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Bryce Canyon National Park

Bryce Canyon National Park is an American national park located in southwestern Utah. The major feature of the park is Bryce Canyon, which despite its name, is not a canyon, but a collection of giant natural amphitheaters along the eastern side of the Paunsaugunt Plateau. Bryce is distinctive due to geological structures called hoodoos, formed by frost weathering and stream erosion of the river and lake bed sedimentary rock. The red, orange, and white colors of the rocks provide spectacular views for park visitors. Bryce Canyon National Park is much smaller and sits at a much higher elevation than nearby Zion National Park. The rim at Bryce varies from 8000 to 9000 ft.

The Bryce Canyon area was settled by Mormon pioneers in the 1850s and was named after Ebenezer Bryce, who homesteaded in the area in 1874. The area was originally designated as a national monument by President Warren G. Harding in 1923 and was redesignated as a national park by Congress in 1928. The park covers 35835 acre and receives substantially fewer visitors than Zion National Park (nearly 4.3 million in 2016) or Grand Canyon National Park (almost 6 million in 2016), largely due to Bryce's more remote location. In 2023, Bryce Canyon received 2,461,269.

Geography
The park is located in southwestern Utah about 50 mi northeast of and 1000 ft higher than Zion National Park.

Bryce Canyon National Park lies within the Colorado Plateau geographic province of North America and straddles the southeastern edge of the Paunsaugunt Plateau west of Paunsaugunt Faults (Paunsaugunt is Paiute for "home of the beaver"). Park visitors arrive from the plateau and look over its edge toward a valley containing the fault and the Paria River just beyond it (Paria is Paiute for "muddy or elk water"). The edge of the Kaiparowits Plateau bounds the opposite side of the valley.

Bryce Canyon was not formed from erosion initiated from a central stream, meaning it technically is not a canyon. Instead headward erosion excavated large amphitheater-shaped features in the Cenozoic-aged rocks of the Paunsaugunt Plateau. This erosion resulted in delicate and colorful pinnacles called hoodoos that are up to 200 ft high. A series of amphitheaters extends more than 20 mi north-to-south within the park. The largest is Bryce Amphitheater, which is 12 mi long, 3 mi wide and 800 ft deep. A nearby example of amphitheaters with hoodoos in the same formation but at a higher elevation is in Cedar Breaks National Monument, which is 25 mi to the west on the Markagunt Plateau.

Rainbow Point, the highest part of the park at 9105 ft, is at the end of the 18 mi scenic drive. From there, Aquarius Plateau, Bryce Amphitheater, the Henry Mountains, the Vermilion Cliffs and the White Cliffs can be seen. Yellow Creek, where it exits the park in the northeast section, is the lowest part of the park at 6620 ft.

Climate
According to the Köppen climate classification system, the park has a continental climate with warm, dry summers (Dsb). Dsb climates are defined by having their coldest month at a mean temperature below 0 °C, all months with a mean temperature below 22 °C, at least four months with a mean temperature above 10 °C, and three times as much precipitation in the wettest winter month compared to the driest summer month. The plant hardiness zone at the visitor center is 5b with an average annual extreme minimum air temperature of -10.0 °F.

The weather in Bryce Canyon is cooler and receives more precipitation than Zion: a total of 15 to 18 in per year. Yearly temperatures vary from an average minimum of 9 °F in January to an average maximum of 83 °F in July, but extreme temperatures can range from -30 to 97 F. The record high temperature in the park was 98 F on July 14, 2002. The record low temperature was -26 F on February 6, 1989, and January 13, 1963.

Native American habitation
Little is known about early human habitation in the area. Archaeological surveys of the Paunsaugunt Plateau indicate that people have lived in the area for at least 10,000 years. Basketmaker Anasazi artifacts thousands of years old were found south of the park. Other artifacts from the Pueblo-period Anasazi and the Fremont culture (up to the mid-12th century) were found.

The Paiute Native Americans moved into the area around the time that the other cultures left. These Native Americans hunted and gathered for most of their food, while supplementing their diet with cultivated plants. The Paiute in developed a mythology surrounding the hoodoos. They believed that they were the Legend People whom the trickster Coyote turned to stone. One older Paiute said his culture called the hoodoos Anka-ku-was-a-wits, which is Paiute for "red painted faces".

European American exploration and settlement
In the late 18th and early 19th century the first European Americans explored the area. Mormon scouts visited in the 1850s to gauge its potential for agriculture, grazing, and settlement.

The first major scientific expedition was led by U.S. Army Major John Wesley Powell in 1872. Powell, along with a team of mapmakers and geologists, surveyed the Sevier and Virgin River area as part of a larger survey of the Colorado Plateaus. His mapmakers used many Paiute place names.

Small groups of Mormon pioneers followed and attempted to settle east of Bryce Canyon along the Paria River. In 1873, the Kanarra Cattle Company started to graze cattle there.

The Church of Jesus Christ of Latter-day Saints sent Scottish immigrant Ebenezer Bryce and his wife Mary to settle land in the Paria Valley to apply his carpentry skills. The Bryce family settled right below Bryce Amphitheater—the main collection of hoodoos. Bryce grazed his cattle inside what are now park borders, and reputedly thought that the amphitheaters were a "helluva place to lose a cow." He built a road to the plateau to retrieve firewood and timber, and a canal to irrigate his crops and water his animals. Other settlers soon started to call the unusual place "Bryce's Canyon", and the name stuck.

A combination of drought, overgrazing, and flooding eventually drove the remaining Paiutes from the area and prompted the settlers to attempt to build a water diversion channel from the Sevier River drainage. That effort failed, leading most settlers, including the Bryce family, to abandon the area. Bryce moved his family to Arizona in 1880. The remaining settlers dug a 10 mi ditch from the Sevier's east fork into Tropic Valley.

Creation of the park
These scenic areas were first described to the public in magazine articles published by Union Pacific and Santa Fe railroads in 1916. Forest Supervisor J. W. Humphrey among others promoted the scenic wonders of Bryce Canyon's amphitheaters, and by 1918 more articles helped to spark interest. However, poor access to the remote area and the lack of accommodations kept visitation to a bare minimum.

Ruby Syrett, Harold Bowman, and the Perry brothers later established lodging and "touring services". Syrett later served as the first postmaster. By the early 1920s, the Union Pacific Railroad became interested in expanding rail service into southwestern Utah to accommodate tourists.

Conservationists became alarmed by the damage overgrazing, logging, and unregulated visitation was inflicting on the canyon. A movement to protect the area soon started, and National Park Service Director Stephen Mather responded by proposing that Bryce Canyon be made into a state park. The governor of Utah and the Utah State Legislature lobbied for national protection. Mather relented and sent his recommendation to President Warren G. Harding, who on June 8, 1923, established Bryce Canyon National Monument.

A road was built the same year on the plateau to provide access to outlooks over the amphitheaters. From 1924 to 1925, Bryce Canyon Lodge was built from local timber and stone.

Members of the United States Congress started work in 1924 on upgrading Bryce Canyon's protection status from national monument to national park to establish Utah National Park. A process led by the Utah Parks Company for transferring ownership of private and state-held land to the federal government started in 1923. The last of the land was acquired four years later, and on February 25, 1928, Bryce Canyon National Park was established.

In 1931, President Herbert Hoover annexed an adjoining area south of the park, and in 1942 an additional 635 acres was added. This brought the park's total area to the ultimate 35835 acres. Rim Road, a scenic drive, was completed in 1934 by the Civilian Conservation Corps. Park administration was conducted from Zion National Park until 1956 when Bryce Canyon's first superintendent started work.

Later
The USS Bryce Canyon, named for the park, served as a supply and repair ship in the U.S. Pacific Fleet from September 15, 1950, to June 30, 1981.

Bryce Canyon Natural History Association (BCNHA) is a non-profit organization, established in 1961. It runs the bookstore inside the park visitor center and support interpretive, educational, and scientific activities. A portion of the profits from all bookstore sales are donated to public land units.

Responding to increased visitation and traffic congestion, NPS implemented a voluntary, summer-only, in-park shuttle system in June 2000. In 2004, reconstruction began on the road system.

On April 7, 2020, Bryce Canyon National Park was closed to help prevent the spread of COVID-19, before a phased reopening started on May 6, 2020.

Geology

The Bryce Canyon area experienced soil deposition that spans from the last part of the Cretaceous period and the first half of the Cenozoic era. The ancient depositional environment varied. Dakota Sandstone and Tropic Shale were deposited in the warm, shallow waters of the advancing and retreating Cretaceous Seaway (outcrops of these rocks are found just outside park borders). The colorful Claron Formation, source of the hoodoos, was laid deposited in a system of cool streams and lakes that existed from 63 to about 40 million years ago (from the Paleocene to the Eocene epochs). Sediment types changed as the lakes deepened and filled and as the shoreline and river deltas migrated.

Other formations were created, but mostly eroded away following two major periods of uplift. The Laramide orogeny affected the entire western part of what would become North America starting about 70 million to 50 MYA. This event helped to build the Rocky Mountains and in the process closed the Cretaceous Seaway. The Straight Cliffs, Wahweap, and Kaiparowits formations were victims of this uplift. The Colorado Plateaus rose 16 MYA and were segmented into plateaus, separated by faults and each having its own uplift rate. The Boat Mesa Conglomerate and the Sevier River Formation were later removed by erosion.

This uplift created vertical joints, which over time preferentially eroded. The soft Pink Cliffs of the Claron Formation eroded to form freestanding hoodoo pinnacles in badlands, while the more resistant White Cliffs formed monoliths. The brown, pink, and red colors are from hematite (iron oxide; Fe2O3); the yellows from limonite (FeO(OH)*nH2O); and the purples are from pyrolusite (MnO2). Also created were arches, natural bridges, walls, and windows. Hoodoos are composed of soft sedimentary rock and are topped by a piece of harder, less easily eroded stone that protects the column. Bryce Canyon has one of the highest concentrations of hoodoos on Earth.

The formations are part of the Grand Staircase. The oldest members of this supersequence of rock units are exposed in the Grand Canyon, intermediate ones in Zion National Park, and the youngest appear in the Bryce Canyon area. A small amount of overlap occurs in and around each park.

Ecology
More than 400 native plant species live in the park. The three life zones in the park are based on elevation: The lowest areas are dominated by dwarf forests of pinyon pine and juniper with manzanita, serviceberry, and antelope bitterbrush in between. Aspen, cottonwood, water birch, and willow grow along streams. Ponderosa pine forests cover the mid-elevations with blue spruce and Douglas fir in water-rich areas and manzanita and bitterbrush as underbrush. Douglas fir and white fir, along with aspen and Engelmann spruce, make up the forests on the Paunsaugunt Plateau. The harshest areas have limber pine and ancient Great Basin bristlecone pine, some more than 1,600 years old.

The forests and meadows support diverse animal life including foxes, badgers, porcupines, elk, skunks, black bears, bobcats, and woodpeckers. Mule deer are the most common large mammals. Elk and pronghorn, which have been reintroduced nearby, sometimes appear.

The park forms part of the habitat of three wildlife species listed under the Endangered Species Act: the Utah prairie dog, the California condor, and the southwestern willow flycatcher. The Utah prairie dog is a threatened species that was reintroduced to the park. The largest protected population is found in the park.

About 170 species of birds visit the park each year, including swifts and swallows. Most species migrate to warmer regions in winter, although jays, ravens, nuthatches, eagles, and owls do not. In winter, the mule deer, cougars, and coyotes migrate to lower elevations. Ground squirrels and marmots pass the winter in hibernation.

Eleven species of reptiles and four species of amphibians have been found. Reptiles include the Great Basin rattlesnake, short-horned lizard, side-blotched lizard, striped whipsnake, and amphibians include the tiger salamander.

Also in the park are the black, lumpy, very slow-growing colonies of cryptobiotic soil, which are a mix of lichens, algae, fungi, and cyanobacteria. Together these organisms slow erosion, add nitrogen to the soil, and help it to retain moisture.

Activities

Most park visitors travel the scenic drive, which provides access to 13 viewpoints over the amphitheaters.

In total, 50 mi of trails criss-cross the park. Bryce Canyon has eight marked and maintained day hikes:

Easy to moderate hikes

 * Mossy Cave (one hour, State Route 12 northwest of Tropic)
 * Rim Trail (5–6 hours, anywhere on the rim)
 * Bristlecone Loop (one hour, Rainbow Point), and Queens Garden (1–2 hours, Sunrise Point)

Moderate hikes

 * Navajo Loop (1–2 hours, Sunset Point)
 * Tower Bridge (2–3 hours, north of Sunrise Point)

Strenuous hikes

 * Fairyland Loop (4–5 hours, Fairyland Point)
 * Peekaboo Loop (3–4 hours, Bryce Point)

Several of the trails intersect, allowing hikers to arrange routes for more challenging hikes.

The park has two trails designated for overnight trips: the 9 mi Riggs Spring Loop Trail and the 23 mi Under-the-Rim Trail. Both require a backcountry camping permit.

More than 10 mi of marked but ungroomed skiing trails are available off of Fairyland, Paria, and Rim trails. 20 mi of connecting groomed ski trails are in nearby Dixie National Forest and Ruby's Inn.

The air is so clear that on most days Navajo Mountain and the Kaibab Plateau can be seen 90 mi away in Arizona from Yovimpa and Rainbow points. On clear days, the Black Mesas of eastern Arizona and western New Mexico can be seen some 160 mi away.

The park has a 7.4 magnitude night sky, one of the darkest in North America. Stargazers can, therefore, see 7,500 stars, while in most places fewer than 2,000 can be seen due to light pollution, and in many large cities only a few dozen are visible. Park rangers host public stargazing events and evening programs on astronomy, nocturnal animals, and night sky protection. The Bryce Canyon Astronomy Festival, typically held in June, attracts thousands of visitors. In honor of this festival, Asteroid 49272 was named after the national park.

The two campgrounds are North Campground and Sunset Campground. Loop A in North Campground is open year-round. Additional loops and Sunset Campground are open from late spring to early autumn. The 114-room Bryce Canyon Lodge is another way to stay overnight.

title: Bryce Canyon National Park


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Czech literature

Czech literature can refer to literature written in Czech, in the Czech Republic (formerly Czechoslovakia, earlier the Lands of the Bohemian Crown), or by Czech people.

Most literature in the Czech Republic is now written in Czech, but historically, a considerable part of Czech literary output was written in other languages as well, including Latin and German.

Middle Latin works
Bohemia was Christianized in the late 9th to 10th centuries, and the earliest written works associated with the kingdom of Bohemia are Middle Latin works written in the 12th to 13th centuries (with the exception of the Latin Legend of Christian, supposedly of the 10th century but of dubious authenticity). The majority of works from this period are chronicles and  hagiographies. Bohemian hagiographies focus exclusively on Bohemian saints (Sts. Ludmila, Wenceslas, Procopius, Cyril and Methodius, and Adalbert), although numerous legends about Bohemian saints were also written by foreign authors. The most important chronicle of the period is the Chronica Boemorum (Bohemian Chronicle) by Cosmas, though it does approach its topics with then-contemporary politics in mind, and attempts to legitimize the ruling dynasty. Cosmas' work was updated and extended by several authors in the latter part of the 12th and during the 13th centuries.

During the first part of the 13th century, the Přemyslid rulers of Bohemia expanded their political and economic influence westward and came into contact with the political and cultural kingdoms of Western Europe. This cultural exchange was evident in literature through the introduction of German courtly poetry, or Minnesang, in the latter part of the 13th century. After the murder of Wenceslas III and the subsequent upheavals in the kingdom in 1306, however, the Bohemian nobles distanced themselves from German culture and looked for literature in their native language. Despite this, German remained an important literary language in Bohemia until the 19th century. This new literature in Czech consisted largely of epic poetry of two types: the legend and the knightly epic, both based on apocryphal tales from the Bible, as well as hagiographic legends of earlier periods. Prose was also first developed during this period: administrative and instructional texts, which necessitated the development of a more extensive and specialized vocabulary; the first Czech-Latin dictionaries date from this time. Extensive chronicles, of which the Chronicle of Dalimil and Chronicon Aulae Regiae (the Zbraslav Chronicle) are the most striking examples, and artistic prose (e.g. Smil Flaška z Pardubic and Johannes von Saaz) were also written.

Reformation
The Hussite revolution of the 15th century created a definite break in the literary evolution of Czech literature and forms its own separate history within Czech literature. The main aim of this literature was to communicate and argue for a specific religious doctrine and its form was generally prose. Jan Hus theological writing first appears at the beginning of the 15th century; he wrote first in Latin, later in Czech, and this divide remained for much of the later period: poetry and intellectual prose used primarily Latin, whereas popular prose was written in Czech or German. Hus writings center on technical, theological questions; however, he did publish a set of his Czech sermons and created rules of orthography and grammar that would be used to create the foundations of modern Czech in the 17th and 18th centuries. Only fragments remain of the literary works of the radical Taborite faction – these were generally Latin apologia defending the Taborite doctrine (Mikuláš Biskupec z Pelhřimova, Petr Chelčický). In general, Hussite writings differed from the preceding era by their focus on social questions – their audience consisted of the lower and lower middle classes. Works defending Catholicism and attacking the Hussite utraquists were also written, one example being Jan Rokycana's works. The Hussite period  also developed the genre of Czech religious songs as a replacement for Latin hymns and liturgy, e.g. the Jistebnický kancionál, the Jistebnice Hymnal.

After the election of George of Poděbrady to the Czech throne following the Hussite wars, a new cultural wave swept into Bohemia. Humanism saw in the classics of antiquity an ideal for literature and culture. The main feature of the literature of this period is the competition between Catholics writing in Latin, e.g. Bohuslav Hasištejnský z Lobkovic and Jan Dubravius) and Protestants writing in Czech, e.g. Viktorin Kornel of Všehrdy and Václav Hájek. New literary devices incited scholars, e.g. Veleslavín, to construct a more complex grammatical structure, based on Latin, as well as an influx of loan words. Gutenberg's printing press rendered books and pamphlets more accessible, which slowly changed literature's status in society.

Baroque period
The demise of the Czech Protestants after the Battle of the White Mountain decidedly affected Czech literary development. The forceful re-Catholicization and Germanization of Bohemia and the ensuing confiscations and expulsions virtually eliminated the Protestant middle classes and split the literature into two parts: the domestic Catholic and the émigré Protestant branches. Unlike in other European countries of the time, the nobility in Bohemia was not a part of the literary audience and thus this split of literary effort led to a certain lack of development and stagnation of Czech baroque literature in comparison to other European countries of the time, especially in genres that were written for noble courts. The largest personality of Czech evangelical baroque writing is John Comenius, who spent his youth in Bohemia but was forced into exile later in life. He was a pedagogue, theologian, reformer of education, and philosopher; his works include grammars, theoretical tracts on education, and works on theology. With his death in the late 17th century, Protestant literature in Czech virtually disappeared. Catholic baroque works span two types: religious poetry such as that of Adam Michna z Otradovic, Fridrich Bridel and Václav Jan Rosa, and religious prose writings (i.e. homiletic prose and hagiographies), and historical accounts (Bohuslav Balbín), as well as the Jesuit St. Wenceslas Bible.

The Enlightenment
At the end of the 18th century, the Bohemian lands underwent a considerable change – the Habsburg emperor Josef II put an end to the feudal system and supported a new religious and ideological tolerance. Enlightened classicism emerged, which sought to apply the principles of rational science to all aspects of daily life. A national culture and literature in one's own national language began to be seen as a prerequisite for the unification of a nation. In literature, this constituted a renewed interest in prose novels (e.g. Václav Matěj Kramerius), in Czech history and in the historical development of Czech culture (e.g. Josef Dobrovský, who re-codified the grammar of Czech and Antonín Jaroslav Puchmayer, who systematically set out to develop a Czech poetic style). The literary audience evolved from priests and monks to the laity and general public and literature began to be seen as a vehicle of artistic expression. Bohemia and Moravia, however, remained within the sphere of Austrian and German cultural influence. The new national literature thus firstly mimicked popular German genres and would only later evolve into an independent creative effort; this was especially true for drama, e.g. Václav Kliment Klicpera.

19th century
Pre-romanticism formed the transition between enlightened classicism and romanticism – the pre-romantics did not completely abandon the emphasis on poetic forms drawn from antiquity, but relaxed the strict separation between the genres and turned away from didactic genres toward more lyric, folk-inspired works (e.g. Ján Kollár and František Čelakovský.) It was during this period that the idea of a truly national literature and culture developed, as a rejection of Bernard Bolzano's vision of a bi-lingual and bi-cultural Czech-German state. The perhaps greatest figure of this era is Josef Jungmann, who translated many classics of world literature and spent his life establishing Czech literature as a serious, rich literature capable of great development. František Palacký and Pavel Jozef Šafárik took up the challenge of reexamining Czech history. As part of the effort to establish a pedigree for Czech literature and culture, Czech historians of the time sought evidence of heroic epics of the Middle Ages. They appeared to find such evidence in the Rukopis královédvorský and Rukopis zelenohorský (the Dvůr Králové Manuscript and the Zelená Hora Manuscript, respectively), although both were later proven forgeries.

By the 1830s, the foundations of Czech literature were laid and authors now began to focus more on the artistic merits of their work and less on developing the idea of Czech literature and culture as a whole. During this time period two main types of literature were produced: Biedermeier literature, which strove to educate the readers and encourage them to be loyal to the Austro-Hungarian Empire (e.g. Karel Jaromír Erben and Božena Němcová), and romanticism, which emphasized the freedom of the individual and focused on subjectivity and the subconscious (e.g. Karel Hynek Mácha, Václav Bolemír Nebeský.) These authors were generally published in either newspapers or in the literary magazine Květy (Blossoms) published by Josef Kajetán Tyl.

The year 1848 brought to the fore a new generation of Czech authors who followed in the footsteps of Mácha, and published their work in the new almanac Máj (May) (e.g. Vítězslav Hálek, Karolina Světlá and Jan Neruda). These authors rejected the narrow ideal of a purely national culture and favored one that incorporated Czech literature into European culture and drew inspiration from the progress made outside of the Czech lands. Their work, however, also commented on the encroachment of industrialization and focused increasingly on the simple life as opposed to the unfettered romantic ideal.

The May generation was followed by the neo-romantics, who continued in the romantic tradition, but also incorporated more contemporary styles: realism, Symbolism, and decadence. Three periods are apparent: the first reacted to the disappointment due to the lack of political and social progress during the 1870s (e.g. Václav Šolc); the second was the great return to poetry, especially epic poetry (e.g. Josef Václav Sládek); and the third focused on prose (e.g. Alois Jirásek).

In conversation with the neo-romantics, the next generation of authors leaned toward realism and naturalism, the ordinary and banal. They favored contemporary subjects over historical ones, and sought to deemphasize the personal voice of the author in comparison to the often highly colored speech of the characters. Two main topics were of interest: the exploration of the Czech village and the extent to which it remained an oasis of good morals (Jan Herben, Karel Václav Rais, Alois Mrštík); and Prague, especially the life of the lower classes (Ignát Herrman, Karel Matěj Čapek Chod).

The last literary generation of the 19th century signaled a decided break with the past and the advent of modernism – after the wave of optimism in the wake of the French Revolution at the beginning of the century, the lack of progress in implementing these ideals of freedom and brotherhood led to both a skepticism toward the possibility of ever achieving these ideals, and renewed efforts to do so. The common link between authors of this generation is their adherence to a particular style over their own voices, and their often very critical perspectives on the work of the previous generations. The modernists also inaugurated the cult of the artist, and this period saw the birth of the literary critic as an independent profession, as an ally of the artist, helping to both define and present work to the public (František Xaver Šalda). Notable poets of this period drew on the works and translations of the poet Jaroslav Vrchlický and include, among others, Josef Svatopluk Machar, Antonín Sova, Otokar Březina, and Karel Hlaváček); prose authors include Vilém Mrštík, Růžena Svobodová, and Josef Karel Šlejhar.

20th century
The turn of the 20th century marked a profound shift in Czech literature — after nearly a century of work, literature finally freed itself from the confines of needing to educate and serve the nation and spread Czech culture, and became literature simply for the sake of art. The orientation toward France, Northern Europe, and Russia intensified, and new demands were laid on the cultural knowledge of authors and their audience.

The new generation of poets distanced themselves from both the neo-romantics and the modernists: led by S. K. Neumann, their work focused on concrete reality, free of any pathos, or complicated symbolism. Many of the new poets (Karel Toman, Fráňa Šrámek, Viktor Dyk, František Gellner, Petr Bezruč) allied themselves with anarchism and the women's movement, although this influence waned throughout the decade. In prose, the work of the modernist generation was only now coming into its own, but the different stylistic waves that affected their prose are also evident in the work of the new generation — naturalism (A. M. Tilschová); impressionism (Šrámek, Gellner, Jiří Mahen, Jan Opolský, Rudolf Těsnohlídek); the Vienna Secession (Růžena Svobodová, Jiří Karásek ze Lvovic).

After their rebellious first decade, the new generation of poets (Toman, Neumann, Šrámek) turned toward nature and life in their work. This decade also marked the return of Catholic authors (Josef Florian, Jakub Deml, Jaroslav Durych, Josef Váchal) and the first entrance of the avant-garde into Czech literature, seeking to document the rapid changes in society and modernization. The first avantgarde style was neoclassicism, which soon gave way to cubism, futurism, and civilism (S. K. Neumann, the young brothers Čapek).

World War I brought with it a wave of repression of the newly emergent Czech culture, and this meant a return to the past, to traditional Czech values and history: the Hussites and the Awakening. The war, however, also precipitated a crisis of values, of faith in progress, religion, and belief, which found outlet in expressionism (Ladislav Klíma, Jakub Deml, Richard Weiner), civilism (Čapek brothers) and visions of a universal brotherhood of mankind (Ivan Olbracht, Karel Matěj Čapek Chod, F. X. Šalda).

The interwar period, coinciding with the First Republic, is one of the apogees of Czech literature — the new state brought with it a plurality of thinking, religion, and philosophy, leading to a great flowering of literature and culture. The first major theme of the interwar period was the war — the inhumanity, violence, and terror, but also the heroic actions of the Czech Legion (Rudolf Medek, Josef Kopta, František Langer, Jaroslav Hašek). An antiwar comedy novel The Good Soldier Švejk by Jaroslav Hašek is the most translated novel of the Czech literature (58 languages as of 2013).

A new generation of poets ushered in the return of the avantgarde: poetry of the heart (early Jiří Wolker, Zdeněk Kalista) and naivism (Čapek brothers, Josef Hora, Jaroslav Seifert, and S. K. Neumann). The avantgarde soon split, however, into the radical proletarian socialist and communist authors (Wolker, Neumann, Karel Teige, Antonín Matěj Píša, Hora, Jindřich Hořejší), the Catholics (Durych, Deml), and to the centrists (brothers Čapek, Dyk, Fischer, Šrámek, Langer, Jan Herben). A specifically Czech literary style, poetism, was developed by the group Devětsil (Vítězslav Nezval, Jaroslav Seifert, Konstantin Biebl, Karel Teige), which argued that poetry should pervade everyday life, that poetry is inseparable from daily life, that everyone is a poet. Prose of the interwar period distanced itself even more from the traditional, single perspective prose of the previous century, in favor of multiple perspectives, subjectivity, and fractured narratives. Utopian and fantastic literature came into the forefront (Jan Weiss, Karel Čapek, Eduard Bass, Jiří Haussmann), as well as the genres of documentary prose, which sought to paint as accurate a picture of the world as possible (Karel Čapek, Egon Erwin Kisch, Jiří Weil, Rudolf Těsnohlídek, Eduard Bass, Jaromír John, Karel Poláček); lyrical, imaginative prose that allied itself with the poetic poetry of the time (Karel Konrád, Jaroslav Jan Paulík, Vladislav Vančura); and Catholically-oriented prose (Jaroslav Durych, Jan Čep, Jakub Deml). The drama of the time also followed the same stylistic evolution as poetry and prose — expressionism, followed by a return to realistic, civilian theater (František Langer, Karel Čapek). Along with avantgarde poetry, avantgarde theater also flourished, focusing on removing the barriers between actors and audience, breaking the illusion of the unity of a theatrical work (Osvobozené divadlo, Jiří Voskovec and Jan Werich).

After the heady optimism of the 1920s, the 1930s brought with them an economic crisis, which helped spur a political crisis: both the left (Communist) and right (anti-German and fascist) parties radicalized and threatened the stability of the democracy. This led the authors of the time to focus on public matters and spirituality; Catholicism gained in importance (Kalista, Karel Schulz, Halas, Vančura, Durych). Changes were apparent first in poetry: the new generation of poets (Bohuslav Reynek, Vilém Závada, František Halas, Vladimír Holan, Jan Zahradníček) began as poets, but their work is much darker, full of images of death and fear. The older avantgarde (Teige, Nezval) also turned away from poetism to surrealism, and a third group (Hora, Seifert, František Hrubín) turned instead to lyricism, to quiet, memory-filled poetry. Prose, after the years of realistic journalism, turned to epics, existential novels, and subjective perspectives. Folk-inspired ballads (Josef Čapek, K. Čapek, Vančura, Ivan Olbracht), social-themed novels (Olbracht, Vančura, Poláček, Marie Majerová, Marie Pujmanová), and psychological novels (Jarmila Glazarová, Egon Hostovský, Jaroslav Havlíček) appeared. During this period, Karel Čapek wrote his most politically charged (and well-known) plays in response to the rise of fascist dictators. After the Munich Agreement in 1938, literature once more mirrored the current political present and called for national solidarity and a return to the past.

The German protectorate and World War II left its mark on Czech literature — many of the authors of the interwar generations did not survive or went into exile. During 1938–1940, society was still relatively free, but during 1941, most of the free newspapers, magazines, and publishers were shut down, and authors were silenced. WWII thus marks the origin of the 3-way split of literature that continued throughout the socialist years until 1989: domestic published, domestic illegal, and exile literature. As a result of the war, all forms of literature turned even more toward tradition and history: poetry became more subdued, and greater emphasis was laid upon language as an expression of national identity (Hora, Halas, Seifert, Nezval), and on spirituality and religious values (Hrubín, Závada, Zahradníček, Holan). The same occurred in prose: gone were the experimental works of the interwar period, but the social and psychological novel (Václav Řezáč, Vladimír Neff, Miloš Václav Kratochvíl) remained. The historical novel marked a new resurgence (Kratochvíl, Vančura, Durych, Schulz) as a way to write about the present while cloaking it in historical novels, as did prose inspired by folk tales and folk culture (Josef Štefan Kubín, Jan Drda, Vančura, Jaromír John, Zdeněk Jirotka). The generation of authors that debuted during the war and shortly afterwards (Jiří Orten, Group 42) all shared a similar harrowing experience of the war; their works all bear the hallmark of tragedy, existentialist thought, and the focus on the person as an isolated being.

Czech postwar literature is tightly intertwined with the political state of postwar Czechoslovakia; as during the war, literature broke apart into three main branches: domestic published, domestic illegal, and exile literature. Literature under the communist regime became the refuge of freedom and democracy, and literary works and authors were valued not only for their literary merits, but also for their struggle against the regime. The literature of the entire postwar period thus enjoyed great attention, despite its often precarious position. During the first three years after the end of the war (1945–1948), however, literature maintained a certain degree of freedom, although the strengthening of the extreme left gradually pushed out of the public sphere first the Catholic authors (Deml, Durych, Čep, Zahradníček), then the moderate Communists.

1948 brought the ultimate victory of the Communists, and the subsequent end of civil freedoms — any literature contrary to the official perspective was banned and the authors persecuted. The official literary style became socialist realism and all avantgarde leanings were suppressed. Many authors went into exile — to Germany, the U.S., the Vatican. Of those that stayed, many chose to write in secret and remain unpublished (the surrealists (Zbyněk Havlíček, Karel Hynek), Holan, Zahradníček, Jiří Kolář, Josef Jedlička, Jan Hanč, Jiřina Hauková, Josef Škvorecký, Egon Bondy, Jan Zábrana, Bohumil Hrabal). Most of their works were published only during the 1960s and 1990s.

Only at the end of the 1950s did the tight censorial control begin to ease — some poets were allowed to publish again (Hrubín, Oldřich Mikulášek, Jan Skácel) and a new literary group formed around the magazine Květen, striving to break the hold of socialist realism (Miroslav Holub, Karel Šiktanc, Jiří Šotola). Prose lagged behind poetry for much of the period, with the exception of Edvard Valenta and Josef Škvorecký. Shorter works, such as the short story also became popular again.

The 1960s brought with them the beginnings of reform efforts in the Communist party, and the subsequent liberalization of literature and increasing prestige of authors. Beginning with 1964, literature began to broaden in scope beyond the officially approved style. In poetry, intimate lyricism became popular (Vladimír Holan), as well as epic poetry (Karel Šiktanc, Hrubín), and the realism of Group 42. In prose, new authors abandoned polemics about socialism and instead turned toward personal and civic morality (Jan Trefulka, Milan Kundera, Ivan Klíma, Pavel Kohout), the theme of war and occupation (Jiří Weil, Arnošt Lustig), especially the fate of Jews. Bohumil Hrabal became the most prominent of the contemporary prose authors, with his works full of colloquialisms and non-traditional narrative structures, and the absence of official moral frameworks. Toward the end of the decade, novels of disillusionment, skepticism, and a need to find one's place in the world and history begin to appear (Vaculík, M. Kundera, Hrubín), as do modern historical novels (Oldřich Daněk, Jiří Šotola, Vladimír Körner, Ota Filip). The 1960s also brought the debuts of a new generation of authors who grew up during the excesses of Stalinism, and thus had no ideals about world utopias — their works dealt not with changing the world, but with living in it: authenticity, responsibility both moral and literary. These included the poets Jiří Gruša, Josef Hanzlík, Antonín Brousek, Jiří Kuběna, and playwrights Ivan Vyskočil, Jiří Šlitr, Václav Havel, Milan Uhde, Josef Topol. The close of the reform years also saw a return to experiments: surrealism (Milan Nápravník, Vratislav Effenberger), nonsense poetry (Emanuel Frynta), experimental poetry (Josef Hiršal, Bohumila Grögerová, Emil Juliš), abstract poetry and dada (Ladislav Novák), gritty realistic prose (Jan Hanč, Vladimír Páral) and ornate, symbol filled fantasy (Věra Linhartová). The era of literary freedom and experiments, which reached its apogee during the Prague Spring of 1968, came to an abrupt end the same summer, with the Soviet invasion and subsequent "normalization."

Normalization reinstated the severe censorship of the 1950s, shut down most of the literary magazines and newspapers, and silenced authors who did not conform. More than ever before, literature split into the legal, illegal, and exile branches. Many authors fled to the U.S. and Canada (Josef Škvorecký), Germany (Peroutka), Austria (Kohout), France (M. Kundera), but they generally did not fare much better than their contemporaries in Czechoslovakia, largely due to the absence of a readership. Their works became better known only through translations. The work of experimental, avantgarde authors who continued to publish as "official" authors generally shrank in quality, conformed to the official dogma, although in comparison to the 1950s, the literature was less rigid, less wooden. On the border between official and unofficial literature stood authors of historical novels (Korner, Karel Michal), and well as Bohumil Hrabal and Ota Pavel. Seifert, Mikulášek, Skácel were all also barred from publishing; their work was published as samizdat, small underground presses that hand-published much of the work of the underground, illegal authors. Ludvík Vaculík, Jan Vladislav, and Václav Havel and Jan Lopatka organized the largest samizdat editions. It was many of these illegal authors who signed Charta 77 and were jailed for doing so. Samizdat literature again returned to Catholicism, to memoirs and diaries of daily life (Vaculík). Memory and history were also chief motifs of samizdat literature (Karel Šiktanc, Jiřina Hauková), as were brutally honest, factual testimonials of daily life (Ivan Martin Jirous). The new literary generation of the 1980s was marked by the need to rebel, to act outside of the bounds of society — their work draws on the war generation (Group 42), and is often brutal, aggressive, and vulgar (Jáchym Topol, Petr Placák, Zuzana Brabcová); postmodernism also influenced literature as a whole (Jiří Kratochvil, Daniela Hodrová).

The fall of communism in 1989 marked another break in Czech literature — plurality and freedom returned. The works of many of the illegal and exiled authors working under the communist regime were published for the first time (for instance Jan Křesadlo and Ivan Blatný) and many of them returned to public life and publishing. Although some critics would say that contemporary Czech literature (since 1989) is relatively marginalised in comparison with Czech film-making, writers such as Petr Šabach, Ivan Martin Jirous, Jáchym Topol, Miloš Urban, Patrik Ouředník, Petra Hůlová, Michal Viewegh and Kateřina Tučková are public figures and sell books in large numbers. Contemporary Czech poetry, in Petr Borkovec can boast a poet of European standing.

Contemporary Czech authors

 * Michal Ajvaz
 * Jan Balabán
 * Josef Formánek
 * Ivan Martin Jirous
 * Jiří Hájíček
 * Emil Hakl
 * Petra Hůlová
 * Milan Kundera
 * Patrik Ouředník
 * Sylvie Richterová
 * Jaroslav Rudiš
 * Pavel Řezníček
 * Petr Stančík
 * Michal Šanda
 * Jáchym Topol
 * Miloš Urban
 * Jaroslav Velinský
 * Michal Viewegh
 * Radka Denemarková
 * Jaroslav Čejka (* 1943)
 * Pavel Šrut

Czech Literary Awards

 * Jaroslav Seifert Prize
 * Jiří Orten Award
 * Magnesia Litera Prize

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Czech literature


text:
Jaroslav Foglar

Jaroslav Foglar (6 July 1907 – 23 January 1999) was a Czechoslovak writer who wrote many novels about youths (partly also about the Boy Scouts movement) and their adventures in nature and dark city streets. His signature series is Rychlé šípy, which was adapted into comics by Jan Fischer.

Early life
Foglar was born in 1907 and grew up in Prague. Because his father died prematurely, he was brought up in rather poor material conditions by his mother. To earn some extra money young "Slavik" used to copy the popular detective stories, cliftonky, earning 20 heller per copy. (This initially affected his literary style, and some of the first editions of his books were corrected later, to get rid of the literary slag.)

He was strongly influenced by the romantic parts of Prague. All of the fictional towns in his novels are more or less derived from it. During the 1920s, Foglar was strongly influenced by the German independent Wandervogel movement as well as the Scout movement led by Antonín Benjamin Svojsík under the Czech name Junák.

Writer and editor career, prohibited writer and the end of life
During the 1930s and 1940s, Foglar worked as a magazine editor in one of the largest Prague publishing houses, Melantrich. He edited several journals for youths: and he wrote articles for other journals including the Skaut, Sluníčko, ABC, and the Tramp.
 * Mladý hlasatel ("Young herald"), 1938–1941
 * Junák ("Scout"), 1945–1949
 * Vpřed ("Ahead"), 1946–1948

After the Communist coup in 1948 Foglar was kicked out of the publishing house, his magazines were liquidated and his books prohibited, as was the Scout movement and independent youth clubs. For many years he worked as a tutor in boarding schools and youth homes. During the fall of censorship at the end of the 1960s, he published some new books and re-editions of the older ones. After the Soviet occupation of Czechoslovakia his books were once again banned until 1989.

Foglar lived with his mother, caring for her until her death in high age, and never married.

Scout versus Youth Club movement
Although Foglar worked as a Boy Scout leader, his relation to the Scout movement was not straightforward. He portrayed the Boy Scouts only in a few of his novels (especially Pod junackou vlajkou and Devadesatka pokracuje), preferring to write mostly about his own invention, the boy clubs.

Foglar's idea of independent boy clubs is basically derived from the German Wandervogel movement. As editor of Mladý Hlasatel, Foglar systematically built clubbist ideology (based on friendship, good deeds, personal sacrifice, love of the nature, etc.) on some and traditions and own terminology. Clubs were small groups between 4 and 8 youths. Some of them were informally led by young men few years older than the other youths, like Rikitan in the novel Hoši od Bobří řeky or by the best of the youths - like the 'exemplary youth' Mirek Dušín of the Rychlé šípy Club.

With Foglar's novels and magazine articles as examples, many Czech youths established such clubs. In the golden age of club movement, there were thousands of such independent clubs, which presented a type of Wandervogel-like alternative to the organized Scout movement. On the other hand, when Scouts were persecuted and forbidden during the German occupation between 1938 and 1945 and during Communism between 1948 and 1989 (with the short exception of renewal of Scout during 1968 and 1969), boy clubs posed an excellent informal alternative of youth life based on ideas similar to those of the Scouts.

Ideal friendship and Ideal of male education
One of the key themes of Foglar's novels is the tension between the loneliness and close friendship between young male heroes. These are especially distinctive in the novels 'Přístav volá', 'Když duben přichází', 'Chata v Jezerní kotlině', 'Modrá rokle' and 'Tajemná Řásnovka'. These novels are also non-scout ones, picturing independent life of youths. On the other hand, in a second large group of his novels, a 'group hero' novels, the plot is based on stories of some organized group of youths, with less individual psychology and more action and adventures. The heroes are boy scouts or independent clubbists.

Homoerotic elements in his novels
Some critics argued that Foglar's novels are crammed with covert homoerotic desire, or that the author himself was gay. Foglar was strongly influenced by German Wandervogel romanticism more than the ideas of British scout movement (which emerged in Czech Lands during the WWI). Wandervogel movement itself had some elements of male eroticism. Most of Foglar's novels include close friendships between two youths, with some exceptions in relation to the 'group-hero' novels like 'Rychlé šípy' Club and 'Devadesátka'.

Foglar's novels are set in a prevalently male world, where women are often irrelevant (old grannies or small girls, often without names). This homosociality was very common in literature of the period, regardless of the sexual orientation of the author. Besides, there are also a few strong female characters in his books, and especially in his comic series "Rychlé šípy". Foglar did have a few serious (though eventually unsuccessful) love affairs with women.

Books
Note: the list is incomplete.
 * Rychlé šípy
 * Hoši od Bobří řeky ("Boys from the Beavers' river")
 * Přístav volá ("The port is calling")
 * Když duben přichází ("When April is coming")
 * Pod junáckou vlajkou ("Under the Scouts' flag")
 * Devadesátka pokračuje ("The Ninety goes on")
 * Záhada hlavolamu ("Mystery of the conundrum"), the mechanical puzzle Hedgehog in the Cage plays a central role in the book
 * Stínadla se bouří ("The Shades are revolting")
 * Tajemství velkého Vonta ("Secret of the High Vont")
 * Strach nad Bobří řekou ("Fear above the Beavers' river")
 * Chata v jezerní kotlině ("The log-house in the lake basin")
 * Tábor smůly ("The camp of ill luck")
 * Tajemná Řásnovka ("Mysterious Řásnovka")
 * Boj o první místo ("A fight over the first place")
 * Historie svorné sedmy ("History of the harmonious seven")
 * Poklad Černého delfína ("Treasure of the Black dolphin")
 * Kronika ztracené stopy ("Chronicle of the lost track")
 * Náš oddíl ("Our troop")
 * Dobrodružství v zemi nikoho ("An adventure in the no-man's land")
 * Modrá rokle ("The Blue gorge")
 * Jestřábe, vypravuj ("Tell us the story, Goshawk")
 * Život v poklusu ("A life in a trot")

Some of his books were published in Slovakia, Hungary, Poland and Germany. "Boys from the Beavers' river" was also published in Esperanto.

title: Jaroslav Foglar


text:
Talk:Jaroslav Foglar

Books
Please add to the list of his books.

Would you mind translating some of the titles? olivier 15:07 Oct 26, 2002 (UTC)

 * I think that translating "Stínadla" as Shades is error. Stínadla means part of city, where in middleage were prisoners hanged and beheaded. Stít=behead. Robin_WH 22:26 Jul 23, 2008 (CET) —Preceding unsigned comment added by 89.102.179.75 (talk) 20:26, 23 July 2008 (UTC)

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title: Talk:Jaroslav Foglar


text:
Talk:Polarization (waves)

Reverted lede
I reverted recent edits to the lede. See the sections above, and. Electromagnetic waves are not always transverse, and polarization is not a property only of transverse waves. The statement "Waves that oscillate only in a single plane are referred to as polarized, while ones that oscillate in multiple planes are said to be unpolarized." is badly wrong. Circularly polarized waves do not oscillate in a single plane, and they are not unpolarized. --Srleffler (talk) 02:55, 7 February 2017 (UTC)

 * Well, I know about the circularly polarized waves, but I felt that they're sort of a special case, and it can be argued that it is still a single plane at any given moment. I don't mind your revert, as changes by Chetvorno and myself probably weren't thought out too well. Still, I feel that much of the lead is needlessly vague, particularly the first sentence, which is supposed to be definition: parameter ... that specifies the geometrical orientation of the oscillation is not terribly informative; and polarization is hardly a "parameter" – I'd expect that you could assign a single numerical value to a parameter, but polarization is too complex for that. No such user (talk) 08:15, 7 February 2017 (UTC)
 * Circular polarization is not a special case, and is as fundamental as linear polarization is. You can describe any polarization as a superposition of left and right circular polarization. Describing it as a single plane at any given moment is not a good way to think about it.
 * The wording can probably be improved but it's hard. The lede for this article has to walk a tightrope between presenting a complex subject accurately, and presenting it simply enough that everyone can understand. It's probably best to discuss ideas for changes here first.--Srleffler (talk) 02:03, 8 February 2017 (UTC)

 * I agree, my edits weren't well thought out and I don't mind the revert; "drive by" editing is always a bad idea. However like No such user I would like to see the introduction be clearer for general readers.  I have no argument with the lead sentence. but I would like to see the concepts of longitudinal and transverse waves appear in the introduction, because I think there should be a statement that only transverse waves have polarization.    While the plane containing the electric and magnetic fields is not always perpendicular to the wave vector, electromagnetic waves are classified as "transverse waves"; the fields cannot be parallel to the wave vector so they always have "transverse" components.  In contrast in the most common type of longitudinal wave, sound waves in fluids, the displacement is always in the direction of the wave vector so it has no degrees of freedom, hence there can't be different polarization states.   Many sources state that polarization only occurs in transverse waves:, , , ,   -- Chetvorno TALK 11:10, 9 February 2017 (UTC)
 * Oops, thanks for reverting my accidental page blanking, No such user :) -- Chetvorno TALK 13:08, 9 February 2017 (UTC)
 * Rewrote lead to be consistent with the above sources. -- Chetvorno TALK 18:47, 20 February 2017 (UTC)

Transverse EM-waves
What is the factor Q in this part of the article? 2A02:A463:2848:1:B877:7C1B:4DDD:B31C (talk) 14:36, 18 August 2023 (UTC)

First person plural language
Usually, Wikipedia articles read like they are really an article but this article reads like it's a paper, with lots of uses of "we", like "as we have shown". Is it important, should this not be in this case "as shown above", etc.? Dan Dart (talk) 16:32, 27 September 2023 (UTC)

 * Yes, see WP:PRONOUN. Articles should not be written in first-person.--Srleffler (talk) 04:23, 28 September 2023 (UTC)

title: Talk:Polarization (waves)


text:
Marcus Licinius Crassus

Marcus Licinius Crassus (115 – 53 BC) was a Roman general and statesman who played a key role in the transformation of the Roman Republic into the Roman Empire. He is often called "the richest man in Rome".

Crassus began his public career as a military commander under Lucius Cornelius Sulla during his civil war. Following Sulla's assumption of the dictatorship, Crassus amassed an enormous fortune through property speculation. Crassus rose to political prominence following his victory over the slave revolt led by Spartacus, sharing the consulship with his rival Pompey the Great.

A political and financial patron of Julius Caesar, Crassus joined Caesar and Pompey in the unofficial political alliance known as the First Triumvirate. Together, the three men dominated the Roman political system, but the alliance did not last long, due to the ambitions, egos, and jealousies of the three men. While Caesar and Crassus were lifelong allies, Crassus and Pompey disliked each other and Pompey grew increasingly envious of Caesar's spectacular successes in the Gallic Wars. The alliance was restabilized at the Luca Conference in 56 BC, after which Crassus and Pompey again served jointly as consuls. Following his second consulship, Crassus was appointed as the governor of Roman Syria. Crassus used Syria as the launchpad for a military campaign against the Parthian Empire, Rome's long-time eastern enemy. Crassus' campaign was a disastrous failure, ending in his defeat at the Battle of Carrhae and death in its aftermath.

Crassus' death permanently unraveled the alliance between Caesar and Pompey, since his political influence and wealth had been a counterbalance to the two greater militarists. Within four years of Crassus' death, Caesar crossed the Rubicon and began a civil war against Pompey and the optimates.

Family and background
Marcus Licinius Crassus was a member of the gens Licinia, an old and highly respected plebeian family in Rome. He was the second of three sons born to the eminent senator and vir triumphalis Publius Licinius Crassus (consul 95 BC, censor 89 BC). This line was not descended from the wealthy Crassi Divites, although often assumed to be. The eldest brother, Publius (born c. 116 BC), died shortly before the Italic War, and Crassus' father and younger brother were either slain or took their own lives in Rome, in winter 87–86 BC, when being hunted down by the supporters of Gaius Marius, following their victory in the Bellum Octavianum. Crassus had the unusual distinction of marrying his wife Tertulla after she had been widowed by his brother.

There were three main branches of the house of the Licinii Crassi in the 2nd and 1st centuries BC, and many mistakes in identifications and lines have arisen owing to the uniformity of Roman nomenclature, erroneous modern suppositions, and the unevenness of information across the generations. In addition, the Dives cognomen of the Crassi Divites means rich or wealthy, and since Marcus Crassus, the subject here, was renowned for his enormous wealth, this has contributed to hasty assumptions that his family belonged to the Divites. But no ancient source accords him or his father the Dives cognomen; Plutarch says his great wealth was acquired rather than inherited, and that he was raised in modest circumstances.

Crassus' grandfather of the same name, Marcus Licinius Crassus (praetor c. 126 BC), was facetiously given the Greek nickname Agelastus (the unlaughing or grim) by his contemporary Gaius Lucilius, the inventor of Roman satire, who asserted that he smiled once in his whole life. This grandfather was son of Publius Licinius Crassus. The latter's brother, Gaius Licinius Crassus (consul 168 BC), produced the third line of Licinii Crassi of the period, the most famous of whom was Lucius Licinius Crassus, the greatest Roman orator before Cicero and the latter's childhood hero and model. Marcus Crassus was also a talented orator and one of the most energetic and active advocates of his time.

Youth and the First Civil War
After the Marian purges and the subsequent sudden death of Gaius Marius, the surviving consul Lucius Cornelius Cinna (father-in-law of Julius Caesar) imposed proscriptions on those surviving Roman senators and equestrians who had supported Lucius Cornelius Sulla in his 88 BC march on Rome and overthrow of the traditional Roman political arrangements.

Cinna's proscription forced Crassus to flee to Hispania. He stayed in Spain from 87 to 84 BC. Here, he recruited 2,500 men (an understrength legion) from his father's clients settled in the area. Crassus used his army to extort money from the local cities to pay for his campaigns, even being accused of sacking Malaca. After Cinna's death in 84 BC, Crassus went to the Roman province of Africa and joined Metellus Pius, one of Sulla's closest allies, but did not stay there for long because of disagreements with Metellus. He sailed his army to Greece and joined Sulla, "with whom he stood in a position of special honor." During Sulla's civil war, Crassus and Pompey fought a battle in the plain of Spoletium (Spoleto), killed about 3,000 of the men of Papirius Carbo, the leader of the Marian forces, and besieged Carrinas, a Marian commander.

During the decisive Battle of the Colline Gate, Crassus commanded the right flank of Sulla's army. After almost a day of fighting, the battle was going poorly for Sulla; his own center was being pushed back and was on the verge of collapse when he got word from Crassus that he had comprehensively crushed the enemy before him. Crassus wanted to know whether Sulla needed assistance, or whether his men could retire. Sulla told him to advance on the enemy's center, and used the news of Crassus' success to stiffen the resolve of his own troops. By the following morning, the battle was over, and the Sullan army emerged victorious, making Sulla the master of Rome. Sulla's victory, and Crassus' contribution to it, put Crassus in a key position. Sulla was as loyal to his allies as he was cruel towards his enemies, and Crassus had been a very loyal ally.

Rise to power and wealth
Marcus Licinius Crassus' next concern was to rebuild the fortunes of his family, which had been confiscated during the Marian-Cinnan proscriptions. Sulla's proscriptions, in which the property of his victims was cheaply auctioned off, found one of the greatest acquirers of this type of property in Crassus: indeed, Sulla was especially supportive of this, because he wished to spread the blame as much as possible among those unscrupulous enough to do so. Sulla's proscriptions ensured that his survivors would recoup their lost fortunes from the fortunes of wealthy adherents to Gaius Marius or Lucius Cornelius Cinna. Proscriptions meant that their political enemies lost their fortunes and their lives; that their female relatives (notably, widows and widowed daughters) were forbidden to marry, remarry or remain married; and that, in some cases, their families' hopes of rebuilding their fortunes and political significance were destroyed. Crassus is said to have made part of his money from proscriptions, notably the proscription of one man whose name was not initially on the list of those proscribed but was added by Crassus, who coveted the man's fortune. Crassus' wealth is estimated by Pliny at approximately 200 million sesterces. Plutarch, in his Life of Crassus, says the wealth of Crassus increased from less than 300 talents at first, to 7,100 talents. This represented 229 tonnes of silver, worth about US$167.4 million at August 2023 silver prices, accounted right before his Parthian expedition, most of which Plutarch declares Crassus got "by fire and war, making the public calamities his greatest source of revenue."

Some of Crassus' wealth was acquired conventionally, through slave trafficking, production from silver mines, and speculative real estate purchases. Crassus bought property that was confiscated in proscriptions and by notoriously purchasing burnt and collapsed buildings. Plutarch wrote that, observing how frequent such occurrences were, he bought slaves "who were architects and builders." When he had over 500 slaves, he bought houses that had burnt and the adjacent ones "because their owners would let go at a trifling price." He bought "the largest part of Rome" in this way, buying them on the cheap and rebuilding them with slave labor.

The first ever Roman fire brigade was created by Crassus. Fires were almost a daily occurrence in Rome, and Crassus took advantage of the fact that Rome had no fire department, by creating his own brigade—500 men strong—which rushed to burning buildings at the first cry of alarm. Upon arriving at the scene, however, the firefighters did nothing while Crassus offered to buy the burning building from the distressed property owner, at a miserable price. If the owner agreed to sell the property, his men would put out the fire; if the owner refused, then they would simply let the structure burn to the ground. After buying many properties this way, he rebuilt them, and often leased the properties to their original owners or new tenants.

Crassus befriended Licinia, a Vestal Virgin, whose valuable property he coveted. Plutarch says "And yet, when he was further on in years, he was accused of criminal intimacy with Licinia, one of the vestal virgins, and Licinia was formally prosecuted by a certain Plotius. Now, Licinia was the owner of a pleasant villa in the suburbs, which Crassus wished to get at a low price, and it was for this reason that he was forever hovering about the woman and paying his court to her, until he fell under the abominable suspicion. And, in a way, it was his avarice that absolved him from the charge of corrupting the vestal, and he was acquitted by the judges. But he did not let Licinia go until he had acquired her property."

Despite his great wealth, Crassus is said to have avoided excess and luxury at home. Family meals were simple, and entertaining was generous but not ostentatious; Crassus chose his companions during leisure hours on the basis of personal friendship as well as political utility. Although the Crassi, as noble plebeians, would have displayed ancestral images in their atrium, they did not lay claim to a fictionalized genealogy that presumed divine or legendary ancestors, a practice not uncommon among the Roman nobility.

After rebuilding his fortune, Crassus' next concern was his political career. As a wealthy man in Rome, an adherent of Sulla, and a man who hailed from a line of consuls and praetors, Crassus' political future was apparently assured. His problem was that, despite his military successes, he was eclipsed by his contemporary Pompey the Great. Crassus' rivalry with Pompey and his envy of Pompey's triumph would influence his subsequent career.

Crassus and Spartacus
Crassus was elected praetor in 73 BC and pursued the cursus honorum.

During the Third Servile War, or Spartacus' revolt (73–71 BC), Crassus offered to equip, train, and lead new troops at his own expense, after several legions had been defeated and their commanders killed in battle. Crassus was sent into battle against Spartacus by the Senate. At first, he had trouble both in anticipating Spartacus' moves and in inspiring his army to strengthen their morale. When a segment of his army fled from battle, abandoning their weapons, Crassus revived the ancient practice of decimation – i.e. executing one out of every ten men, with the victims selected by drawing lots. Plutarch reports that "many things horrible and dreadful to see" occurred during the infliction of punishment, which was witnessed by the rest of Crassus' army. Nevertheless, according to Appian, the troops' fighting spirit improved dramatically thereafter, since Crassus had demonstrated that "he was more dangerous to them than the enemy."

Afterwards, when Spartacus retreated to the Bruttium peninsula in the southwest of Italy, Crassus tried to pen up the slave armies by building a ditch and a rampart across the peninsula of Rhegium in Bruttium, "from sea to sea." Despite this remarkable feat, Spartacus and part of his army still managed to break out. On the night of a heavy snowstorm, they sneaked through Crassus' lines and made a bridge of dirt and tree branches over the ditch, thus escaping.

Some time later, when the Roman armies led by Pompey and Varro Lucullus were recalled to Italy in support of Crassus, Spartacus decided to fight rather than find himself and his followers trapped between three armies, two of them returning from overseas action. In this last battle, the battle of the Silarius river, Crassus gained a decisive victory, and captured six thousand slaves alive. During the fighting, Spartacus attempted to personally kill Crassus, slaughtering his way toward the general's position, but he succeeded only in killing two of the centurions guarding Crassus. Spartacus himself is believed to have been killed in the battle, although his body was never recovered. The six thousand captured slaves were crucified along the Via Appia by Crassus' orders. At his command, their bodies were not taken down afterwards, but remained rotting along Rome's principal route to the south. This was intended as an abject lesson to anyone who might think of rebelling against Rome in the future, particularly of slave insurrections against their owners and masters, the Roman citizens.

Crassus effectively ended the Third Servile War in 71 BC. In Plutarch's account, Crassus "had written to the Senate that they must summon Lucullus from Thrace and Pompey from Spain, but he was sorry now that he had done so, and was eager to bring the war to an end before those generals came. He knew that the success would be ascribed to the one who came up with assistance, and not to himself." He decided to attack a splinter group of rebels, and after this, Spartacus withdrew to the mountains. Pompey had arrived from Hispania with his veterans and was sent to provide reinforcements. Crassus hurried to seek the final battle, which he won. Pompey arrived in time to deal with the disorganized and defeated fugitives, writing to the Senate that "indeed, Crassus had conquered the slaves, but that he himself had extirpated the war." "Crassus, for all his self-approval, did not venture to ask for the major triumph, and it was thought ignoble and mean in him to celebrate even the minor triumph on foot, called the ovation," nor did he wish to be honored for subduing slaves.

In Plutarch's account, Pompey was asked to stand for the consulship. Crassus wanted to become his colleague and asked Pompey for his assistance. As said in the Life of Crassus, "Pompey received his request gladly (for he was desirous of having Crassus, in some way or other, always in debt to him for some favor), eagerly promoted his candidature, and finally said in a speech to the assembly that he should be no less grateful to them for the colleague than for the office which he desired." However, in office, they did not remain friendly. They "differed on almost every measure, and by their contentiousness, rendered their consulship barren politically and without achievement." Crassus displayed his wealth by realizing public sacrifices to Hercules, entertaining the populace at 10,000 tables and distributing sufficient grain to last each family three months, an act that had the additional ends of performing a previously made religious vow of a tithe to the demigod Hercules and also to gain support among the members of the popular party.

In Appian's account, when Crassus ended the rebellion, there was a contention over honors between him and Pompey. Neither men dismissed their armies, with both being candidates for the consulship. Crassus had been praetor as the law of Sulla required. Pompey had been neither praetor nor quaestor, and was only 34 years old, but he had promised the plebeian tribunes to restore much of their power, that had been taken away by Sulla's constitutional reforms. Even when they were both chosen consuls, they did not dismiss their armies stationed near the city. Pompey said that he was awaiting the return of Metellus for his Spanish triumph; Crassus said that Pompey ought to dismiss his army first. In the end, Crassus yielded first, offering Pompey his hand.

First Triumvirate-Alliance with Pompey and Caesar
In 65 BC, Crassus was elected censor with another conservative, Quintus Lutatius Catulus Capitolinus, himself son of a consul. During that decade, Crassus was Julius Caesar's patron in all but name, financing Caesar's successful election to become pontifex maximus. Caesar had formerly been the priest of Jupiter, or flamen dialis, but had been deprived of office by Sulla. Crassus also supported Caesar's efforts to win command of military campaigns. Caesar's mediation between Crassus and Pompey led to the creation of the First Triumvirate in 60 BC, consisting of Crassus, Pompey, and Caesar (who became consul in 59 BC). This coalition would last until Crassus' death. In 54 BC, Crassus looted the Jewish Temple treasury. In 55 BC, after the Triumvirate met at the Luca Conference in 56 BC, Crassus was again consul with Pompey, and a law was passed assigning the provinces of the two Hispanias and Syria to Pompey and Crassus, respectively, for five years.

Syrian governorship and death
Crassus received Syria as his province, which promised to be an inexhaustible source of wealth. It might have been, had he not also sought military glory and crossed the Euphrates in an attempt to conquer Parthia. Crassus attacked Parthia not only because of its great source of riches, but because of a desire to match the military victories of Pompey and Caesar. The king of Armenia, Artavasdes II, offered Crassus the aid of nearly 40,000 troops (10,000 cataphracts and 30,000 infantrymen) on the condition that Crassus invade through Armenia so that the king could not only maintain the upkeep of his own troops but also provide a safer route for his men and Crassus. Crassus refused, and chose the more direct route by crossing the Euphrates, as he had done in his successful campaign in the previous year. Crassus received directions from the Osroene chieftain Ariamnes, who had previously assisted Pompey in his eastern campaigns. Ariamnes was in the pay of the Parthians and urged Crassus to attack at once, falsely stating that the Parthians were weak and disorganized. He then led Crassus' army into desolate desert, far from any water. In 53 BC, at the Battle of Carrhae (modern Harran, in Turkey), Crassus' legions were defeated by a numerically inferior Parthian force. Crassus' legions were primarily heavy infantry, but were not prepared for the type of swift, cavalry-and-arrow attack in which Parthian troops were particularly adept. The Parthian horse archers devastated the unprepared Romans with hit-and-run techniques and feigned retreats with the ability to shoot as well backwards as they could forwards. Crassus refused his quaestor Gaius Cassius Longinus' plans to reconstitute the Roman battle line, and remained in the testudo formation to protect his flanks until the Parthians eventually ran out of arrows. However, the Parthians had stationed camels carrying arrows to allow their archers to continually reload and relentlessly barrage the Romans until dusk. Despite taking severe casualties, the Romans successfully retreated to Carrhae, forced to leave many wounded behind to be later slaughtered by the Parthians. Subsequently, Crassus' men, being near mutiny, demanded he parley with the Parthians, who had offered to meet with him. Crassus, despondent at the death of his son Publius in the battle, finally agreed to meet the Parthian general Surena. However, when Crassus mounted a horse to ride to the Parthian camp for a peace negotiation, his junior officer Octavius suspected a Parthian trap and grabbed Crassus' horse by the bridle, instigating a sudden fight with the Parthians that left the Roman party dead, including Crassus. A story later emerged to the effect that, after Crassus' death, the Parthians poured molten gold into his mouth in a symbolic mockery of his thirst for wealth.

The account given in Plutarch's biography of Crassus also mentions that, during the feasting and revelry in the wedding ceremony of Artavasdes' sister to the Parthian king Orodes II's son and heir Pacorus in the Armenian capital of Artashat, Crassus' head was brought to Orodes II. Both kings were enjoying a performance of Euripides' Greek tragedy The Bacchae when a certain actor of the royal court, named Jason of Tralles, took the head and sang the following verses (also from the Bacchae):

"We bring from the mountain A tendril fresh-cut to the palace A wonderful prey." Crassus' head was thus used in place of a prop head representing Pentheus and carried by the character of Agave.

Also according to Plutarch, a final mockery was made ridiculing the memory of Crassus, by dressing up a Roman prisoner, Caius Paccianus, who resembled him in appearance, in women's clothing, calling him "Crassus" and "imperator," and leading him in a spectacular show of a final, mock "triumphal procession," putting to ridiculous use the traditional symbols of Roman triumph and authority.

Chronology

 * 115 BC – Crassus is born in Rome, second of three sons of Publius Licinius Crassus (cos. 97 BC, cens. 89 BC);
 * 97 BC – Father is consul of Rome;
 * 87 BC – Crassus flees to Hispania from Marian forces;
 * 84 BC – Joins Sulla against Marius;
 * 82 BC – Commands the victorious right wing of Sulla's army at the Colline Gate, the decisive battle of the civil war, fought on Kalends of November;
 * 78 BC – Sulla dies in the spring;
 * 73 BC – Revolt of Spartacus, probable year Crassus was praetor (it's possible for him to have done so between 75 and 73 BC);
 * 72 BC – Crassus is given special command of the war against Spartacus following the ignominious defeats of both consuls;
 * 71 BC – Crassus destroys the remaining slave armies in the spring, and is elected consul in the summer;
 * 70 BC – Consulship of Crassus and Pompey;
 * 65 BC – Crassus is censor with Quintus Lutatius Catulus;
 * 63 BC – Catiline conspiracy;
 * 59 BC – First Triumvirate formed, with Caesar as consul;
 * 56 BC – Conference at Lucca;
 * 55 BC – Second consulship of Crassus and Pompey, with Crassus leaving for Syria in November;
 * 54 BC – Campaign against the Parthians;
 * 53 BC – Crassus dies in the Battle of Carrhae.

Literature

 * Crassus is cited as an example of greed in Dante Alighieri's Divine Comedy
 * Crassus is a major character in Howard Fast's 1951 novel Spartacus.
 * Crassus is a major character in the 1956 Alfred Duggan novel Winter Quarters. The novel follows two fictional Gallic nobles who join Julius Caesar's cavalry and then find their way into the service of Marcus' son, Publius Licinius Crassus, in Gaul. The characters eventually become clients of Publius Crassus, and, by extension, his father Marcus. The second half of the novel is related by its Gallic narrator from within the ranks of Crassus' doomed army en route to do battle with Parthia. The book depicts an overconfident and militarily incompetent Crassus up to the moment of his death.
 * Crassus is a major character in the 1992 novel Arms of Nemesis by Steven Saylor. He is portrayed as the cousin and patron of Lucius Licinius, the investigation of whose murder forms the basis of the novel. He also has minor appearances in Roman Blood and Catalina's Riddle.
 * In David Drake's Ranks of Bronze (1986), the Lost Legion is the major participant, although Crassus himself has been killed before the book begins.
 * Crassus is a major character in Conn Iggulden's Emperor series.
 * The story of the battle of Carrhae is the centerpiece of Ben Kane's novel The Forgotten Legion (2008). Crassus is depicted as a vain man with poor military judgment.
 * Crassus is a major character in Robert Harris' novel Lustrum (published as Conspirata in the USA), the sequel to Imperium, which both chronicle the career of Marcus Tullius Cicero.
 * Crassus is a major character in the novels Fortune's Favourites and Caesar's Women by Colleen McCullough. He is portrayed as a brave but mediocre general, a brilliant financier, and a true friend of Caesar.

Ballet

 * Crassus (Russian: Красс) has a principal role in Aram Khachaturian's 1956 ballet Spartacus.

Drama
Film
 * Crassus is a principal character in the 1960 film Spartacus, played by actor Laurence Olivier. The film is based on Howard Fast's 1951 novel of the same name.
 * Crassus is the antagonist in the 1962 film The Slave, played by actor Claudio Gora.
 * A highly fictionalized version of Crassus called Marcus Crassius is an enemy figure in the film Amazons and Gladiators (2001), played by Patrick Bergin. They mention his defeating Spartacus and that Caesar exiles him due to his popularity to a poor province, where he's very cruel to the populace; he conquers the Amazons, under Queen Zenobia (who apparently rules a tribe of Amazons in the same province, Pannae). In this film, he is killed by a young girl whose family he killed.
 * A character named Hamilton Crassus III portrayed by Jon Voight in Francis Ford Coppola's 2024 sci-fi epic film Megalopolis, is based on Marcus Licinius Crassus. The film is a modern take of the Catiline Conspiracy set in an imagined futuristic Modern America.

Television
 * Crassus is a principal character in the 2004 TV film Spartacus, played by actor Angus Macfadyen.
 * Crassus appears in a 3rd season episode of Xena: Warrior Princess, where he is beheaded in the Colosseum.
 * He is portrayed by Simon Merrells in Spartacus: War of the Damned as the main antagonist. Unlike in Alfred Duggan's novel, he is portrayed as a brilliant military tactician.
 * Crassus was also mentioned in the fifth series of Horrible Histories, with a song named "Minted" dedicated to his life parodying Dizzie Rascal's Bonkers sung by Simon Farnaby.
 * Crassus appears in the second season of the Netflix original series Roman Empire.

Music

 * Crassus, along with Palene, is one of the two narrators in Jeff Wayne's Musical Version of Spartacus. He is played by Anthony Hopkins.

Video games

 * Crassus appears as one of the villains in Spartan: Total Warrior.
 * Crassus makes an appearance as a Great Merchant in Sid Meier's Civilization V and Sid Meier's Civilization VI.
 * Crassus appears as one of the hero centurions in some of the campaign missions in Praetorians. He would later be killed in the campaign mission depicting the battle of Carrhae.

title: Marcus Licinius Crassus


text:
Buffer solution

A buffer solution is a solution where the pH does not change significantly on dilution or if an acid or base is added at constant temperature. Its pH changes very little when a small amount of strong acid or base is added to it. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical applications. In nature, there are many living systems that use buffering for pH regulation. For example, the bicarbonate buffering system is used to regulate the pH of blood, and bicarbonate also acts as a buffer in the ocean.

Principles of buffering
Buffer solutions resist pH change because of a chemical equilibrium between the weak acid HA and its conjugate base A−:

When some strong acid is added to an equilibrium mixture of the weak acid and its conjugate base, hydrogen ions (H+) are added, and the equilibrium is shifted to the left, in accordance with Le Chatelier's principle. Because of this, the hydrogen ion concentration increases by less than the amount expected for the quantity of strong acid added. Similarly, if strong alkali is added to the mixture, the hydrogen ion concentration decreases by less than the amount expected for the quantity of alkali added. In Figure 1, the effect is illustrated by the simulated titration of a weak acid with pKa = 4.7. The relative concentration of undissociated acid is shown in blue, and of its conjugate base in red. The pH changes relatively slowly in the buffer region, pH = pKa ± 1, centered at pH = 4.7, where [HA] = [A−]. The hydrogen ion concentration decreases by less than the amount expected because most of the added hydroxide ion is consumed in the reaction

and only a little is consumed in the neutralization reaction (which is the reaction that results in an increase in pH)

Once the acid is more than 95% deprotonated, the pH rises rapidly because most of the added alkali is consumed in the neutralization reaction.

Buffer capacity
Buffer capacity is a quantitative measure of the resistance to change of pH of a solution containing a buffering agent with respect to a change of acid or alkali concentration. It can be defined as follows: $$\beta = \frac{dC_b}{d(\mathrm{pH})},$$ where $$dC_b$$ is an infinitesimal amount of added base, or $$\beta = -\frac{dC_a}{d(\mathrm{pH})},$$ where $$dC_a$$ is an infinitesimal amount of added acid. pH is defined as −log10[H+], and d(pH) is an infinitesimal change in pH.

With either definition the buffer capacity for a weak acid HA with dissociation constant Ka can be expressed as

where [H+] is the concentration of hydrogen ions, and $$T_\text{HA}$$ is the total concentration of added acid. Kw is the equilibrium constant for self-ionization of water, equal to 1.0. Note that in solution H+ exists as the hydronium ion H3O+, and further aquation of the hydronium ion has negligible effect on the dissociation equilibrium, except at very high acid concentration.

This equation shows that there are three regions of raised buffer capacity (see figure 2).
 * In the central region of the curve (coloured green on the plot), the second term is dominant, and Buffer capacity rises to a local maximum at pH = pKa. The height of this peak depends on the value of pKa. Buffer capacity is negligible when the concentration [HA] of buffering agent is very small and increases with increasing concentration of the buffering agent. Some authors show only this region in graphs of buffer capacity.  Buffer capacity falls to 33% of the maximum value at pH = pKa ± 1, to 10% at pH = pKa ± 1.5 and to 1% at pH = pKa ± 2. For this reason the most useful range is approximately pKa ± 1. When choosing a buffer for use at a specific pH, it should have a pKa value as close as possible to that pH.
 * With strongly acidic solutions, pH less than about 2 (coloured red on the plot), the first term in the equation dominates, and buffer capacity rises exponentially with decreasing pH: $$\beta \approx 10^{-\mathrm{pH}}.$$ This results from the fact that the second and third terms become negligible at very low pH. This term is independent of the presence or absence of a buffering agent.
 * With strongly alkaline solutions, pH more than about 12 (coloured blue on the plot), the third term in the equation dominates, and buffer capacity rises exponentially with increasing pH: $$\beta \approx 10^{\mathrm{pH} - \mathrm{p}K_\text{w}}.$$ This results from the fact that the first and second terms become negligible at very high pH. This term is also independent of the presence or absence of a buffering agent.

Applications of buffers
The pH of a solution containing a buffering agent can only vary within a narrow range, regardless of what else may be present in the solution. In biological systems this is an essential condition for enzymes to function correctly. For example, in human blood a mixture of carbonic acid (H$2$CO$3$) and bicarbonate (HCO$− 3$) is present in the plasma fraction; this constitutes the major mechanism for maintaining the pH of blood between 7.35 and 7.45. Outside this narrow range (7.40 ± 0.05 pH unit), acidosis and alkalosis metabolic conditions rapidly develop, ultimately leading to death if the correct buffering capacity is not rapidly restored.

If the pH value of a solution rises or falls too much, the effectiveness of an enzyme decreases in a process, known as denaturation, which is usually irreversible. The majority of biological samples that are used in research are kept in a buffer solution, often phosphate buffered saline (PBS) at pH 7.4.

In industry, buffering agents are used in fermentation processes and in setting the correct conditions for dyes used in colouring fabrics. They are also used in chemical analysis and calibration of pH meters.

Simple buffering agents

 * {| class="wikitable"

! Buffering agent !! pKa !! Useful pH range For buffers in acid regions, the pH may be adjusted to a desired value by adding a strong acid such as hydrochloric acid to the particular buffering agent. For alkaline buffers, a strong base such as sodium hydroxide may be added. Alternatively, a buffer mixture can be made from a mixture of an acid and its conjugate base. For example, an acetate buffer can be made from a mixture of acetic acid and sodium acetate. Similarly, an alkaline buffer can be made from a mixture of the base and its conjugate acid.
 * Citric acid || 3.13, 4.76, 6.40 || 2.1–7.4
 * Acetic acid || 4.8 || 3.8–5.8
 * KH2PO4 || 7.2 || 6.2–8.2
 * CHES || 9.3 || 8.3–10.3
 * Borate || 9.24 || 8.25–10.25
 * }
 * CHES || 9.3 || 8.3–10.3
 * Borate || 9.24 || 8.25–10.25
 * }
 * Borate || 9.24 || 8.25–10.25
 * }

"Universal" buffer mixtures
By combining substances with pKa values differing by only two or less and adjusting the pH, a wide range of buffers can be obtained. Citric acid is a useful component of a buffer mixture because it has three pKa values, separated by less than two. The buffer range can be extended by adding other buffering agents. The following mixtures (McIlvaine's buffer solutions) have a buffer range of pH 3 to 8.
 * {| class="wikitable"

! 0.2 M Na2HPO4 (mL) ! 0.1 M citric acid (mL) ! pH
 * 20.55
 * 79.45
 * style="background:#ff0000; color:white" | 3.0
 * 38.55
 * 61.45
 * style="background:#ff7777; color:white" |4.0
 * 51.50
 * 48.50
 * style="background:#ff7700;" | 5.0
 * 63.15
 * 36.85
 * style="background:#ffff00;" |6.0
 * 82.35
 * 17.65
 * style="background:#007777; color:white" | 7.0
 * 97.25
 * 2.75
 * style="background:#0077ff; color:white" | 8.0
 * }
 * style="background:#007777; color:white" | 7.0
 * 97.25
 * 2.75
 * style="background:#0077ff; color:white" | 8.0
 * }
 * }

A mixture containing citric acid, monopotassium phosphate, boric acid, and diethyl barbituric acid can be made to cover the pH range 2.6 to 12.

Other universal buffers are the Carmody buffer and the Britton–Robinson buffer, developed in 1931.

Common buffer compounds used in biology
For effective range see Buffer capacity, above. Also see Good's buffers for the historic design principles and favourable properties of these buffer substances in biochemical applications.

Monoprotic acids
First write down the equilibrium expression

This shows that when the acid dissociates, equal amounts of hydrogen ion and anion are produced. The equilibrium concentrations of these three components can be calculated in an ICE table (ICE standing for "initial, change, equilibrium").
 * {| class="wikitable"

! ! [HA] !! [A−] !! [H+] ! I ! C ! E The first row, labelled I, lists the initial conditions: the concentration of acid is C0, initially undissociated, so the concentrations of A− and H+ would be zero; y is the initial concentration of added strong acid, such as hydrochloric acid. If strong alkali, such as sodium hydroxide, is added, then y will have a negative sign because alkali removes hydrogen ions from the solution. The second row, labelled C for "change", specifies the changes that occur when the acid dissociates. The acid concentration decreases by an amount −x, and the concentrations of A− and H+ both increase by an amount +x. This follows from the equilibrium expression. The third row, labelled E for "equilibrium", adds together the first two rows and shows the concentrations at equilibrium.
 * + ICE table for a monoprotic acid
 * C0 || 0 || y
 * −x || x || x
 * C0 − x || x || x + y
 * }

To find x, use the formula for the equilibrium constant in terms of concentrations:

Substitute the concentrations with the values found in the last row of the ICE table: $$K_\text{a} = \frac{x(x + y)}{C_0 - x}.$$

Simplify to $$x^2 + (K_\text{a} + y) x - K_\text{a} C_0 = 0.$$

With specific values for C0, Ka and y, this equation can be solved for x. Assuming that pH = −log10[H+], the pH can be calculated as pH = −log10(x + y).

Polyprotic acids

Polyprotic acids are acids that can lose more than one proton. The constant for dissociation of the first proton may be denoted as Ka1, and the constants for dissociation of successive protons as Ka2, etc. Citric acid is an example of a polyprotic acid H3A, as it can lose three protons.
 * {| class="wikitable" style="width: 230px;

! |Equilibrium!!Citric acid
 * + Stepwise dissociation constants
 * H3A H2A− + H+||pKa1 = 3.13
 * H2A− HA2− + H+|| pKa2 = 4.76
 * HA2− A3− + H+|| pKa3 = 6.40
 * }
 * HA2− A3− + H+|| pKa3 = 6.40
 * }
 * }

When the difference between successive pKa values is less than about 3, there is overlap between the pH range of existence of the species in equilibrium. The smaller the difference, the more the overlap. In the case of citric acid, the overlap is extensive and solutions of citric acid are buffered over the whole range of pH 2.5 to 7.5.

Calculation of the pH with a polyprotic acid requires a speciation calculation to be performed. In the case of citric acid, this entails the solution of the two equations of mass balance:

CA is the analytical concentration of the acid, CH is the analytical concentration of added hydrogen ions, βq are the cumulative association constants. Kw is the constant for self-ionization of water. There are two non-linear simultaneous equations in two unknown quantities [A3−] and [H+]. Many computer programs are available to do this calculation. The speciation diagram for citric acid was produced with the program HySS.

N.B. The numbering of cumulative, overall constants is the reverse of the numbering of the stepwise, dissociation constants.
 * {| class="wikitable"

! Equilibrium!! Relationship Cumulative association constants are used in general-purpose computer programs such as the one used to obtain the speciation diagram above.
 * + Relationship between cumulative association constant (β) values and stepwise dissociation constant (K) values for a tribasic acid.
 * A3− + H+ AH2+||Log β1= pka3
 * A3− + 2H+ AH2+||Log β2 =pka2 + pka3
 * A3− + 3H+ AH3||Log β3 = pka1 + pka2 + pka3
 * }
 * A3− + 3H+ AH3||Log β3 = pka1 + pka2 + pka3
 * }
 * }

title: Buffer solution