicular columns", and described the nucleus intermediolateralis. He also differentiated the medial

cuneate nucleus In neuroanatomy, the dorsal column nuclei are a pair of nuclei in the dorsal columns in the brainstem. The name refers collectively to the cuneate nucleus and gracile nucleus, which are present at the bottom of the medulla oblongata. Both nu ...

from the lateral cuneate nucleus (also called "Monakow's nucleus" after

neuropathologist Neuropathology is the study of disease of nervous system tissue, usually in the form of either small surgical biopsies or whole-body autopsies. Neuropathologists usually work in a department of anatomic pathology, but work closely with the clinic ...

Constantin von Monakow Constantin von Monakow (4 November 1853 – 19 October 1930) was a Russian-Swiss neuropathologist who was a native of Bobretsovo in the Vologda Governorate. He studied at the University of Zurich while working as an assistant at the Burghölzli I ...

). Clarke is credited with introducing the

histological Histology, also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures vis ...

technique of mounting cleared sections of tissue in

balsam Balsam is the resinous exudate (or sap) which forms on certain kinds of trees and shrubs. Balsam (from Latin balsamum "gum of the balsam tree", ultimately from Semitic, Aramaic ''busma'', Arabic ''balsam'' and Hebrew ''basam'', "spice", "perfume ...

media. He published numerous essays on the anatomy and physiology of the

medulla oblongata The medulla oblongata or simply medulla is a long stem-like structure which makes up the lower part of the brainstem. It is anterior and partially inferior to the cerebellum. It is a cone-shaped neuronal mass responsible for autonomic (involun ...

and spinal cord. He also had works published involving studies of

tetanus Tetanus, also known as lockjaw, is a bacterial infection caused by ''Clostridium tetani'', and is characterized by muscle spasms. In the most common type, the spasms begin in the jaw and then progress to the rest of the body. Each spasm usually ...

diabetes Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ap ...

paraplegia Paraplegia, or paraparesis, is an impairment in motor or sensory function of the lower extremities. The word comes from Ionic Greek () "half-stricken". It is usually caused by spinal cord injury or a congenital condition that affects the neural ...

and

muscular atrophy Muscle atrophy is the loss of skeletal muscle mass. It can be caused by immobility, aging, malnutrition, medications, or a wide range of injuries or diseases that impact the musculoskeletal or nervous system. Muscle atrophy leads to muscle weaknes ...

. The eponymous

Clarke's nucleus The posterior thoracic nucleus, (Clarke's column, column of Clarke, dorsal nucleus, nucleus dorsalis of Clarke) is a group of interneurons found in the medial part of lamina VII, also known as the intermediate zone, of the spinal cord. It is mainl ...

(also known as the

column of Clarke The posterior thoracic nucleus, (Clarke's column, column of Clarke, dorsal nucleus, nucleus dorsalis of Clarke) is a group of interneurons found in the medial part of lamina VII, also known as the intermediate zone, of the spinal cord. It is mainl ...

or as the "nucleus dorsalis of Clarke") is a name sometimes given for the dorsal nucleus of the spinal cord.

References

;Attribution

External links

Jacob Augustus Lockhart Clarke
at Who Named It? {{DEFAULTSORT:Clarke, Jacob Augustus Lockhart British neurologists British physiologists 1817 births 1880 deaths Royal Medal winners Fellows of the Royal Society 19th-century deaths from tuberculosis Tuberculosis deaths in England