A jack-o'-lantern is a carved pumpkin, turnip, or other root vegetable lantern associated with Halloween. Its name comes from the phenomenon of a strange light flickering over peat bogs, called will-o'-the-wisp or jack-o'-lantern; the name is tied to the Irish legend of Stingy Jack, a drunkard who bargains with Satan and is doomed to roam the Earth with only a hollowed turnip to light his way. Jack-o'-lanterns are a yearly Halloween tradition that came to the United States from Irish immigrants. In a jack-o'-lantern, the top of the pumpkin or turnip is cut off to form a lid, the inside flesh is scooped out, an image—usually a scary or funny face—is carved out of the rind to expose the hollow interior. To create the lantern effect, a light source, traditionally a flame such as a candle or tea light, is placed within before the lid is closed. However, artificial jack-'o-lanterns with electric lights are marketed, it is common to see jack-o'-lanterns on doorsteps and otherwise used as decorations prior to and on Halloween.

The term jack-o'-lantern was used to describe the visual phenomenon ignis fatuus known as a will-o'-the-wisp in English folklore. Used in East England, its earliest known use dates to the 1660s; the term "will-o'-the-wisp" uses "wisp" and the proper name "Will": thus, "Will-of-the-torch." The term jack o'lantern is of the same construction: "Jack of lantern." The carving of vegetables has been a common practice in many parts of the world, gourds were one of the earliest plant species farmed by humans c. 10,000 years ago. For example, gourds were used to carve lanterns by the Māori over 700 years ago, it is believed. In the 19th century, "turnips or mangel wurzels, hollowed out to act as lanterns and carved with grotesque faces," were used on Halloween in parts of Ireland and the Scottish Highlands. In these Gaelic-speaking regions, Halloween was the festival of Samhain and was seen as a time when supernatural beings, the souls of the dead, walked the earth. Jack-o'-lanterns were made at Halloween time in Somerset during the 19th century.

By those who made them, the lanterns were said to represent either spirits or supernatural beings, or were used to ward off evil spirits. For example, sometimes they were used by Halloween participants to frighten people, sometimes they were set on windowsills to keep harmful spirits out of one's home, it has been suggested that the jack-o'-lanterns represented Christian souls in purgatory, as Halloween is the eve of All Saints' Day /All Souls' Day. On Halloween in 1835, the Dublin Penny Journal published a long story on the legend of "Jack-o'-the-Lantern". In 1837, the Limerick Chronicle refers to a local pub holding a carved gourd competition and presenting a prize to "the best crown of Jack McLantern"; the term "McLantern" appears in an 1841 publication of the same paper. There is evidence that turnips were used to carve what was called a "Hoberdy's Lantern" in Worcestershire, England, at the end of the 18th century; the folklorist Jabez Allies recalls: Adaptations of Washington Irving's short story "The Legend of Sleepy Hollow" show the Headless Horseman with a pumpkin or jack-o'-lantern in place of his severed head.

The application of the term to carved pumpkins in American English is first seen in 1834. The carved pumpkin lantern's association with Halloween is recorded in the 1 November 1866 edition of the Daily News: The old time custom of keeping up Hallowe'en was not forgotten last night by the youngsters of the city, they had their maskings and their merry-makings, perambulated the streets after dark in a way, no doubt amusing to themselves. There was a great sacrifice of pumpkins from which to make transparent heads and face, lighted up by the unfailing two inches of tallow candle. James Fenimore Cooper wrote a nautical novel titled the Privateer; the Jack O'lantern was the name of the ship. The poet John Greenleaf Whittier, born in Massachusetts in 1807, wrote the poem "The Pumpkin": Agnes Carr Sage, in the article, "Halloween Sports and Customs" (Harper's Young People: It is an ancient British custom to light great bonfires on Hallowe'en, carry blazing fagots about on long poles. In the United States, the carved pumpkin was first associated with the harvest season in general, long before it became a symbol of Halloween.

In 1895, an article on Thanksgiving entertaining recommended a lit jack-o'-lantern as part of the festivities. The story of the jack-o'-lantern comes in many forms and is similar to the story of Will-o'-the-wisp retold in different forms across Western Europe, Italy, Norway and Sweden. In Switzerland, children will leave bowls of milk or cream out for mythical house spirits called Jack o' the bowl. An old Irish folk tale from the mid-18th century tells of Stingy Jack, a lazy yet shrewd blacksmith who uses a cross to trap Satan. One story says that Jack tricked Satan into climbing an apple tree, once he was up there, Jack placed crosses around the trunk or carved a cross into the bark, so that Satan couldn't get down. Another version of the story s

Ferricyanide is the anion 3−. It is called hexacyanoferrate and in rare, but systematic nomenclature, hexacyanidoferrate; the most common salt of this anion is potassium ferricyanide, a red crystalline material, used as an oxidant in organic chemistry. 3− consists of a Fe3+ center bound in octahedral geometry to six cyanide ligands. The complex has Oh symmetry; the iron is low spin and reduced to the related ferrocyanide ion 4−, a ferrous derivative. This redox couple is reversible and entails no making or breaking of Fe–C bonds: 3− + e− ⇌ 4−This redox couple is a standard in electrochemistry. Compared to normal cyanides like potassium cyanide, ferricyanides are much less toxic because of the tight hold of the CN− to the Fe3+, they do react with mineral acids, however, to release toxic hydrogen cyanide gas. Treatment of ferricyanide with iron salts affords the brilliant, long-lasting pigment Prussian blue, the traditional color of blueprints. Potassium ferricyanide Ferrocyanide

The White Hall Foundry is a historic iron foundry located at 102 S. Jacksonville St. in White Hall, Illinois. The foundry was built in 1877 for brothers George W. and Richard B. Winn, it produced cast iron for new buildings in White Hall, making it an important part of the city's economy during a building boom in the late 19th century. The building is a small brick structure with well-crafted details for an industrial building, such as its cornice and fanlights; the internal truss system supporting the building's roof is an example of an inverted Kingpost truss. The foundry was added to the National Register of Historic Places on May 28, 1980, it is part of the White Hall Historic District, listed on the National Register