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Invisible Ink
Invisible ink, also known as security ink or sympathetic ink, is a substance used for writing, which is invisible either on application or soon thereafter, and can later be made visible by some means, such as heat or ultraviolet light. Invisible ink is one form of steganography. History One of the earliest writers to mention an invisible ink is Aeneas Tacticus, in the 4th century BC. He mentions it in discussing how to survive under siege but does not indicate the type of ink to be used. This was part of his list of the 20 different methods of secret communications in a book called ''On the Defense of Fortifications''. One of the techniques that involved steganography involved puncturing a tiny hole above or below letters in a document to spell out a secret message. This did not include an invisible ink but the Germans improved on the method during World War I and World War II. They used invisible ink and microdots instead of pinpricks. Philo of Byzantium may be the first write ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magia Naturalis
' (in English, ''Natural Magic'') is a work of popular science by Giambattista della Porta first published in Naples in 1558. Its popularity ensured it was republished in five Latin editions within ten years, with translations into Italian (1560), French, (1565) Dutch language, Dutch (1566) and English (1658) printed. ''Natural Magic'' was revised and considerably expanded throughout the author's lifetime; its twenty books (Naples 1589) include observations upon geology, optics, medicines, poisons, cooking, metallurgy, magnetism, cosmetics, perfumes, gunpowder, and invisible writing. ''Natural Magic'' is an example of pre-Francis Bacon, Baconian science. Its sources include the ancient learning of Pliny the Elder and Theophrastus as well as numerous scientific observations made by Della Porta. Author Giambattista della Porta (also known as John Baptist Porta) was born in Vico Equense, Italy, between October 3rd and November 15th, 1535 and was the second of three sons. The Po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calligraphy Pen
A dip pen is a writing instrument used to apply ink to paper. It usually consists of a metal nib with a central slit that acts as a capillary channel like those of fountain pen nibs, mounted in a handle or holder, often made of wood. Other materials can be used for the holder, including bone, metal and plastic; some pens are made entirely of glass. Generally dip pens have no ink reservoir, so the user must refill the ink from an ink bowl or bottle to continue drawing or writing. Sometimes a simple tubular reservoir can be clipped to the top of the pen, allowing for several minutes of uninterrupted use. Refilling can be done by dipping into an inkwell, but it is also possible to charge the pen with an eyedropper, a syringe, or a brush, which gives more control over the amount of ink applied. Thus, "dip pens" are not necessarily dipped; many illustrators call them nib pens. Dip pens with replaceable metal nibs emerged in the early 19th century, when they replaced quill pens and, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toothpick
A toothpick is a small thin stick of wood, plastic, bamboo, metal, bone or other substance with at least one and sometimes two pointed ends to insert between teeth to remove detritus, usually after a meal. Toothpicks are also used for festive occasions to hold or spear small appetizers (like cheese cubes or olives) or as a cocktail stick, and can be decorated with plastic frills or small paper umbrellas or flags. History Known in all cultures, the toothpick is the oldest instrument for dental cleaning. Hominin remains from Dmanisi, Georgia, dated to about 1.8 million years ago, bear lesions indicating the repeated use of a “toothpick”. A Neanderthal man's jawbone found in the Cova Foradà in Spain evidenced use of a toothpick to alleviate pain in his teeth caused by periodontal disease and dental wear. Toothpicks made of bronze have been found as burial objects in prehistoric graves in Northern Italy and in the East Alps. In 1986, researchers in Florida discovered the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fountain Pen
A fountain pen is a writing instrument that uses a metal nib (pen), nib to apply Fountain pen ink, water-based ink, or special pigment ink—suitable for fountain pens—to paper. It is distinguished from earlier dip pens by using an internal reservoir to hold ink, eliminating the need to repeatedly dip the pen in an inkwell during use. The pen draws ink from the reservoir through a feed to the nib and deposits the ink on paper via a combination of gravity and capillary action. Filling the reservoir with ink may be achieved manually, via the use of an eyedropper or syringe, or via an internal filling mechanism that creates suction (for example, through a piston mechanism) or a vacuum to transfer ink directly through the nib into the reservoir. Some pens employ removable reservoirs in the form of pre-filled ink cartridges. History Early prototypes of reservoir pens According to Qadi al-Nu'man al-Tamimi () in his ''Kitab al-Majalis wa 'l-musayarat'', the Fatimid caliph Al-Mu'izz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rubber Stamp
A rubber stamp is an image or pattern that has been carved, molded, laser engraved, or vulcanized onto a sheet of rubber. Rubber stamping, also called stamping, is a craft in which some type of ink made of dye or pigment is applied to a rubber stamp, and used to make decorative images on some media, such as paper or fabric. Description A rubber stamp uses a raised-relief image molded into a sheet of rubber, often mounted onto a more stable object such as a wood, brick, or an acrylic block. For compactness, the vulcanized rubber image with an adhesive foam backing may be attached to a cling vinyl sheet which allows it to be used with an acrylic handle for support. These cling rubber stamps can be stored in a smaller amount of space, and typically cost less than the wood-mounted versions. They can also be positioned with a greater amount of accuracy due to the stamper's ability to see through the handle being used. The ink-coated rubber stamp is pressed onto any type of medi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stylus
A stylus is a writing utensil or tool for scribing or marking into softer materials. Different styluses were used to write in cuneiform by pressing into wet clay, and to scribe or carve into a wax tablet. Very hard styluses are also used to Engraving, engrave metal, and the slate and stylus system is used to punch out dots to write in Braille. Styluses are held in the hand and thus are usually a narrow elongated shape, similar to a modern ballpoint pen. Many styluses are heavily curved to be held more easily. The word ''stylus'' is also used to describe Stylus (computing), computer styluses used to assist in navigating or providing more precision when using touchscreens. Etymology ''Stylus'' comes from the Latin —the spelling ''stylus'' arose from an erroneous connection with Greek (), 'pillar'.''Oxford Latin Dictionary'', s.v. "stilus" (2012). The Latin word had several meanings, including "a long, sharply pointed piece of metal; the stem of a plant; a pointed instrume ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Bicarbonate
Sodium bicarbonate ( IUPAC name: sodium hydrogencarbonate), commonly known as baking soda or bicarbonate of soda (or simply “bicarb” especially in the UK) is a chemical compound with the formula NaHCO3. It is a salt composed of a sodium cation ( Na+) and a bicarbonate anion (). Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda ( sodium carbonate). The natural mineral form is nahcolite, although it is more commonly found as a component of the mineral trona. As it has long been known and widely used, the salt has many different names such as baking soda, bread soda, cooking soda, brewing soda and bicarbonate of soda and can often be found near baking powder in stores. The term ''baking soda'' is more common in the United States, while ''bicarbonate of soda'' is more common in Australia, the United Kingdom, and New Zealand. Abbreviated colloquial forms such as '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonia
Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the chemical formula, formula . A Binary compounds of hydrogen, stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pungent smell. It is widely used in fertilizers, refrigerants, explosives, cleaning agents, and is a precursor for numeous chemicals. Biologically, it is a common nitrogenous waste, and it contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to fertilisers. Around 70% of ammonia produced industrially is used to make fertilisers in various forms and composition, such as urea and diammonium phosphate. Ammonia in pure form is also applied directly into the soil. Ammonia, either directly or indirectly, is also a building block for the synthesis of many chemicals. In many countries, it is classified as an List of extremely hazardous substances, extremely hazardous substance. Ammonia is toxic, cau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constipation
Constipation is a bowel dysfunction that makes bowel movements infrequent or hard to pass. The Human feces, stool is often hard and dry. Other symptoms may include abdominal pain, bloating, and feeling as if one has not completely passed the bowel movement. Complications from constipation may include hemorrhoids, anal fissure or fecal impaction. The normal frequency of bowel movements in adults is between three per day and three per week. Babies often have three to four bowel movements per day while young children typically have two to three per day. Constipation has many causes. Common causes include slow movement of stool within the colon, irritable bowel syndrome, and pelvic floor disorders. Underlying associated diseases include hypothyroidism, diabetes, Parkinson's disease, celiac disease, non-celiac gluten sensitivity, Vitamin B12 deficiency, vitamin B12 deficiency, colon cancer, diverticulitis, and inflammatory bowel disease. Medications associated with constipation in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenolphthalein
Phenolphthalein ( ) is a chemical compound with the chemical formula, formula carbon, C20hydrogen, H14oxygen, O4 and is often written as "HIn", "HPh", "phph" or simply "Ph" in shorthand notation. Phenolphthalein is often used as an indicator in acid–base titrations. For this application, it turns colorless in acidic solutions and pink in base (chemistry), basic solutions. It belongs to the class of dyes known as phthalein dyes. Phenolphthalein is slightly soluble in water and usually is dissolved in Alcohol (chemistry), alcohols in experiments. It is a weak acid, which can lose Hydrogen ion, H+ ions in solution. The nonionized phenolphthalein molecule is colorless and the double deprotonated phenolphthalein ion is Fuchsia (color), fuchsia. Further proton loss in higher pH occurs slowly and leads to a colorless form. Phenolphthalein ion in concentrated sulfuric acid is orange red due to sulfonation. Uses pH indicator Phenolphthalein's common use is as an indicator in acid-ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Revolution
The American Revolution (1765–1783) was a colonial rebellion and war of independence in which the Thirteen Colonies broke from British America, British rule to form the United States of America. The revolution culminated in the American Revolutionary War, which was launched on April 19, 1775, in the Battles of Lexington and Concord. Leaders of the American Revolution were Founding Fathers of the United States, colonial separatist leaders who, as British subjects, initially Olive Branch Petition, sought incremental levels of autonomy but came to embrace the cause of full independence and the necessity of prevailing in the Revolutionary War to obtain it. The Second Continental Congress, which represented the colonies and convened in present-day Independence Hall in Philadelphia, formed the Continental Army and appointed George Washington as its commander-in-chief in June 1775, and unanimously adopted the United States Declaration of Independence, Declaration of Independence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
