John de Sequeyra ( – ) was a Portuguese-born American physician and writer. Born in
Lisbon
Lisbon ( ; ) is the capital and largest city of Portugal, with an estimated population of 567,131, as of 2023, within its administrative limits and 3,028,000 within the Lisbon Metropolitan Area, metropolis, as of 2025. Lisbon is mainlan ...
into a
Portuguese Jewish family, he moved to the British
colony of Virginia
The Colony of Virginia was a British Empire, British colonial settlement in North America from 1606 to 1776.
The first effort to create an English settlement in the area was chartered in 1584 and established in 1585; the resulting Roanoke Colo ...
in 1745 and earned a living practising medicine. Sequeyra was the author of a group of writings on the various diseases in Virginia and the first visiting physician of the
Hospital for the Maintenance of Idiots, Lunatics, and Persons of Insane or Disordered Minds in
Williamsburg, Virginia
Williamsburg is an Independent city (United States), independent city in Virginia, United States. It had a population of 15,425 at the 2020 United States census, 2020 census. Located on the Virginia Peninsula, Williamsburg is in the northern par ...
.
Family and early life
João de Sequeira was born in Lisbon around 1712 into a
New Christian
New Christian (; ; ; ; ; ) was a socio-religious designation and legal distinction referring to the population of former Jews, Jewish and Muslims, Muslim Conversion to Christianity, converts to Christianity in the Spanish Empire, Spanish and Po ...
family from
Rio de Janeiro
Rio de Janeiro, or simply Rio, is the capital of the Rio de Janeiro (state), state of Rio de Janeiro. It is the List of cities in Brazil by population, second-most-populous city in Brazil (after São Paulo) and the Largest cities in the America ...
. His father was Francisco Machado de Sequeira (later Abraham de Sequeira Machado), a physician who was arrested in Rio de Janeiro in 1706 and taken to Lisbon two years later. His
Inquisition
The Inquisition was a Catholic Inquisitorial system#History, judicial procedure where the Ecclesiastical court, ecclesiastical judges could initiate, investigate and try cases in their jurisdiction. Popularly it became the name for various med ...
's trial lasted until June 1709. Francisco Machado de Sequeira moved to
London
London is the Capital city, capital and List of urban areas in the United Kingdom, largest city of both England and the United Kingdom, with a population of in . London metropolitan area, Its wider metropolitan area is the largest in Wester ...
in the early 1730s, where he was
circumcised
Circumcision is a procedure that removes the foreskin from the human penis. In the most common form of the operation, the foreskin is extended with forceps, then a circumcision device may be placed, after which the foreskin is excised. T ...
and took a Jewish name, Abraham de Sequeira Machado. Sequeira Machado became a member of
Bevis Marks Synagogue
Bevis Marks Synagogue, officially Qahal Kadosh Sha'ar ha-Shamayim (), is an Orthodox Judaism, Orthodox Judaism, Jewish congregation and synagogue, located off Bevis Marks, Aldgate, in the City of London, England, in the United Kingdom. The congr ...
in London.
Medical career
Sequeyra studied medicine in the
University of Leiden
Leiden University (abbreviated as ''LEI''; ) is a public research university in Leiden, Netherlands. Established in 1575 by William, Prince of Orange as a Protestant institution, it holds the distinction of being the oldest university in the Neth ...
beginning in 1736 and received his degree in 1739 with a dissertation entitled "De Peripneumonia vera", which he dedicated to his older brother "Joseph Henry de Siqueyra, M.D., physician to the Portuguese in the East Indies and chief physicist to the
Viceroy
A viceroy () is an official who reigns over a polity in the name of and as the representative of the monarch of the territory.
The term derives from the Latin prefix ''vice-'', meaning "in the place of" and the Anglo-Norman ''roy'' (Old Frenc ...
of
Goa
Goa (; ; ) is a state on the southwestern coast of India within the Konkan region, geographically separated from the Deccan highlands by the Western Ghats. It is bound by the Indian states of Maharashtra to the north, and Karnataka to the ...
".
In 1745, he moved to Williamsburg, Virginia, where he practiced medicine. Between 1745 and 1781 he compiled a manuscript entitled "Diseases in Virginia." He was a physician who attended about 85 households during a
smallpox
Smallpox was an infectious disease caused by Variola virus (often called Smallpox virus), which belongs to the genus '' Orthopoxvirus''. The last naturally occurring case was diagnosed in October 1977, and the World Health Organization (W ...
epidemic of 1747/8.
In 1769, Colonel
George Washington
George Washington (, 1799) was a Founding Fathers of the United States, Founding Father and the first president of the United States, serving from 1789 to 1797. As commander of the Continental Army, Washington led Patriot (American Revoluti ...
, as he was known then, frequently called in Dr. Sequeyra to treat his stepdaughter "Patsy," daughter of
Martha Park Custis. Patsy suffered from increasingly debilitating
epileptic seizures
A seizure is a sudden, brief disruption of brain activity caused by abnormal, excessive, or synchronous neuronal firing. Depending on the regions of the brain involved, seizures can lead to changes in movement, sensation, behavior, awareness, o ...
which eventually led to her death. In 1773, the first insane asylum in the
Thirteen Colonies
The Thirteen Colonies were the British colonies on the Atlantic coast of North America which broke away from the British Crown in the American Revolutionary War (1775–1783), and joined to form the United States of America.
The Thirteen C ...
, the
Hospital for the Maintenance of Idiots, Lunatics, and Persons of Insane or Disordered Minds, was built in Williamsburg, Virginia, and it remains in operation to this day. Dr. John de Sequeyra was the first visiting physician attached to the facility. In 1774, he became one of the directors of the hospital. So accomplished in caring for the residents, was Dr. Sequeyra, that when he retired in 1795 it took two doctors to back-fill his position.
Tomatoes
John Hill once wrote – "''Those who are us'd to eat with the Portuguese Jews know the value of it''"; he was speaking of the tomato. John Custis IV, a Williamsburg resident, sent a letter to Peter Collinson, in 1741, inquiring about this thing called a "tomato".
Tomatoes
The tomato (, ), ''Solanum lycopersicum'', is a plant whose fruit is an edible berry that is eaten as a vegetable. The tomato is a member of the nightshade family that includes tobacco, potato, and chili peppers. It originated from and was d ...
made their way to
Colonial America
The colonial history of the United States covers the period of European colonization of North America from the late 15th century until the unifying of the Thirteen British Colonies and creation of the United States in 1776, during the Re ...
by way of the
West Indies Slave Trade – it was a staple food of the slaves who learned to discern the poisonous varieties from the edible varieties.
Thomas Jefferson
Thomas Jefferson (, 1743July 4, 1826) was an American Founding Fathers of the United States, Founding Father and the third president of the United States from 1801 to 1809. He was the primary author of the United States Declaration of Indepe ...
himself informs us that introduction of the tomato as an edible fruit is due to the work of Dr. John de Sequeyra.
Works
Three writings on medical matters written by Sequeira are known, which remained in manuscript until the 20th century. One is an annual report on the diseases in Virginia, published by Harold Gill in 1972. Six years later, Gill published another Sequeira's writing on the same subject, a king of a short summary of the annual reports. In 1997, Sarah McEntee wrote a BA thesis on Sequeyra and included the transcription of a third manuscript, a list of prevailing diseases in Virginia, including their description, symptoms and therapies.
Notes and references
{{DEFAULTSORT:Sequeyra, John de
1710s births
Medical doctors from London
English emigrants
1719 deaths
English expatriates in the Netherlands
People from Williamsburg, Virginia
18th-century American physicians
18th-century American Sephardic Jews