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Henry Letheby
Henry Letheby (1816 – 28 March 1876) was an English analytical chemist and public health officer. Early life Letheby was born at Plymouth, England, in 1816, and studied chemistry at the Royal Cornwall Polytechnic Society. In 1837 he commenced the study of medicine and became the assistant of Jonathan Pereira. He graduated M.B. at the University of London in 1842, and was also LSA (Licentiate of the Society of Apothecaries) (1837) and PhD. Career He was a lecturer on chemistry at the London Hospital. For some years Letheby was also medical officer of health and analyst of foods for the City of London. He was also appointed chief examiner of gas for the metropolis under the Board of Trade. Letheby was an extremely accurate technological chemist and contributed many papers to ''The Lancet'' and other scientific periodicals. He was a fellow of the Linnean Society and the Chemical Society. Letheby's chief work was the treatise On Food, Its Varieties, Chemical Composition, Nutriit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henry Letheby
Henry Letheby (1816 – 28 March 1876) was an English analytical chemist and public health officer. Early life Letheby was born at Plymouth, England, in 1816, and studied chemistry at the Royal Cornwall Polytechnic Society. In 1837 he commenced the study of medicine and became the assistant of Jonathan Pereira. He graduated M.B. at the University of London in 1842, and was also LSA (Licentiate of the Society of Apothecaries) (1837) and PhD. Career He was a lecturer on chemistry at the London Hospital. For some years Letheby was also medical officer of health and analyst of foods for the City of London. He was also appointed chief examiner of gas for the metropolis under the Board of Trade. Letheby was an extremely accurate technological chemist and contributed many papers to ''The Lancet'' and other scientific periodicals. He was a fellow of the Linnean Society and the Chemical Society. Letheby's chief work was the treatise On Food, Its Varieties, Chemical Composition, Nutriit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Induction Coil
An induction coil or "spark coil" (archaically known as an inductorium or Ruhmkorff coil after Heinrich Rühmkorff) is a type of electrical transformer used to produce high-voltage pulses from a low-voltage direct current (DC) supply. p.98 To create the flux changes necessary to induce voltage in the secondary coil, the direct current in the primary coil is repeatedly interrupted by a vibrating mechanical contact called an interrupter. Invented in 1836 by Nicholas Callan, with additional research by Charles Grafton Page and others, the induction coil was the first type of transformer. It was widely used in x-ray machines, spark-gap radio transmitters, arc lighting and quack medical electrotherapy devices from the 1880s to the 1920s. Today its only common use is as the ignition coils in internal combustion engines and in physics education to demonstrate induction. Construction and function An induction coil consists of two coils of insulated wire wound around a common i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alumni Of The University Of London
Alumni (singular: alumnus (masculine) or alumna (feminine)) are former students of a school, college, or university who have either attended or graduated in some fashion from the institution. The feminine plural alumnae is sometimes used for groups of women. The word is Latin and means "one who is being (or has been) nourished". The term is not synonymous with "graduate"; one can be an alumnus without graduating ( Burt Reynolds, alumnus but not graduate of Florida State, is an example). The term is sometimes used to refer to a former employee or member of an organization, contributor, or inmate. Etymology The Latin noun ''alumnus'' means "foster son" or "pupil". It is derived from PIE ''*h₂el-'' (grow, nourish), and it is a variant of the Latin verb ''alere'' "to nourish".Merriam-Webster: alumnus .. Separate, but from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scientists From Plymouth, Devon
A scientist is a person who conducts Scientific method, scientific research to advance knowledge in an Branches of science, area of the natural sciences. In classical antiquity, there was no real ancient analog of a modern scientist. Instead, philosophers engaged in the philosophical study of nature called natural philosophy, a precursor of natural science. Though Thales (circa 624-545 BC) was arguably the first scientist for describing how cosmic events may be seen as natural, not necessarily caused by gods,Frank N. Magill''The Ancient World: Dictionary of World Biography'', Volume 1 Routledge, 2003 it was not until the 19th century in science, 19th century that the term ''scientist'' came into regular use after it was coined by the theologian, philosopher, and historian of science William Whewell in 1833. In modern times, many scientists have Terminal degree, advanced degrees in an area of science and pursue careers in various Sector (economic), sectors of the economy such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burials At Highgate Cemetery
Burial, also known as interment or inhumation, is a method of final disposition whereby a dead body is placed into the ground, sometimes with objects. This is usually accomplished by excavating a pit or trench, placing the deceased and objects in it, and covering it over. A funeral is a ceremony that accompanies the final disposition. Humans have been burying their dead since shortly after the origin of the species. Burial is often seen as indicating respect for the dead. It has been used to prevent the odor of decay, to give family members closure and prevent them from witnessing the decomposition of their loved ones, and in many cultures it has been seen as a necessary step for the deceased to enter the afterlife or to give back to the cycle of life. Methods of burial may be heavily ritualized and can include natural burial (sometimes called "green burial"); embalming or mummification; and the use of containers for the dead, such as shrouds, coffins, grave liners, and b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1876 Deaths
Events January–March * January 1 ** The Reichsbank opens in Berlin. ** The Bass Brewery Red Triangle becomes the world's first registered trademark symbol. * February 2 – The National League of Professional Base Ball Clubs is formed at a meeting in Chicago; it replaces the National Association of Professional Base Ball Players. Morgan Bulkeley of the Hartford Dark Blues is selected as the league's first president. * February 2 – Third Carlist War – Battle of Montejurra: The new commander General Fernando Primo de Rivera marches on the remaining Carlist stronghold at Estella, where he meets a force of about 1,600 men under General Carlos Calderón, at nearby Montejurra. After a courageous and costly defence, Calderón is forced to withdraw. * February 14 – Alexander Graham Bell applies for a patent for the telephone, as does Elisha Gray. * February 19 – Third Carlist War: Government troops under General Primo de Rivera drive through the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1816 Births
This year was known as the ''Year Without a Summer'', because of low temperatures in the Northern Hemisphere, possibly the result of the Mount Tambora volcanic eruption in Indonesia in 1815, causing severe global cooling, catastrophic in some locations. Events January–March * December 25 1815–January 6 – Tsar Alexander I of Russia signs an order, expelling the Jesuits from St. Petersburg and Moscow. * January 9 – Sir Humphry Davy's Davy lamp is first tested underground as a coal mining safety lamp, at Hebburn Colliery in northeast England. * January 17 – Fire nearly destroys the city of St. John's, Newfoundland. * February 10 – Friedrich Karl Ludwig, Duke of Schleswig-Holstein-Sonderburg-Beck, dies and is succeeded by Friedrich Wilhelm, his son and founder of the House of Glücksburg. * February 20 – Gioachino Rossini's opera buffa ''The Barber of Seville'' premières at the Teatro Argentina in Rome. * March 1 – The Gork ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Highgate Cemetery
Highgate Cemetery is a place of burial in north London, England. There are approximately 170,000 people buried in around 53,000 graves across the West and East Cemeteries. Highgate Cemetery is notable both for some of the people buried there as well as for its ''de facto'' status as a nature reserve. The Cemetery is designated Grade I on the Register of Historic Parks and Gardens. It is one of the Magnificent Seven cemeteries in London. Location The cemetery is in Highgate N6, next to Waterlow Park, in the London Borough of Camden. It comprises two sites, on either side of Swains Lane. The main gate is on Swains Lane just north of Oakshott Avenue. There is another, disused, gate on Chester Road. The nearest public transport ( Transport for London) is the C11 bus, Brookfield Park stop, and Archway tube station. History and setting The cemetery in its original formthe northwestern wooded areaopened in 1839, as part of a plan to provide seven large, modern cemeteries, now known a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holloway, London
Holloway is an inner-city district of the London Borough of Islington, north of Charing Cross, which follows the line of the Holloway Road ( A1). At the centre of Holloway is the Nag's Head commercial area which sits between the more residential Upper Holloway and Lower Holloway neighbourhoods. Holloway has a multicultural population. It is the home of Arsenal F.C., and was once home to the largest women's prison in Europe, Holloway Prison, until 2016. Holloway is in the historic county of Middlesex. History The origins of the name are disputed; some believe that it derives from '' Hollow'', or '' Hollow way'', due to a dip in the road caused by the passage of animals and water erosion, as this was the main cattle driving route from the North into Smithfield. In Lower Holloway, the former ''Back Road'', now Liverpool Road was used to rest and graze the cattle before entering London. Others believe the name derives from ''Hallow'' and refers to the road's historic significan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Golding Bird
Golding Bird (9 December 1814 – 27 October 1854) was a British medical doctor and a Fellow of the Royal College of Physicians. He became a great authority on kidney diseases and published a comprehensive paper on urinary deposits in 1844. He was also notable for his work in related sciences, especially the medical uses of electricity and electrochemistry. From 1836, he lectured at Guy's Hospital, a well-known teaching hospital in London and now part of King's College London, and published a popular textbook on science for medical students called ''Elements of Natural Philosophy''. Having developed an interest in chemistry while still a child, largely through self-study, Bird was far enough advanced to deliver lectures to his fellow pupils at school. He later applied this knowledge to medicine and did much research on the chemistry of urine and of kidney stones. In 1842, he was the first to describe oxaluria, a condition which leads to the formation of a particul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Back Emf
Counter-electromotive force (counter EMF, CEMF, back EMF),Graf, "counterelectromotive force", Dictionary of Electronics is the electromotive force (EMF) manifesting as a voltage that opposes the change in current which induced it. CEMF is the EMF caused by electromagnetic induction. Details For example, the voltage appearing across an inductor or coil is due to a change in current which causes a change in the magnetic field within the coil, and therefore the self-induced voltage. The polarity of the voltage at every moment opposes that of the change in applied voltage, to keep the current constant. The term ''back electromotive force'' is also commonly used to refer to the voltage that occurs in electric motors where there is relative motion between the armature and the magnetic field produced by the motor's field coils or permanent magnet field, thus also acting as a generator while running as a motor. This effect is not due to the motor's inductance, which generates a voltage i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Switch
In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type of switch is an electromechanical device consisting of one or more sets of movable electrical contacts connected to external circuits. When a pair of contacts is touching current can pass between them, while when the contacts are separated no current can flow. Switches are made in many different configurations; they may have multiple sets of contacts controlled by the same knob or actuator, and the contacts may operate simultaneously, sequentially, or alternately. A switch may be operated manually, for example, a light switch or a keyboard button, or may function as a sensing element to sense the position of a machine part, liquid level, pressure, or temperature, such as a thermostat. Many specialized forms exist, such as the toggle switch, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
