mathematics: Numerical calculation: …Holland, in his short pamphlet La Disme (1585), introduced decimal fractions to Europe and showed how to extend the principles of Hindu-Arabic arithmetic to calculation with these numbers. Stevin emphasized the utility of decimal arithmetic “for all accounts that are encountered in the affairs of men,” and he explained in…

Simon Stevin: …Stevin published a small pamphlet, La Thiende (“The Tenth”), in which he presented an elementary and thorough account of decimal fractions and their daily use. Although he did not invent decimal fractions and his notation was rather unwieldy, he established their use in day-to-day mathematics. He declared that the universal…

Jan Kochanowski: …tragedy, Odprawa posłów greckich (1578; The Dismissal of the Grecian Envoys). With a plot from Homer’s Iliad and written in blank verse, it was performed at the royal court in Ujazdów near Warsaw in 1578 and was regarded as a political commentary on the contemporary situation in the country, which…

Disney Company: Continuing expansion: ABC, Pixar, Marvel Entertainment, and Lucasfilm: In addition to the long-running Disney Channel cable network, broadcasting interests were expanded to include the ABC network, the ESPN sports cable network, and Radio Disney.

Walt Disney Company is an American corporation best known as a purveyor of family entertainment. During the 20th and early 21st centuries, it became one of the world’s largest media conglomerates, with such holdings as ABC, ESPN, Pixar, Marvel Entertainment, and 20th Century Studios. Disney

figure skating: Ice shows: Disney on Ice began in 1981 and signed a number of top skaters to headline. Not surprisingly, it often presents Disney’s animated movie characters on ice.

Walt Disney World Resort, resort complex near Orlando, Florida, envisioned by Walt Disney and featuring attractions based on stories and characters created by the Disney Company. Following the success of Disneyland, near Anaheim, California, Disney began searching for a location for his second

Disney Company: Continuing expansion: ABC, Pixar, Marvel Entertainment, and Lucasfilm: …market under its own brand, Disney+, a subscription video service that collected the company’s film and television franchises on a single platform.

Walt Disney: First animated cartoons: …compelled Disney and his brother Roy—a lifelong business partner—to reopen shop in Hollywood.

Walt Disney was an American motion-picture and television producer and showman, famous as a pioneer of animated cartoon films and as the creator of such cartoon characters as Mickey Mouse and Donald Duck. He also planned and built Disneyland, a huge amusement park that opened near Los Angeles in

Walt Disney was an American motion-picture and television producer and showman, famous as a pioneer of animated cartoon films and as the creator of such cartoon characters as Mickey Mouse and Donald Duck. He also planned and built Disneyland, a huge amusement park that opened near Los Angeles in

Disneyland, amusement park in Anaheim, California, featuring characters, rides, and shows based on the creations of Walt Disney and the Disney Company. Though its central building, the Sleeping Beauty Castle, is modeled on Germany’s Neuschwanstein Castle, it is an unmistakable icon of American

Rachel McAdams: Doctor Strange and other later work: In 2017 McAdams starred in Disobedience, playing a woman whose marriage to an Orthodox rabbi is tested after the return of her former lover (played by Rachel Weisz). She later appeared in the comedies Game Night (2018) and Eurovision Song Contest: The Story of Fire Saga (2020). She then starred…

titration: …metal ions with the reagent disodium ethylenediaminetetraacetate (a salt of edetic acid, or EDTA). The indicators are dyes that have the property of forming a coloured complex with the metal ion. As the titration proceeds, the reagent reacts first with uncomplexed metal ions, and, finally, at the end point it…

disease, any harmful deviation from the healthy structural or functional state of an organism, generally associated with certain signs and symptoms and differing in nature from physical injury. A diseased organism commonly exhibits signs or symptoms indicative of its state of health. Thus, the

disorderly conduct, in law, intentional disturbing of the public peace and order by language or other conduct. It is a general term including various offenses that are usually punishable by minor penalties. Disorderly conduct may take the form of directly disturbing the peace, as when one

Frank Tashlin: Films of the 1960s: The Disorderly Orderly (1964), the last of the Tashlin-Lewis collaborations, was among their best and achieved cult status. Frenetic but also suspenseful and loaded with allusions to the films of Alfred Hitchcock—particularly Vertigo (1958)—it imagines Lewis as a failed medical student who takes a job…

Emil Kraepelin: …(either excessively active or inhibited); hebephrenia, characterized by inappropriate emotional reactions and behaviour; and paranoia, characterized by delusions of grandeur and of persecution.

disparate impact, judicial theory developed in the United States that allows challenges to employment or educational practices that are nondiscriminatory on their face but have a disproportionately negative effect on members of legally protected groups. When the U.S. Supreme Court first recognized

predication: …every referent (x); it is disparate if it fails to characterize some or all of the referents. The predication is formal if the subject necessarily entails (or excludes) the predicate; it is material if the entailment is contingent.

Francisco Goya: The Napoleonic invasion and period after the restoration: …Quinta del Sordo (1820–23) and Los proverbios or Los disparates, a series of etchings made at about the same time (though not published until 1864), are, on the other hand, nightmare visions in expressionist language that seem to reflect cynicism, pessimism, and despair.

A Void is a postmodern novel written by French author Georges Perec that was originally published in French as La Disparition (“The Vanishing”) in 1969. It was masterfully translated into English as A Void by Scottish novelist Gilbert Adair in 1994. Perec’s extended lipogram—a literary exercise

education: Indian universities: …by Sir Charles Wood’s epoch-making Dispatch of 1854, which led to (1) the creation of a separate department for the administration of education in each province, (2) the founding of the universities of Calcutta, Bombay, and Madras in 1857, and (3) the introduction of a system of grants-in-aid. Even when…

France: The development of central government: The Council for Dispatches (Conseil des Dépêches), or, more loosely, the Council for the Interior, had particular responsibility for home affairs, including the activities of the intendants; the Royal Council for Finances (Conseil Royal des Finances) supervised important matters affecting financial aspects of the king’s domain…

Sally Field: In 2020 she starred in Dispatches from Elsewhere, a series inspired by an alternate-reality game. She also appeared in the HBO series Winning Time: The Rise of the Lakers Dynasty (2022– ), about the famed NBA team.

Anderson Cooper: In the memoir Dispatches from the Edge (2006), Anderson discussed his offscreen life; in 2012 he publicly revealed that he was gay. The documentary Nothing Left Unsaid: Gloria Vanderbilt & Anderson Cooper appeared in 2016. He is also the host of the All There Is podcast, which explores…

dispensation, in Christian ecclesiastical law, the action of a competent authority in granting relief from the strict application of a law. It may be anticipatory or retrospective. Economy is the term that is normally employed in the Eastern Orthodox churches for this type of action. The church

Christian fundamentalism: Origins: …very different theological perspective, called dispensationalism. First taught to the Brethren in the mid-19th century, dispensationalism maintained that history is divided into distinct periods, or “dispensations,” during which God acts in different ways toward his chosen people. The present period, according to dispensationalism, was one of expectant waiting for the…

chimera: In dispermic chimeras, two eggs that have been fertilized by two sperm fuse together, producing a so-called tetragametic individual—an individual originating from four gametes, or sex cells. (Under normal circumstances, in the absence of zygote fusion, two fertilized eggs result in the production of dizygotic, or…

animal social behavior: Social interactions involving movement: The benefits of forming dispersal swarms, flocks, and coalitions are considered similar to the advantages of living in aggregations as both exploit the potential benefits of living in groups. Moving about in groups can provide additional advantages, such as the reduction in turbulence and energy savings accrued by geese…

Deepwater Horizon oil spill: Cleanup efforts: 8 million gallons of dispersants—substances that emulsified the oil, thus allowing for easier metabolism by bacteria—were pumped directly into the leak and applied aerially to the slick. Booms to corral portions of the slick were deployed, and the contained oil was then siphoned off or burned. As oil began…

Portuguese literature: From monarchy to republic: His Dispersão (1914; “Dispersion”) features exuberant images, an obsession with verbal constructions and metaphors, and experimentation with graphic design and fonts. The most versatile figure of Portuguese Modernism is José de Almada Negreiros, a poet, novelist, caricaturist, dancer, and actor who provoked scandal with his Manifesto…

azo dye: …anthraquinone vat dyes and some disperse dyes are also azo compounds; the latter are not water-soluble but can be suspended in water by soap and in that state are adsorbed from the suspension by cellulose acetate fibres.

water pollution: Types and sources of water pollutants: …from either point sources or dispersed sources. A point source is a pipe or channel, such as those used for discharge from an industrial facility or a city sewerage system. A dispersed (or nonpoint) source is a very broad unconfined area from which a variety of pollutants enter the water…

Deepwater Horizon oil spill: Cleanup efforts: 8 million gallons of dispersants—substances that emulsified the oil, thus allowing for easier metabolism by bacteria—were pumped directly into the leak and applied aerially to the slick. Booms to corral portions of the slick were deployed, and the contained oil was then siphoned off or burned. As oil began…

dispersion, in biology, the dissemination, or scattering, of organisms over periods within a given area or over the Earth. The disciplines most intimately intertwined with the study of dispersion are systematics and evolution. Systematics is concerned with the relationships between organisms and

dispersion, in wave motion, any phenomenon associated with the propagation of individual waves at velocities that depend on their wavelengths. Waves of any type can be described by a dispersion relation in which the wave frequency ω is given in terms of the wavenumber k, where k = 2π/λ, where λ is

animal social behavior: Social interactions involving movement: The benefits of forming dispersal swarms, flocks, and coalitions are considered similar to the advantages of living in aggregations as both exploit the potential benefits of living in groups. Moving about in groups can provide additional advantages, such as the reduction in turbulence and energy savings accrued by geese…

chemical association: …low temperatures the relatively weak London forces (i.e., forces acting between any two atoms brought close together) may also be strong enough to produce molecular association.

Deepwater Horizon oil spill: Cleanup efforts: 8 million gallons of dispersants—substances that emulsified the oil, thus allowing for easier metabolism by bacteria—were pumped directly into the leak and applied aerially to the slick. Booms to corral portions of the slick were deployed, and the contained oil was then siphoned off or burned. As oil began…

radiation: Dispersion: …with frequency is called a dispersion relation. For visible light the index of refraction increases slightly with frequency, a phenomenon termed normal dispersion. The degree of refraction depends on the refractive index. The increased bending of violet light over red by a glass prism is therefore the result of normal…

optics: Dispersion: The dispersive power (w) of the material is then defined as the ratio of the difference between the “F” and “C” indices and the “D” index reduced by 1, or,

form: …or 4-fold axis of symmetry; Disphenoid: four-faced closed form in which the two faces of a sphenoid alternate above two faces of another sphenoid; Prism: 3, 4, 6, 8, or 12 faces the intersection lines of which are parallel and (except for some monoclinic prisms) are parallel to a principal…

boomslang, (Dispholidus typus), venomous snake of the family Colubridae, one of the few colubrid species that is decidedly dangerous to humans. This moderately slender snake grows to about 1.8 metres (6 feet) in length and occurs in savannas throughout sub-Saharan Africa. When hunting, it lies in

marine ecosystem: Geography, oceanography, and topography: …are distinguished the euphotic and disphotic zones. The euphotic zone is the layer closer to the surface that receives enough light for photosynthesis to occur. Beneath lies the disphotic zone, which is illuminated but so poorly that rates of respiration exceed those of photosynthesis. The actual depth of these zones…

ship: Hydrostatics: …deadweight and lightship weight is displacement—that is, the weight that must be equaled by the weight of displaced water if the ship is to float. Of course, the volume of water displaced by a ship is a function of the size of that ship, but in turn the weight of…

Sigmund Freud: The interpretation of dreams: …second activity of the dreamwork, displacement, refers to the decentering of dream thoughts, so that the most urgent wish is often obliquely or marginally represented on the manifest level. Displacement also means the associative substitution of one signifier in the dream for another, say, the king for one’s father. The…

displacement, in mechanics, distance moved by a particle or body in a specific direction. Particles and bodies are typically treated as point masses—that is, without loss of generality, bodies can be treated as though all of their mass is concentrated in a mathematical point. In the figure, A is

displacement activity, the performance by an animal of an act inappropriate for the stimulus or stimuli that evoked it. Displacement behaviour usually occurs when an animal is torn between two conflicting drives, such as fear and aggression. Displacement activities often consist of comfort

sound: In air columns: …there of a velocity or displacement antinode similar to the centre of the fundamental mode of a stretched string, as illustrated at the top of Figure 4. On the other hand, the air at the closed end of a tube cannot move, so that a closed end results in a…

displacement current, in electromagnetism, a phenomenon analogous to an ordinary electric current, posited to explain magnetic fields that are produced by changing electric fields. Ordinary electric currents, called conduction currents, whether steady or varying, produce an accompanying magnetic

motorboat: Types.: …hulls used on motorboats are displacement hulls, which push through the water; and planing hulls, which skim across the water’s surface. The displacement hull has a V-shaped or round bottom, a relatively deep draft, a narrow width relative to its length, a sharp bow, and a narrow stern. The planing…

displacement law, in physics, any of the statements (originally formulated in 1913) that radioactive decay produces daughter atoms whose position in the periodic table of the chemical elements is shifted from that of their parents: two lower for alpha decay and one higher for negative beta decay.

sound: In air columns: …closed end results in a velocity node similar to the ends of a stretched string.

substitution reaction, any of a class of chemical reactions in which an atom, ion, or group of atoms or ions in a molecule is replaced by another atom, ion, or group. An example is the reaction in which the chlorine atom in the chloromethane molecule is displaced by the hydroxide ion, forming

tonnage: Displacement tonnage is used to define the size of naval ships. It refers to the weight of the volume of water displaced by a vessel in normal seagoing condition.

electric displacement, auxiliary electric field or electric vector that represents that aspect of an electric field associated solely with the presence of separated free electric charges, purposely excluding the contribution of any electric charges bound together in neutral atoms or molecules. If

information processing: Information display: For humans to perceive and understand information, it must be presented as print and image on paper; as print and image on film or on a video terminal; as sound via radio or telephony; as print, sound, and video in motion pictures, on television…

display behaviour, ritualized behaviour by which an animal provides specific information to others, usually members of its own species. Virtually all higher animals use displays to some extent. The best-known displays are visual ones—and some biologists restrict the term display to visual signals

zero-energy building: The United Kingdom’s EPC scheme: Display Energy Certificates (DECs) are also required for larger public buildings, thus enabling everyone to see how energy efficient the country’s public buildings are. The DEC has to be displayed at all times in a prominent place clearly visible to the public, and it is…

lek, in animal behaviour, communal area in which two or more males of a species perform courtship displays. Lek behaviour, also called arena behaviour, is found in a number of insects, birds, and mammals. Varying degrees of interaction occur between the males, from virtually none to closely

heraldry: Early writers: …Armorie (1562), and John Guillim, A Display of Heraldrie (1610), not only perpetuate the nonsensical natural history of olden days but are largely responsible for erroneous beliefs about heraldic charges having definite symbolic meanings and their being granted as rewards for valorous deeds—beliefs that today are perpetuated by the vendors…

metalwork: 16th century to modern: …known as “display pewter” (Edelzinn), and it gave a new and brilliant impetus to the trade. The first examples were made between 1560 and 1570, and the main centers of production were Nürnberg and Lyon. In the beginning the technique used was not the same in both towns. Whereas…

display resolution, number of pixels shown on a screen, expressed in the number of pixels across by the number of pixels high. For example, a 4K organic light-emitting diode (OLED) television’s display might measure 3,840 × 2,160. This indicates that the screen is 3,840 pixels wide and 2,160 pixels

rhythm: Polyphonic meter: …the spondee, ♩♩, and the dispondee, ♩♩♩♩, need an accent on the first beat to keep their identity. Notwithstanding the opposite tendencies of metrical organization and stress accent, however, some meter is obviously subject to stress, so that meter and time measure become very closely linked, as in the scherzo…

disposable income, that portion of an individual’s income over which the recipient has complete discretion. An accurate general definition of income is not easy to provide. Income includes wages and salaries, interest and dividend payments from financial assets, and rents and net profits from

Albert III Achilles: …24, 1473, he proclaimed the Dispositio Achillea (“Disposition of Achilles”), which was to preserve Brandenburg as a united whole and keep his dynastic inheritance intact. This settlement gave the mark of Brandenburg to his eldest son and the Hohenzollerns’s then more lucrative Franconian possessions to younger sons. While not establishing…

coal mining: Disposition: Disposition is the handling of the products of a preparation plant. The entire plant process includes ROM storage, raw coal storage, crusher house, screening plants, various slurries (coal-water mixtures), dewatering system, thickeners, thermal dryer, process-water systems, clean-coal storage, clean-coal load-out system, monitoring and process-control…

temperament, in psychology, an aspect of personality concerned with emotional dispositions and reactions and their speed and intensity; the term often is used to refer to the prevailing mood or mood pattern of a person. The notion of temperament in this sense originated with Galen, the Greek

epistemology: Occasional and dispositional knowledge: In contrast, dispositional knowledge, as the term suggests, is a disposition, or a propensity, to behave in certain ways in certain conditions. Although Smith may not now be thinking of his home address, he certainly knows it in the sense that, if one were to ask him…

John Berryman: Early poems: …volumes of poetry—Poems (1942) and The Dispossessed (1948)—followed. A richly erotic autobiographical sequence about a love affair, Berryman’s Sonnets, appeared in 1967. Berryman was a versatile man of letters: “The Lovers” appeared in The Best American Short Stories of 1946, and his story “The Imaginary Jew” (1945) is often anthologized.…

Ursula K. Le Guin: In The Dispossessed (1974), she examined two neighbouring worlds that are home to antithetical societies, one capitalist, the other anarchic, both of which stifle freedom in particular ways. The destruction of indigenous peoples on a planet colonized by Earth is the focus of The Word for…

eviction, the process of dispossessing a person of land, be it lawful or unlawful. Subject to any statutory provisions, it is lawful if the person evicted has a right to possession inferior to that of the person carrying out the eviction. The delivery of possession under order of the court is

oxide: Nonmetal oxides: …and reduced is called a disproportionation reaction. In the following disproportionation reaction, N4+ is reduced to N2+ (in NO) and oxidized to N5+ (in HNO3). 3NO2 + H2O → 2HNO3 + NO

Dispur, city, capital of Assam state, northeastern India. Following the administrative reorganization of the region in 1972, Dispur, a suburb of Guwahati, became the state

Raphael: Last years in Rome of Raphael: …of these frescoes are the Disputa and the School of Athens. The Disputa, showing a celestial vision of God and his prophets and apostles above a gathering of representatives, past and present, of the Roman Catholic Church, equates through its iconography the triumph of the church and the triumph of…

Gilbert Crispin: His skillful writings include Disputatio Iudaei et Christiani, in which a dialogue on the Christian faith is carried out between Gilbert and his Jewish acquaintance. Other historical and doctrinal works are De Simoniacis, De Spiritu Sancto, and Disputatio Christiani cum gentilli.

Western philosophy: Jewish thought: …was done by lecture and disputation (a formal debate). A lecture consisted of the reading of a prescribed text followed by the teacher’s commentary on it. Masters also held disputations in which the affirmative and negative sides of a question were thoroughly argued by students and teacher before the latter…

Raphael: Last years in Rome of Raphael: …of these frescoes are the Disputa and the School of Athens. The Disputa, showing a celestial vision of God and his prophets and apostles above a gathering of representatives, past and present, of the Roman Catholic Church, equates through its iconography the triumph of the church and the triumph of…

St. Robert Bellarmine: …lectures published under the title Disputationes de controversiis Christianae fidei adversus huius temporis haereticos (1586–93; “Lectures Concerning the Controversies of the Christian Faith Against the Heretics of This Time”). They contained a lucid and uncompromising statement of Roman Catholic doctrine. He took part in the preparation of the Clementine edition…

Nicolaus Copernicus: Early life and education: …known as Regiomontanus, 1436–76) and Disputationes adversus astrologianm divinatricenm (“Disputations against Divinatory Astrology”) by Giovanni Pico della Mirandola (1463–94). The first provided a summary of the foundations of Ptolemy’s astronomy, with Regiomontanus’s corrections and critical expansions of certain important planetary models that might have been suggestive to Copernicus of directions…

St. Robert Bellarmine: …lectures published under the title Disputationes de controversiis Christianae fidei adversus huius temporis haereticos (1586–93; “Lectures Concerning the Controversies of the Christian Faith Against the Heretics of This Time”). They contained a lucid and uncompromising statement of Roman Catholic doctrine. He took part in the preparation of the Clementine edition…

Francisco Suárez: …study in philosophy is the Disputationes Metaphysicae (1597), which was used for more than a century as a textbook at most European universities, Catholic and Protestant alike. In this work, which treats especially the problems of human will and the concept of general versus particular phenomena, Suárez drew upon Aristotle…

multilateralism: Dispute settlement: For the states to feel assured of the returns of treating their interests as indivisible, multilateral arrangements tend to incorporate some mechanism for ensuring that countries act in accordance with the expected norms. That principle of dispute settlement forms the third principle associated…

Frank Borzage: MGM tenure: …loaned to Paramount to make Disputed Passage (1939), about an older scientist (Akim Tamiroff) who advises his understudy (John Howard) that there can be no room for a wife (Dorothy Lamour) in the life of a true scientist. Back at MGM, Borzage was assigned to Strange Cargo (1940), a parable…

Torbern Olof Bergman: …Disquisitio de Attractionibus Electivis (1775; A Dissertation on Elective Attractions), in which he included tables listing the elements in the order of their affinity (their ability to react and displace other elements in a compound). These tables were widely acclaimed and were included in chemical literature as late as 1808.

arithmetic: Fundamental theory: …proved by Gauss in his Disquisitiones Arithmeticae. It states that every composite number can be expressed as a product of prime numbers and that, save for the order in which the factors are written, this representation is unique. Gauss’s theorem follows rather directly from another theorem of Euclid to the…

Alfred E. Green: …immediately made an impact with Disraeli (1929), Old English (1930), and The Green Goddess (1930), three showcases for stage veteran George Arliss, who won a best actor Academy Award for Disraeli. Smart Money (1931) was a taut crime yarn starring Edward G. Robinson, with James Cagney and

Eric Clapton: …having recorded such albums as Disraeli Gears (1967), Wheels of Fire (1968), and Goodbye (1969).

Benjamin Disraeli was a British statesman and novelist who was twice prime minister (1868, 1874–80) and who provided the Conservative Party with a twofold policy of Tory democracy and imperialism. Disraeli was of Italian-Jewish descent, the eldest son and second child of Isaac D’Israeli and Maria

Benjamin Disraeli was a British statesman and novelist who was twice prime minister (1868, 1874–80) and who provided the Conservative Party with a twofold policy of Tory democracy and imperialism. Disraeli was of Italian-Jewish descent, the eldest son and second child of Isaac D’Israeli and Maria

El Greco: Middle years: …the sacristy of Toledo Cathedral—the El Espolio (1577–79; The Disrobing of Christ). In designing the composition vertically and compactly in the foreground he seems to have been motivated by the desire to show the oppression of Christ by his cruel tormentors. He chose a method of space elimination that is…

congenital disorder: Disruptions: Disruptions are a group of congenital disorders that result from environmental disturbances of the processes of blastogenesis and organogenesis. Several classes of disruption have been recognized, including those due to prenatal infections such as rubella, cytomegalovirus, and toxoplasmosis; chemicals such as mercury,

Free Church of Scotland: …came to be known as the Disruption.

concealing coloration: In disruptive coloration, the identity and location of an animal may be concealed through a coloration pattern that causes visual disruption because the pattern does not coincide with the shape and outline of the animal’s body. Countershading is a form of concealing coloration in which the…

evolution: Diversifying selection: Two or more divergent phenotypes in an environment may be favoured simultaneously by diversifying selection. (See the right column of the figure.) No natural environment is homogeneous; rather, the environment of any plant or animal population is a mosaic consisting of more or…

Anura Kumara Dissanayake is the ninth executive president of Sri Lanka (2024– ) and leader of the leftist People’s Liberation Front (Janatha Vimukthi Peramuna; JVP). Dissanayake’s election marks a major turning point in Sri Lankan politics. Unlike most previous presidents, he does not come from a

cardiovascular disease: Other diseases of the aorta and the pulmonary artery: …it may lead to a dissecting aneurysm. In a dissecting aneurysm a rupture in the intima, the innermost coat of the artery, permits blood to enter the wall of the aorta, causing separation of the layers of the wall. Obstruction to tributaries may occur, which is usually associated with severe…

number game: Geometric dissections: Geometric dissection problems involve the cutting of geometric figures into pieces that can be arranged to form other geometric figures; for example, cutting a rectangle into parts that can be put together in the form of a square and vice versa. Interest in this…

Andreas Vesalius: Life: …much of his time to dissections of cadavers and insisted on doing them himself, instead of relying on untrained assistants. At first, Vesalius had no reason to question the theories of Galen, the Greek physician who had served the emperor Marcus Aurelius in Rome and whose books on anatomy were…