# General Information (A)

1-chloro-3-ethyl-1-penten-4 yn-3-ol
1-chloro-3-ethyl-1-penten-4 yn-3-ol (Placidyl, ethchlorvynol) is a depressive drug administered orally or injected as a short term treatment for insomnia. It is a sedative hypnotic and a Central Nervous System (CNS) depressant and muscle relaxant.

A & B Leads
A & B Leads is a designation of leads derived from the midpoints of the two pairs comprising a 4-wire circuit.

Ab
Ab is the eleventh month of the Jewish civil year.

Aba
An aba is a sack like garment worn by Arabs.

Abac
An abac is a two dimensional matrix, or table, found at the back of a road atlas which shows the distances between major towns etc.

Abaculi
Abaculi are small cubes of coloured glass, enamel, stone or other material used in marquetry and mosaic work.

Abacus
An abacus is a counting frame with balls sliding on wires. It was first used before the adoption of the ten digit numeric system and is still widely used in China.

Abaft
Abaft means towards the rear of a ship.

Abatement
In English law, abatement refers to legal proceedings which are formerly abated, or ended, on the marriage, death or bankruptcy of one of the parties, or some change of interest in the matter in dispute.

Abba
Abba is a devotional expression for the Divine Fatherhood, and apparently the chief appellation of God used by Jesus in prayer. The name was also adopted by a Swedish seventies pop band from their initials.

Abbey
An abbey is a body of monks or a monastic building.

Abbotsford Club
The Abbotsford Club was founded in 1834 on the model of the Bannatyne and Maitland Clubs and printed works of history and antiquities having relation to Scott and the Waverley Novels. Between 1835 and 1864 the club issued 34 volumes before it closed.

Abbreviate
Abbreviate means make shorter.

Abbreviated Dialling
Abbreviated Dialling is pre-programming of a caller's phone system or long distance company's switch to recognise a 2- to 4-digit number as an abbreviation for a frequently dialled phone number, and automatically dial the whole number.

Abbreviation
An abbreviation is a short form of a word or words.

ABC Process
The ABC Process was a method of purifying sewage which derived its name from the articles used: sulphate of alumina, blood, charcoal and clay.

Abdicate
Abdicate means to renounce one's thrown.

Abdomen
The abdomen is the part of a creature's body between diaphragm and pelvis.

Abduct
Abduct means to take away by force or fraud.

Aberdeen Act
The Aberdeen Act was introduced by the earl of Aberdeen, and passed in 1845, to enforce the observance of a convention made with Brazil in 1826 to put down the slave trade. It was repealed in 1869.

Aberdeen Line
The Aberdeen Line was a British steamship company founded in 1824 and plying between London and Australia via the Cape.

Aberration
Aberration is another word for error.

Abib
Abib is the Jewish first month of the ecclesiastical year, when the feast of the Passover is celebrated. It was later named Nisan.

Abietic acid
Abietic acid is a texturiser in soaps. It is obtained from pine resin.

Abington Law
Abington Law is an English equivalent of Jeddart Justice - that is of hanging a man in haste, and trying him at leisure - it comes from the summary hanging of a man at Abington by Major-General Brown.

Abiogenesis
Abiogenesis is a term applied by Thomas Huxley in 1870 to the theory that living matter may be produced from non-living.

Ablution
Ablution is ceremonial washing.

Abnormal
Abnormal means deviating from normal.

Abode
Abode is a place where something lives.

Abomasum
An abomasum is the fourth stomach of a ruminant.

Abort
Abort means to terminate early.

Abortion
Abortion is the expulsion of the foetus from the uterus.

Aboulia
In psychology aboulia is the loss of will.

Abracadabra
Abracadabra is a qabbalistic magic word used by the Gnostics and others of the second century and later as a spell to secure the assistance of good spirits against evil. It was supposed, when written in the form of a triangle and worn around the neck for nine days, to act as a charm against fevers etc. The word first occurs in a poem by Sammonicus.

Abrasion
An abrasion is a sore place on the skin caused by rubbing.

Abridge
Abridge means to shorten by condensing.

Abscess
An abscess is a pus filled infection of an animal.

Abseil
In mountaineering abseil means to descend using a rope.

Absentee Tax
Absentee Tax was a tax of 4 shillings in the pound levied in Ireland in 1715 on the incomes and pensions of absentees. It was long complained of and was abolished in 1753. A tax of 2 shillings in the pound was proposed in 1773 by Flood and in 1783 by Molyneux, but neither attempt to reinstate the tax were successful.

Absinth
Absinth is a strong alcoholic drink containing from 60 to 80 percent alcohol. It contains wormwood oil which gives it its distinctive taste, but also toxic qualities.

Absolute
Absolute is that which is freed from relation, limitation or dependence. As an adjective it is therefore applied to the essence of a thing apart from its relations or appearances, and also to the complete or perfect state of being. Hence comes its substantial meaning of 'The Absolute' as the self-existent, self-sufficient Being, that which is free from all limitation, the all-inclusive Reality. The absolute in one form or another forms a central feature in the philosophical systems of Spinoza, Schelling and Hegel.

Absolute Delay
Absolute Delay is the actual time taken for a signal to transit a telecommunications circuit from end to end; affected by the actual circuit length and the "propagation constants" of the type of medium in use.

Absolute Temperature
Absolute Temperature is temperature based on the absolute zero of temperature (-273 degrees Celsius or 0 degrees Kelvin) at which a body possesses no thermal energy.

Absolute Zero
In chemistry, absolute zero is the temperature, 273 degrees below the zero of the centigrade scale, at which all molecular motion ceases.

Absorber Circuit
In electronics, an absorber circuit is a combination of a resistor and a capacitor in series, connected across the terminals of a switch or other circuit-breaking device in an oscillatory circuit. Its function is to damp the circuit and thus to prevent sparking or arcing when the current is interrupted.

Absorptiometer
An absorptiometer is an instrument for the accurate measurement of the absorption and transmission of light by semi-transparent substances and used for the determination of turbidity, fluorimetry, etc.

Abstract
Abstract means theoretical rather than practical.

Acardia
Acardia is the condition of a person born without a heart.

Accelerating Electrode
An accelerating electrode is an electrode in an electron tube which is maintained at a positive potential with respect to the cathode and any other electrodes situated between the cathode and the accelerating electrode, thus imparting acceleration to electrons in the direction away from the cathode. Although this definition includes the anode of the tube, the term is usually reserved for accelerating electrodes other than the anode.

Accelerating Grid
In electronics, an accelerating grid is an accelerating electrode in the form of a grid.

Acceleration
Acceleration is the rate at which a moving body increases in velocity.

Accelerator
An accelerator is a device for increasing speed.

Accelerator Valve
An accelerator valve is a thermionic valve employed as a particle accelerator.

Accelerometer
An accelerometer is an apparatus, either mechanical or electromechanical, for measuring acceleration or deceleration - that is, the rate of increase or decrease in the velocity of a moving object. Accelerometers are used to measure the efficiency of the braking systems on road and rail vehicles; those used in aircraft and spacecraft can determine accelerations in several directions simultaneously. There are also accelerometers for detecting vibrations in machinery.

Accent
An accent is a local mode of pronunciation in speech.

Acceptance Test
An acceptance test is a test operation of a new or modified device or system before usage by customers; ascertaining performance is to specifications. The FCC equivalent is "Proof of Performance Testing."

Access Charge
Access Charge is a cost assessed to users for connection ability to the interexchange, interstate message toll telephone networks of IEC's by the user's LEC, to send and receive calls beyond the immediate local exchange area. May be per minute fees levied on long distance companies, Subscriber Line Charges (SLCs) levied directly on regular local lines, fixed monthly fees for special telco circuits (i.e. WAL, DAL, T-1), or Special Access Surcharge (SAS) on special access circuits.

Access Code
In PBXs, an access code is a digit or digits dialled prior to dialling an outside call (most typically "9", or a digit entered on a feature phone set to activate functions like Call Forwarding or Conference Add-on (most typically "*" or "#")

Access Line
An access line is a telephone circuit connecting a customer location to a public network switching centre.

Accolade
Accolade is the ceremony by which knighthood is conferred. Originally it was an embrace around the neck, today is a gentle blow on the shoulders with the flat of a sword. An accolade is given by a Sovereign or his representative.

Accomplice
An accomplice is someone associated with somebody else in the committing of a crime.

Accordion
An accordion is a small portable musical instrument with a keyboard and bellows. It was invented by Damian in 1829.

Account Code
In PBXs, an account code is a code digit or digits a user must enter before or after a call is dialled, to establish accounting for the charges for the call.

Accounts
Accounts are a statement of income and expenditure.

Accumulator
In electrical terms, an accumulator stores electrical energy.

Ace
An ace is a playing card with one pip.

Acesulfame-K
Acesulfame-K is an artificial sweetener, manufactured by Hoechst, a giant German chemical company, and widely used around the world. It is about 200 times sweeter than sugar and is marketed under the name Sunett. In the United States, for several years acesulfame-K was permitted only in such foods as sugar-free baked goods, chewing gum, and gelatin desserts. In July 1998, the FDA allowed this chemical to be used in soft drinks, thereby greatly increasing consumer exposure. Studies on rats indicate that it may cause cancer.

Acetal
Acetal is a colourless liquid formed by oxidation of alcohol.

Acetaldehyde
Acetaldehyde is a colourless liquid with a pungent, fruity odour. It is used primarily as a chemical intermediate, principally for the production of acetic acid, pyridine and pyridine bases, peracetic acid, pentaerythritol, butylene glycol, and chloral. It is used in the production of esters, particularly ethyl acetate and isobutyl acetate. It is also used in the synthesis of crotonaldehyde, flavour and fragrance acetals, acetaldehyde 1,1-dimethylhydrazone, acetaldehyde cyanohydrin, acetaldehyde oxime, and various acetic esters, paraldehyde, metaldehyde, polymers, and various halogenated derivatives. Acetaldehyde is used in denatured alcohol. In the past it was a chemical intermediate for 2-ethyl-1-butanol, glyoxal, acrolein, and acetaldehyde-aniline condensate. Acetaldehyde has been used in the manufacture of aniline dyes and synthetic rubber, to silver mirrors, and to harden gelatin fibres. It has been used in the production of polyvinyl acetal resins, in fuel compositions, and to inhibit mould growth on leather. It is also used in the manufacture of disinfectants, drugs, perfumes, explosives, lacquers, varnishes, photographic chemicals, phenolic and urea resins, rubber accelerators, antioxidants, and room air deodorisers. It is also a pesticide intermediate. Acetaldehyde is a compound for the intended use as a flavouring agent and adjuvant. It is an important component of food flavourings added to milk products, baked goods, fruit juices, candy, desserts, and soft drinks; the concentration of acetaldehyde in food is usually up to .047%. It is an especially useful synthetic flavouring ingredient to impart orange, apple, and butter flavours, and is used in the manufacture of vinegar and yeast and as a fruit and fish preservative. Acetaldehyde is a volatile and flammable liquid. It is miscible in water, alcohol, ether, benzene, gasoline, solvent, naphtha, toluene, xylene, turpentine, acetone, and other common organic solvents. It is a highly reactive compound that
undergoes numerous condensation, addition, and polymerisation reactions. It is dangerous when exposed to heat or flame; it can react vigorously with oxidising material, acid anhydrides, alcohols, ketones, phenols, halogens, isocyanates, and strong alkalies and amines. It is also incompatible with acids, bases, alcohol, ammonia, amines, phenols, ketones, and hydrogen cyanide. It will polymerise readily in the presence of trace metals. Acetaldehyde can form unstable or explosive peroxides with exposure to the air. It may polymerise under influence of air and heat, acids, or bases with potential of fire or explosion. It is polymerised violently by concentrated sulphuric acid. Rubber products decompose on contact with acetaldehyde, but it is not corrosive to most metals. It is also known as acetic aldehyde, ethanal, NCI-C56326, and ethyl aldehyde.

Acetaminophen
Acetaminophen is a drug used to treat mild pain or fever. It has the possible side effects of: Rash, itching and severe liver damage with over dosing.

Acetanilide
Acetanilide (phenyl-acetamide) was a medicine used as an antipyretic and analgesic in place of quinnine.

Acetic acid
Acetic acid is an organic acid with the formulae ch3cooh.

Acetic Aldehyde
see "Acetaldehyde"

Acetic ether
see "Ethyl Acetate"

Acetone
Acetone is the simplest and most important of the ketones. It is a colourless liquid with a mildly pungent and somewhat aromatic odour. It is primarily used as a chemical intermediate and as a solvent for cellulose acetate and nitro-cellulose. It is used as a carrier for acetylene, and as a raw material for the chemical synthesis of a wide range of products such as ketene, methyl methacrylate, bisphenol A, diacetone alcohol, mesityl oxide, methyl isobutyl ketone, hexylene glycol, and isophorone. Acetone is a mobile, flammable liquid that is miscible in all proportions with water and with organic solvents such as ether, methanol, ethyl alcohol, and esters. It is incompatible and reactive with oxidisers and acids. Containers of acetone may explode in a fire, producing poisonous gases. Acetone fires may be controlled with carbon dioxide or dry chemical extinguishers. Acetone undergoes many condensation reactions; in the presence of an amine, or ammonia, various esters condense readily with acetone. Acetone is also known commercially as dimethyl ketone, methyl ketone, dimethylformaldehyde, ketone propane, and 2-propanone.

Acetophenone
Acetophenone (phenyl-methyl-ketone) is a medicine formerly used to induce sleep.

Acetylcholine
Acetylcholine (Ach) is a chemical that serves as a neurotransmitter, communicating nerve impulses between the cells of the nervous system. It is largely associated with the transmission of impulses across the synapse between nerve and muscle cells, causing the muscles to contract. ACh is produced in the synaptic knob and stored in vesicles until a nerve impulse triggers its discharge across the synapse. When the ACh reaches the membrane of the receiving cell it binds with a specific site and brings about depolarisation – a reversal of the electric charge on either side of the membrane causing a fresh impulse in nerve cells or a contraction in muscle cells. Its action is short-lived because it is quickly destroyed by the enzyme cholinesterase. Anticholinergic drugs have a number of uses in medicine to epblock the action of ACh, thereby disrupting the passage of nerve impulses and relaxing certain muscles, for example in premedication before surgery.

Acetylene
Acetylene is a highly inflammable gas of the hydrocarbon family used for welding and cutting metals. It was discovered by Berthelot. In 1862 Wohler discovered that carbide of calcium treated with water produced lime and acetylene. In 1895 acetylene was cheaply produced on a commercial scale and subsequently was used for general lighting.

Ach
see "Acetylcholine"

Achor
Achor is (was?) a disease of infants, in which the head, face and breast become encrusted with thin, yellowish or greenish scabs.

Achromatic Telescope
An achromatic telescope is a telescope in which colour is got rid of. They were invented by Jogn Dollond around 1753.

Acid
An acid is a chemical compound that reacts with metals to form salts by releasing hydrogen. All acids contain hydrogen, some also contain oxygen and these are called oxy-acids. Varying amounts of oxygen in an acid are reflected in its name ending -ous or -ic, and the salts formed from such acids are similarly named ending in -ite and -ate.

Acid Buf
Acid Buf is a tradename for calcified seaweed - lithothamnium calcareum.

Acid of Sugar
see "Oxalic Acid"

ACK
In telecommunications, ACK is the 'acknowledge' character in many data codes; used most commonly for an affirmative response of correct receipt.

Aclinic
The aclinic is a magnetic equator.

Acne
Acne is a skin eruption due to inflammation of the sebaceous glands.

Aconitine
Aconitine is a poisonous alkaloid derived from aconite.

Acorn Valve
An acorn valve is a form of thermionic valve used at ultra-high frequencies, in which, by adopting very small dimensions and special constructions, the inter-electrode capacitances, lead inductances and transit time effects are greatly reduced.

Acoustic
The term acoustic refers to hearing.

Acoustic Coupler
An acoustic coupler is means of connecting external devices to a telephone handset avoiding direct electrical connection; most commonly used for low-speed data terminals.

Acoustic Feedback
Acoustic feedback is the return of acoustic energy from the output of a sound reproducing equipment, such as a microphone-amplifier-loudspeaker combination, to the input or to an intermediate stage, thereby causing the system to generate sustained oscillations which are manifested as continual howling.

Acoustics
see "acoustic"

Acre
An acre is an ancient measurement of land area being (since 1824) 4840 square yards. Prior to that Edward I introduced the first standard for the acre in Britain.

Acridine
Acridine is an organic compound with the formulae c13h9n used in dyes and drugs.

Acriflavine
Acriflavine is an antiseptic powder.

Acro-lase
see "Phenobarbital"

Acromegaly
Acromegaly is a disease due to over activity of the pituitary gland results in excessive bone growth, especially the skull.

Acronym
An acronym is a word formed from the initials of other words.

Acrophobia
Acrophobia is the fear of high places.

Acropolis
The acropolis was the citadel of ancient Greek cities.

Acrostic
An acrostic is a poem in which the first or last letters of each line, read downwards, form a word or sentence. Double acrostics became very popular in 1867.

Acrylamide
Acrylamide is an odourless, free-flowing white crystalline used as a chemical intermediate in the production and synthesis of polyacrylamides. These high-molecular weight polymers can be modified to develop non-ionic, anionic, or cationic properties for specific uses. The principle end use of acrylamide is in water-soluble polymers used as additives for water treatment, enhanced oil recovery, flocculants, papermaking aids, thickeners, soil conditioning agents, sewage and waste treatment, ore processing, and permanent press fabrics. Acrylamide is also used in the synthesis of dyes, in copolymers for contact lenses, and the construction of dam foundations, tunnels, and sewers. The largest use for polyacrylamide is in treating municipal drinking water and wastewater. The polymer is also used to remove suspended solids from industrial wastewater before discharge, reuse, or disposal. Acrylamides also find use in oil-drilling processes to control fluid losses. In the pulp and paper industry, polyacrylamides are used as binders and retention aids for fibres and to retain pigments on paper fibres. Acrylamide is a soil stabiliser and also finds use in foundry operations to facilitate free sand flow into moulds. Home appliances, building materials, and automotive parts are coated with acrylamide resins and thermosetting acrylics. Acrylamides are formulated in cosmetics and soap preparations as thickeners and in dental fixtures, hair grooming preparations, and preshave lotions. Minor uses of acrylamide are as latex thickeners, emulsion stabilisers for printing inks, gelling agents for explosives, binders in adhesives and adhesive tape, in the production of diazo compounds, and for gel chromatography and electrophoresis. Acrylamide occurs in crystalline form and in aqueous solution. It is soluble in water, methanol, ethanol, dimethyl ether, and acetone; it is insoluble in benzene and heptane. The monomer readily polymerises at the melting point or under ultraviolet light.
d acrylamide is stable at room temperature, but may polymerise violently when melted or in contact with oxidising agents such as chlorine dioxide and bromine. When heated to decomposition, acrylamide emits a poisonous gas, acrid fumes, and NOx. If heating to high temperatures, acrylamide can explode. Acrylamide is also known as acrylamide monomer, acrylic amide, propenamide, and 2-propenamide.

Acrylamide monomer
see "Acrylamide"

Acrylic
Acrylic is a synthetic fibre derived from acrylic acid.

Acrylic amide
see "Acrylamide"

Act of Succession
The Act of Succession in 1534 declared the marriage of Henry VIII and Catherine of Aragon null and void, and settled the succession to the throne on the heirs of Henry VIII by Anne Boleyn.

Actinide
An actinide is an element with an atomic number between 89 and 103.

Actinium
Actinium is a radioactive trivalent element that resembles lanthanum in chemical properties and is found especially in pitchblende. It has the symbol Ac.

Actinometer
An actinometer is an instrument for measuring heat radiation.

ActiveX
ActiveX is a technology developed by Microsoft for sharing information among different applications. ActiveX is an outgrowth of two other Microsoft technologies: OLE (Object Linking and Embedding) and COM (Component Object Model). ActiveX supports features that enable it to take advantage of the Internet. For example, an ActiveX control can be automatically downloaded and executed by a Web browser. ActiveX is not a programming language, but rather a set of rules for how applications should share information. Programmers can develop ActiveX controls in a variety of languages, including C , C++, Visual Basic, and Java. An ActiveX control is similar to a Java applet. Unlike Java applets, however, ActiveX controls have full access to the Windows operating system. This gives them more power than Java applets, but also the risk that the control may damage software on your machine. To control this risk, Microsoft developed a registration system so that browsers can identify and authenticate an ActiveX control before downloading it. Another difference between Java applets and ActiveX controls is that Java applets run on all platforms, whereas ActiveX controls are currently limited to Windows environments. Related to ActiveX is the scripting language VBScript that enables Web authors to embed interactive elements in HTML documents. Just as JavaScript is similar to Java, so VBScript is similar to Visual Basic. Currently, Microsoft's Web browser, Internet Explorer, supports Java, JavaScript, and ActiveX, whereas Netscape's Navigator browsers support only Java and JavaScript.

Acts of Supremacy
The Acts of Supremacy were passed in 1534 enacting that the King (Henry VIII) was the only supreme head on earth of the Church of England, with power to redress all heresies and abuses.

Ada
Ada is a computer programming language developed for the US Department of Defence which permits the development of very large computer systems and can cope with complex real-time applications. It was named after Augusta Ada King, Countess of Lovelace, daughter of Lord Byron, who worked with Charles Babbage.

Adagio
Adagio is a musical term indicating that the movement should be played slowly and expressively.

Adaptive Equalisation
Adaptive Equalisation is equalisation of received digital signals capable of adjustment during actual transmission.

Adaptive Equalisation
Adaptive Equalisation is a telecommunications term referring to the equalisation of received digital signals capable of adjustment during actual transmission.

Adaptive Routing
In data networks, adaptive routing is routing algorithms capable of adjusting message routes in response to changes in traffic patterns or transmission channel failures.

Adcock Aerial
an Adcock aerial is a radio aerial system consisting of two vertical open-spaced dipoles with screened horizontal connections. It thus responds almost exclusively to the vertically polarised component of a received wave and is used for radio direction finding.

Addiction
Addiction is a state of dependence caused by the habitual use of drugs, alcohol, or other substances. It is characterised by uncontrolled craving, tolerance, and symptoms of withdrawal when access is denied. Habitual use produces changes in body chemistry and treatment must be geared to a gradual reduction in dosage. Initially, only opium and its derivatives (morphine, heroin, codeine) were recognised as addictive, but many other drugs, whether therapeutic (such as tranquillisers) or recreational (such as cocaine and alcohol), are now known to be addictive. Research points to a genetic predisposition to addiction; environment and psychological make-up are other factors. Although physical addiction always has a psychological element, not all psychological dependence is accompanied by physical dependence. A carefully controlled withdrawal programme can reverse the chemical changes of habituation. A cure is difficult because of the many other factors contributing to addiction.

Addiscombe College
Addiscombe College was a college near Croydon, Surrey, which was purchased by the East India Company in 1809, for the education of candidates for scientific branches of the Indian army. It was closed in 1861.

Addison's Disease
Addison's Disease is a dangerous affection of the renal capsules. It was first described by Thomas Addison in 1855.

Addition reaction
In chemistry, addition reaction is a reaction in which a reagent adds to a carbon-carbon double or triple bond.

Additional Forces Act
The Additional Forces Act was passed in Britain by Pitt, owing to the imminent danger of the invasion of the country by Napoleon in 1803 and the following years. The act legalised the formation of second battalions to the regular regiments then serving abroad. The United Kingdom was divided up into districts, which were required by the act to furnish quotas of 3000 men each. The act was repealed after the death of Pitt.

Adenine
Adenine is a base derived from purine; one of the five found in nucleic acids, where it is generally paired with thymine or uracil.

Adenitis
Adenitis is an inflammation of the lymphatic glands. It may be either acute or chronic. As a rule, adenitis is a symptom of some disease process within the area of the body that is drained by the lymphatic channels in which the affected lymphatic glands are situated. In acute adenitis the disease is usually an infected wound or sore, the invading micro-organisms being carried away by the lymphatics and trapped in the glands, where, in turn, they set up inflammation, causing enlargement of the gland, and sometimes suppuration. Chronic adenitis may be due to a chronic infection, such as tuberculosis. Lymphatic glands are also the seat of secondary cancer, the malignant growth cells being carried along the lymphatic channels from the primary cancer. Lymphadenoma or Hodgkin's disease also causes enlargement of the lymphatic glands.

Adenosine triphosphate
Adenosine triphosphate is a molecule formed by the condensation of adenine, ribose and triphosphoric acid. It is a key compound in the mediation of energy in both plants and animals. Energy is stored when it is synthesised from adenosine diphosphate and phosphoric acid and released when the reaction is reversed.

Adhesive
An adhesive is a sticky substance.

Adipocere
Adipocere is a substance in dead bodies formed by decomposition of fatty acids when exposed to moisture.

Adit
An adit is the horizontal entrance to a mine.

Admiralty
The admiralty was the board of state charged with the provision, organisation and control of the royal navy. It was founded by Henry VIII and amalgamated in 1964 into the ministry of defence.

Adnams
Adnams is an English beer brewing company of Suffolk. They were established in 1890.

Adnams Regatta
Adnams Regatta is an English summer ale brewed with English pale ale malts and Goldings hops.

Adobe
An adobe is a Mexican house made of clay bricks.

Adobe Acrobat
Adobe Acrobat is a coding system developed by Adobe Systems for electronic publishing applications. It was launched 1993. Acrobat coding was designed to turn computers into information distributors that would allow Macintosh users to view a document in its original form, and can be generated directly from PostScript files.

Adobe Illustrator
Adobe Illustrator is an illustration program for the PC and Mac for creating high-quality PostScript line drawings. It includes the tools of a basic drawing program, and also provides the ability to use lines and curves to trace a bit-mapped image and run it into crisp PostScript output. This can be done manually with the pen tool or automatically using the AutoTrace tool. AutoTrace automatically traces shapes from a template, which saves time. The end result is a PostScript line-art drawing that can be printed in a resolution limited only by the output device. The product should be considered for translating bitmapped graphics to PostScript drawings. Adobe Illustrator uses Bezier curves which are composed of anchor points (ends of the curve) and direction points. Direction points determine the shape of your curve. You can reshape the curve by dragging its points. You can also add and move anchor points and delete sections of your curve.

Adobe PageMill
Adobe PageMill is a commercial Windows HTML editor. It was originally developed for the Macintosh, it is also available for Windows 95 offering WYSIWYG HTML editing as well as incorporation of many of the most popular Web capabilities.

Adsorption
In chemistry, adsorption is a process in which molecules or ions adhere to the surface of a solid.

Adult
An adult is a fully grown being.

Advent
Advent was the prototypical computer adventure game, first implemented on the PDP-10 by Will Crowther as an attempt at computer-refereed fantasy gaming, and expanded into a puzzle-oriented game by Don Woods. Now better known as Adventure, but the TOPS-10 operating system permitted only six-letter filenames.

Adytum
An adytum is the inner most part of a temple.

Adze
An adze is a carpenter's tool for cutting away the surface of wood.

Aelfric Society
The Aelfric Society was founded in 1842 to publish the Homilies of Aelfric, archbishop of Canterbury and other Anglo-Saxon works. It closed in 1856.

Aeneid
The Aeneid is Virgil's epic poem in twelve books, setting forth the wanderings of Aeneas. The poem has been translated into English several times, among others by Gawin Douglas in 1513, Dryden in 1697 and William Morris in 1876.

Aeolian Harp
The Aeolian Harp is a sounding-board on which are strung several gut strings of different thickness; these are tuned to the same note and give its various harmonics when made to vibrate by the wind. Its invention is ascribed to St Dunstan, but in its present form it is not thought to have existed before the 17th century.

Aeolipile
An aeolipile is a hollow metallic ball which rotates about its vertical axis, with horizontal arm-like tubes projecting radially, and having their free ends bent round in a tangential direction. When the water in the globe is heated, and steam rushes out of the tubes, rotation is established. The aeolipile was invented in 120 BC.

Aeolopile
The aeolopile is a hollow ball with an orifice where a tube might be screwed. It was used in the 17th century as a boiler for experimental steam-engines. A similar apparatus is described by Vitruvius in the first century, and its invention is generally attributed to Hiero of Alexandria.

Aeolotropy
Aeolotropy is the antithesis of isotropy. It is the state of those bodies or substances which do not exhibit the same qualities in all directions.

Aeon
An aeon is an immeasurable period.

Aerated Water
Aerated water (soda water) is a solution of carbonic acid in water. It was discovered by Priestly and suggested as a prevention of scurvy, a paper being presented to the Admiralty in 1773. Certainly sailors drank aerated water on board ship as a bottle was found from the Royal George which sank in 1780.

Aerial
An aerial is a receiving or radiating device used in radio communications.

Aerodrome
An aerodrome is a place where aircraft are based.

Aerophore
The aerophore was an apparatus invented by Denayrouze to enable persons to enter a noxious inflammable atmosphere. It comprised an air-pump, lamp, and flexible tubing. It was tried at Chatham in January 1875 and was reported successful.

Aerostatic Press
An aerostatic press is an apparatus by which the pigments are extracted from dyewoods. In use, a solvent is forced through the wood by atmospheric pressure.

Aerotherapeutics
Aerotherapeutics is a method of treating disease by varying the pressure of the surrounding atmosphere, or by modifying its composition, or by change of climate. Atmospheric pressure may be varied in an air-tight chamber.

Aestivation
In zoology, aestivation is a summer sleep (rather like hibernation). It is not uncommon in animals who live in hot climates, especially those who require a degree of moisture, thus both land and water tortoises frequently retire into cavities of the ground during heat and drought and remain there until the recurrence of the rainy season.

Affenthaler
Affenthaler is a red wine which takes its name from the Village of Affenthaler in Baden.

Affettuoso
Affettuoso is an Italian musical term indicating a tender and affecting style; it lies between adagio and andante, and is frequently joined with these terms.

Aflatoxin
Aflatoxin is a toxin produced by the mould Aspergillus flavus commonly found in peanuts, cottonseed, soybeans, wheat, barley, sorghum and nuts such as pistachios, almonds and cacao. Symptoms of poisoning include weight loss, loss of co-ordination, convulsions and death. It also damages the liver and causes liver tumours when consumed at low levels for a long period of time.

Afrikaans
Afrikaans is a language used in the Republic of South Africa.

Agar
Agar is a laxative substance obtained from seaweed.

Agenda
An agenda is a list of tasks.

Aggry Beads
Aggry Beads are glass beads prized by West African natives as ornaments and having magical and medicinal powers.

Agma
Agma is a tradename for calcined magnesite.

Agony Column
Originally, an agony column was a column in newspapers in which advertisements regarding missing relatives and friends, secret correspondence etc. were inserted. The name derived from the distress betrayed in many of the adverts. Today, an agony column is more associated with a column in a newspaper or magazine in which readers ask for advice on difficult and usually controversial situations (such as having an affair with a married person). The advice is given by an "agony aunt", a regular columnist working for the newspaper.

Agoraphobia
Agoraphobia is the fear of open spaces.

Agricultural Children Act
The Agricultural Children Act of 1873 prohibited the employment of children under eight years of age, and provided for the education of older children.

Agricultural Hall
Agricultural Hall is a building in Islington, London. Work commenced on it in 1861, and it opened in 1862 for an exhibition of dogs. It was constructed chiefly for the meetings of the Smithfield Club.

Aidx
AIDX is a derogatory term for IBM's perverted version of UNIX, AIX, especially for the AIX 3.? used in the IBM RS/6000 series. A victim of the dreaded "hybridism" disease, this attempt to combine the two main currents of the UNIX stream (BSD and USG UNIX) became a monstrosity to haunt system administrators' dreams. For example, if new accounts are created while many users are logged on, the load average jumps quickly over 20 due to a silly implementation of the user databases.

Air
The air is a mixture of gasses enveloping the earth.

Aircraft
An aircraft is a flying machine, a vessel which flies through the air rather than floats on water or travels along a road or rail.

Aisle
An aisle is a passage between rows of seats.

Albert Medal
The Albert Medal was a British decoration established in 1866 for gallantry in the saving of life.

Albert Memorial
The Albert Memorial is a memorial in Hyde Park, London. It was erected in memory of Prince Albert. It is an Eleanor cross, 45 meters high, embellished with statues and designed by Sir Georhe Gilbert Scott. It was completed in 1872 and contains a gilt statue of Prince Albert by Foley. It was unveiled on March the 9th 1876.

Albugo
Albugo is an affection of the eye, consisting of a white opacity in the cornea.

Albuminoids
The albuminoids are organic nitrogenous compounds chemically allied to the proteids, but differing from them and from one another in various ways. The chief recognised albuminoids are collagen, gelatin, keratin, elastin, ossein and chitin.

Alchemy
Alchemy was the medieval forerunner to chemistry. It was the supposed technique of transmuting base metals, such as lead and mercury, into silver and gold by the philosopher's stone, a hypothetical substance, to which was also attributed the power to give eternal life. This aspect of alchemy constituted much of the chemistry of the Middle Ages. More broadly, however, alchemy was a system of philosophy that dealt both with the mystery of life and the formation of inanimate substances. Alchemy was a complex and indefinite conglomeration of chemistry, astrology, occultism, and magic, blended with obscure and abstruse ideas derived from various religious systems and other sources. It was practised in Europe from ancient times to the Middle Ages but later fell into disrepute when chemistry and physics developed. Alchemy probably began in Egypt, where it is mentioned in very early records. Many legends developed regarding the origin of this mystical science, which is variously attributed to Hermes Trismegistus, to the fallen angels of the Book of Genesis, and yet again by revelation to Moses and Aaron. The origin through Hermes was most generally accepted, and has affected chemical language down to the present day (for example, hermetically sealed). During the 4th and 5th centuries the writings of the alchemists continued increasing until by the end of the 5th century speculative alchemy had reached its highest point in the Alexandrian schools. During the Islamic conquests, many Arabs and Persians became notable alchemists. One of the best known was Jabir ibn Hayyan, known to western Europe as Geber. His ideas were very similar to those of the old Alexandrian philosophers, and he also believed in the influence of the planets on metals. The theory of transmutation, which can be traced quite easily in the writings of the Greek philosophers, continued to exist amongst the alchemists of the Middle Ages and men such as St Albertus Magnus, Roger Bacon, and Vincent of Beauvais
all believed in it. Even well into the 17th century alchemistic ideas were still held, at least from the academic point of view, by the chemists of the period. Among them may be mentioned Johann Glauber, Robert Boyle, and, for some time Isaac Newton and Gottfried Leibniz, and even Dr Johnson, who was interested in chemistry.

Alcohol
Alcohol is a volatile liquid derived from hydrocarbons.

Alcoholic
see "alcohol"

Aldebaran
Aldebaran is the chief star of the constellation of Taurus.

Aldehyde
Aldehyde is a chemistry term applied to the compounds of alcohol intermediate between the alcohols and the acids.

Aldrin
see "Dieldrin"

Aldus Persuasion
Aldus Persuasion is a full-featured desktop-presentation product for the Mac that lets you create graphics presentations using slides, transparencies, speaker notes, audience handouts, and on-screen slide shows. It includes an outliner, freehand-drawing tools, and business-charting capabilities. presentations can be created from scratch, or can include charts created in a spreadsheet or any graphics imported from another package. Aldus Persuasion includes an outliner to begin creating presentations. Once the outliner and slide masters are set, the program automatically creates your slides. The outline text and slide text are hot linked, so changes made to one are automatically reflected in the other. Speakers notes can be created from the outline. Aldus Persuasion lets you create multiple masters for slides, notes, and handouts. You define page orientation, background colour and pattern, and the graphics to be placed on the master. You can add a title, body text, charts, tables, or organisation charts to the master. More than one master can be used in a presentation. This means that a company can intersperse master text slides, master chart slides and master table slides in a single presentation. New masters can be created based on existing ones. The drawing tools are very advanced and allow editing of all characteristics of an object. Although Aldus Persuasion does not do calculations, it includes powerful chart editing capabilities and provides full control over axes, tick marks, legend placement, formatting of axes, switching of axes, and numerical formats. Persuasion lets you import worksheets from spreadsheet programs such as Microsoft Excel and generate charts using the data. Aldus Persuasion outputs to a number of slide services as well as printers and film recorders compatible with the Apple System. The slide-show generator lets you set the delay between slides and layers on slides. You can set the show for full screen, partial screen, or continuous cycle,
where the show automatically repeats, or set it to stop after it has gone through the show once. You can also set the show to either automatic advance where you can set the timing, or manual where you click the mouse to move from slide to slide.

Ale
Ale is an alcoholic drink made from malt and hops.

Aleurometer
An aleurometer is a device used in bread making for measuring the quality of wheaten flour.

Alfa Sprint
The Alfa Sprint is a sporty front-wheel drive coupe automobile plagued by a poor quality body and powered by a 1500 or 1700 CC engine giving roughly 30 mpg.

Algebra
Algebra is a division of mathematics dealing with relations.

Algebraic
see "algebra"

Algin
Algin (Alginic Acid) is a substance resembling albumin, but not coagulated by heat. It is obtained from seaweed, chiefly the genera Fucus and Laminaria, as a precipitate after boiling with sodium carbonate and adding hydrochloric acid. It is used as a dressing for fabrics and as a thickening for soups and jellies.

Alginate
Alginate is an apparently safe derivative of kelp, it is used as a food additive to maintain the desired texture in dairy products, canned frosting, and other factory-made foods. Propylene glycol alginate, a chemically-modified algin, thickens acidic foods (soda pop, salad dressing) and stabilises the head in beer.

Alginic Acid
see "Algin"

Algol
Algol is a star in the constellation of Perseus. It was catalogued by Ptolemy as the lucida of the Gorgon. It is the model 'eclipse star' varying in brightness over a two day period through the interpositions of a revolving dark satellite. The light-changes of Algol were noticed by Montanari in 1669 and methodically observed and explained by Goodricke in 1783.
ALGOL is an algebraic computer language.

Algorithm
An algorithm is a set of rules.

Algraphy
Algraphy is a printing process in which aluminium plates are used.

Alibi
The plea of alibi in a criminal prosecution means that the person accused was elsewhere (alibi) at the time of the commission of the crime. If proved, it is conclusive, however it is a plea easily and frequently fabricated.

Alienation
In law, alienation is the transfer of the title to property from one person to another by conveyance, and not by inheritance.

Aliment
In Scottish law, aliment is the maintenance of children and other persons who are entitled to claim on the grounds of relationship or marriage.

Alimony
Alimony is an allowance made by a husband to a wife, or by a wife to a husband, in divorce proceedings.

Alkakarb
Alkakarb is a tradename for sodium bicarbonate.

Alkali
An alkali is a chemical substance.

Alkaloid
The alkaloids are nitrogenous organic substances having alkaline or basic properties. They occur in both animal and vegetable substances, and may be prepared artificially. Most alkaloids are white, odourless, crystalline solids composed of carbon, hydrogen, nitrogen and oxygen, but a few are liquids and contain no oxygen. They all combine with acids to form well-defined salts, but have few other properties in common, though many have an acrid, bitter taste and most are powerful poisons.

Alkane
The alkanes are the paraffin series of hydrocarbons.

Alkanes
see "alkane"

Alkanoyl
In chemistry, alkanoyl is the general name for an organic functional group R.CO-, where R represents hydrogen or an alkyl group.

Alkene
An alkene is a member of the ethylene series of hydrocarbons.

Alkyl
Alkyl refers to a substance which is derived from or related to the paraffin series of hydrocarbons.

Alkyloamides
Alkyloamides are groups of synthetic fatty acids designated as DEA, MEA, MIPA, and PEG. Used for thickening, gelling, emulsifying, emolliency, skin and hair conditioning, foam boosting, foam stabilizing, wetting, opacifying, lubricating, powder binding, skin protecting, fungicidal properties, and superfatting. They are found in shampoos, bubble baths, and liquid hand and body cleansers. They are harmful when contaminated by nitrosamines, and harmful to the environment.

All Souls' Day
All Souls' Day is a festival of the Roman Catholic Church on November the 2nd, offering prayers to the faithful dead. It was instituted in 998 in the monastery of Clugny.

Allantoin
Allantoin is a crystalline solid substance discovered by Vauquelin in 1790 in the foetal fluids of many animals. It is reported to have healing, soothing and anti-irritating properties. Today it is extracted from urea, which is derived from the urine of most animals, and from herbs like comfrey or uva ursi, and is used in cosmetics.

Allegretto
Allegretto is an indication of tempo in music. It is a diminutive of allegro and signifies a slower movement than allegro but not as slow as andante.

Allegro
Allegro is a musical term signifying a quick, lively rate of movement, nearly intermediate between andante and presto.

Allergy
An allergy is a hypersensitivity of body tissue to a substance.

Alley
An alley is a narrow street.

Allgemeine Zeitung
Allgemeine Zeitung is a German newspaper. It was founded in 1778 by Johann Cota in Stuttgart.

Allies
The Allies were various countries that fought the Axis forces in the Second World War.

Allopathy
Allopathy is the mode of curing diseases by using medicines which produce in the system a condition contrary to that of the disease. The term was first used by Hahnemann to indicate the methods of orthodox medicine.

Allotropism
In chemistry, allotropism is the property of certain elements of existing in more than one form, such as oxygen and ozone.

Alloy
An alloy is a mixture of a metal and other metals or non-metals.

Allspice
Allspice is a spice prepared from the dried berries of the evergreen pimento tree or West Indian pepper tree Pimenta dioica of the myrtle family, cultivated chiefly in Jamaica. It has an aroma similar to that of a mixture of cinnamon, cloves, and nutmeg.

Alluvium
Alluvium is river transported deposits of mud, sand and gravel which accumulate to form distinctive features such as levees, flood plains and deltas.

Allyl
Allyl is an unsaturated organic radical from which are derived an alcohol and other compounds. Allyl alcohol is prepared by heating glycerin and oxalic acid.

Alpenhorn
An alpenhorn is a long bugle-horn made of wood formerly used by Swiss peasants to communicate with each other over long distances.

Alpenstock
An alpenstock is a stout staff, iron-tipped, used by mountain climbers. The names of ascended peaks are often branded onto its shaft.

Alpha
Alpha is the first letter of the Greek alphabet.

Alpha hydroxy acids
Alpha hydroxy acids are a group of acids that appear naturally in fruit. They are used in toners, creams, and masks to exfoliate and moisturise the skin. They can be a skin irritant causing redness and rashes.

Alpha particle
In chemistry, an alpha particle is the positively charged nucleus of the helium atom.

Alpha Particles
Alpha Particles are the nuclei of the atom of helium, comprising two neutrons and two protons, and thus exhibiting a positive electric charge.

Alpha Rays
Alpha Rays are a stream of swiftly moving alpha particles. An alpha ray is capable of ionising gases and of producing fluorescence in certain substances.

Alpha-tocopherol
see "Vitamin E"

Alpha/three
Alpha/three is a file manager that uses the dBase III table and index format. It was a strong choice for companies which have standardised on dBase and have a lot of users who need to work with the data but are not dBase programmers. Although Alpha/three is a good complement to dBase lIl Plus, it has many features that make it a very good stand-alone file manager including data validation, a powerful report writer and a form letter generator which can insert variable text into standard form letters.

Alphabet
An alphabet is an ordered series of letters used in language.

Alpine Club
The Alpine Club was an English society formed in London in 1857 to bring together those people interested in mountain climbing.

Alpine Journal
The Alpine Journal was the magazine published by the Alpine Club. The magazine was founded in 1863.

Alprostadil
Alprostadil is a synthetic hormone used to induce labour (through ripening the cervix) in pregnant women. It is applied as a gel behind the cervix, which it is absorbed by and causes the cervix to dilate and contractions to occur. It carries with it the risk of distressing the baby which may not be able to cope with the sudden and violent contractions, and may also have the side effect of causing the woman to experience a long and agonising labour of pseudo-contractions before real contractions commence.

Altar
An altar is a block used for making offerings to a deity.

Alternating Current
Alternating current is electric current which changes direction rhythmically, rising from zero to a maximum in the positive direction, falling to zero again and then increasing to a maximum in the negative direction before returning again to zero, after which the cycle repeats. The number of cycles per second is the frequency of the alternating phenomenon. British domestic alternating current exhibits 50 cycles per second, where as American domestic alternating current exhibits 60.

Althing
The Althing is the parliament of Iceland, it was created in 928 on the lines of the previously existing Norse Thing and is the oldest parliamentary assembly in the world. It's modern form was constituted in 1874.

Altimeter
An altimeter is a device measuring altitude.

Altitude
Altitude is height above mean sea level.

Aluminium
Aluminium is a bluish-silver-white, malleable, ductile, light, trivalent metallic element with good electrical and thermal conductivity, high reflectivity, and resistance to oxidation and is the most abundant metal in the earth's crust occurring always in combination. It has the symbol Al.

Alundum
Alundum is a form of aluminium oxide used in the manufacture of thermionic valves for insulating the cathode heater from the tubular cathode.

Amalgam
An amalgam is an alloy of mercury. All metals except iron and platinum form amalgams. Used extensively in dentistry for filling teeth, amalgams were found in 1998 to damage the immune system and are likely to be one of the causes of AIDs.

Amaurosis
Amaurosis is an obsolete term for loss of sight. It became obsolete around 1900.

Amazon
The Amazon was a West India mail steam ship. She left Southampton on her first voyage on Friday 2nd of January 1852 and on Sunday morning, January 4th, she was destroyed by fire at sea, about 175 km west-south-west of Scilly. Of 161 persons on board 102 perished.

Ambaree
Ambaree is a fibre similar to jute and largely used in India. It is obtained from Hibiscus cannabinus.

Amber
Amber is fossilised resin.

Ambergris
Ambergris is a substance derived from the intestine of the sperm whale and used in perfume.

Ambidextrous
Ambidextrous is having the facility to use the left hand as effectively as the right.

Ambient Noise
Ambient Noise is constant noise present in all forms of telecommunications paths.

Ambo
In the early Christian Church, an ambo was a reading desk or pulpit from which the lessons were read or the sermon preached.

Ambrosian Library
The Ambrosian Library is a famous library in Milan, founded in 1602 by Carlos Borromeo, and named in honour of St Ambrose, the patron saint of the city.

Ambulance
An ambulance is a wagon, litter or other means of transport used for the conveyance of the sick and disabled.

Ambulatory
In architecture, an ambulatory is any part of a building intended for walking around a central space or shrine, such as the aisles of a cathedral or church. The term is used for the lateral or flanking porticos of an ancient Greek temple, and for the cloister of a monastery.

Amenorrhoea
Amenorrhoea is a medical condition being the absence or suspension of menstruation.

American
American is a term referring to someone or something which comes from, or is found in, America.

American Wire Gauge
American Wire Gauge (AWG) is descriptive of the diameter of wire conductors, particularly in twisted pair cabling; The AWG has an effect on the transmission capacity and distance a given wire can offer. Internationally, wire size is described in millimetric diameter, except in England, where the weight in pounds per mile is used.

Americium
Americium is a synthetic chemical element with the symbol Am that is the most frequently used element for superconducting devices. It is artificially produced from plutonium, and is used commercially in gauges, distance-sensing devices, and smoke alarms. Americium was first synthesised in a nuclear reactor in 1944 by Glenn Seaborg, Ralph James, Leon Morgan, and Albert Ghiorso.

Amharic
The Amharic language is a language spoken in Ethiopia since the 13th century when it succeeded Geez or Ethiopic. It is Semitic in origin and written right to left.

Amice
An amice is a white linen vestment worn by Roman Catholic and many Anglican priests when officiating at Mass or Holy Eucharist.

Amicus curiae
Amicus curiae is a legal term for a barrister advising the court in a legal case as a neutral person, not representing either side. In England and Wales, for example, where the public interest is concerned, the Attorney General (or his or her representative) may be asked to express an opinion. Professional bodies such as the Law Society may be represented in order to give an opinion on matters affecting their members. In the USA, a person with a strong interest in or views on the subject matter of an action, but who is not a party to it, may be given the court's permission to act as amicus curiae, usually only in matters of broad public interest.

Amides
The amides are a group of organic compounds derived from ammonia by the replacement of a portion of the hydrogen by an acid radical. they are usually solid substances, are neutral to litmus, but act as bases to acids, with which they form salts. Treated with phosphoric anhydride, they are dehydrated, and become nitriles; while if they are boiled with aqueous caustic potash they give off ammonia, and leave the potash in combination with the acid.

Amido-benzene
see "Aniline"

Amidogen
Amidogen is the group NH2. It is known only in combination forming amides with acid radicals, and amines with alkyls. The products are generally known as amido compounds.

Amine
Amines are a class of compounds derived from ammonia by the replacement of one or more hydrogen atoms with organic groups.

Amines
Amines are compounds derived from ammonia by replacing the hydrogen with one or more alkyls or alcohol radicals; they are primary, secondary or tertiary according to the number of hydrogen atmos replaced. The amines are mostly volatile, and act as bases, forming salts with acids in a similar manner to ammonia.

Amino acid
Amino acids are fundamental constituents of all proteins.

Amino acids
see "amino acid"

Ammeter
An ammeter is a device for measuring electrical current.

Ammonia
Ammonia (Spirits of Hartshorn) is a colourless gas. Formulae NH3. It occurs in nature in minute quantities in the atmosphere and in natural waters, being derived from the decomposition of nitrogenous organic substances. It appears to have been known to the ancients, but was obtained by Priestley in 1774 and its exact composition was demonstrated by Berthollet in 1785.

Ammonite
Ammonite is an explosive composed of pure ammonium nitrate and ntro-napthalene; formerly used in coal mining.

Ammonium
Ammonium is the basic radical of ammonium salts. It is comprised of one atom of nitrogen and four atoms of hydrogen.

Ammonium Chloride
Ammonium Chloride (Sal Ammoniac) is a fibrous mass prepared by neutralising ammonia with hydrochloric acid. It is used in medicine, dyeing and soldering. It has the formulae NH4Cl.

Ammonium Sulphate
Ammonium sulphate is a brown-grey to white crystalline solid which is used primarily as a nitrogen fertilizer. It is a particularly good fertilizer for rice. It is also used as a general-purpose food additive and as an additive to supply nitrogen in fermentation processes. It is produced by the reaction of by-product ammonia from coke ovens with sulphuric acid. Ammonium sulphate is a powerful oxidiser. When heated, the sulphate decomposes at 100 degrees C and yields ammonium bisulphate. When heated to decomposition, it emits very toxic fumes of nitrous oxide, ammonia, and sulphur trioxide. Ammonium sulphate is insoluble in alcohol and acetone. If mixed with oxidisers, ammonium sulphate is an explosion hazard during a fire. Ammonium sulphate is also known as ammonium hydrogen sulphate, diammonium sulphate, and sulphuric acid, diammonium salt.

Amniocentesis
Amniocentesis is a medical procedure sometimes performed during pregnancy to help determine the health and maturity of an unborn baby. It involves the withdrawal and study of a small amount of the amniotic fluid that surrounds the foetus in the mother's uterus. Laboratory tests on the fluid, which contains cells shed by the foetus, enable detection of many serious disorders that may affect the foetus. Such disorders include Down's syndrome and spina bifida. Amniocentesis involves little risk to either the mother or the foetus. Amniocentesis is mostly performed around the 16th week of pregnancy on 'at risk' mothers. These include those more than 35 years of age and those with genetic disorders in the family. If tests reveal serious abnormality, likely to cause death or pronounced handicap, the parents may choose to end the pregnancy. Otherwise, doctors can plan ahead for early treatment, either in the womb or at birth. If there is some medical reason for delivering a baby before it is due to be born, amniocentesis may be performed later in pregnancy. In this case, tests show whether the baby is likely to survive outside the womb. An obstetrician performs amniocentesis with the aid of ultrasound which enables the obstetrician to monitor the position of the foetus while inserting a long hollow needle through the mother's abdominal wall and into the uterus. The obstetrician then withdraws a small amount of amniotic fluid, which is sent away for testing.

Amoebic dysentery
Amoebic dysentery is an illness caused by the pathogen Entamoeba histolytica which is transmitted by the fecal-oral route. Cysts are excreted in the faeces of an infected individual or carrier and ingested through faecally-contaminated food, water, objects, etc. After excystation, the trophozoites penetrate the walls of the large intestines causing ulceration and frequently causing the symptoms of dysentery. Involvement of the liver and other organs may occur if the protozoan invades the blood.

Amok
Amok is a Malay term denoting a sudden frenzy which seizes an individual, sometimes as a result of intoxicants, but often unaccountably.

Amoroso
Amoroso is a musical term indicating a tender, delicate style.

Amorphous
Amorphous is a term applied to substances devoid of characteristic shape, or of different properties in different directions, in contradistinction to crystalline bodies.

Amoxicillin Trihydrate
Amoxicillin trihydrate is a drug used to treat systemic infections and acute and chronic urinary tract infections. It has the possible side effects of: Nausea, vomiting, diarrhoea, hypersensitivity (rash) and itching.

Amp
see "ampere"

Ampere
The ampere is the fundamental unit of measurement of electrical current.

Amphetamine
Amphetamine is a drug that induces sleeplessness.

Amphitheatre
An amphitheatre is a circular or ovular arena surrounded by tiers of seats.

Ampicillin Trihydrate
Ampicillin trihydrate is a drug used to treat systemic infections and acute and chronic urinary tract infections. It has the possible side effects of: Nausea, vomiting, diarrhoea, glossitis (inflammation of the tongue), stomatitis (inflammation of the mouth), hypersensitivity (rash) and itching.

Amplifier
An amplifier is an apparatus capable of producing a magnified version of the input signal.

Amplitude
Amplitude refers to magnitude or size. It is the voltage or power of an electronic signal.

Amplitude Modulation
Amplitude Modulation is modifying a ''carrier'' signal by varying its instantaneous power to represent the information it carries. Most commonly called ''AM''.

Amyl
Amyl is a chemical alcohol radical. It was first isolated by Edward Frankland in 1849.

Amyl Nitrate
Amyl nitrate is a powerful poison with a specific action on the heart and blood-vessels. It is inhaled in small doses in certain diseases of the heart and in asthma. Nowadays, Amyl nitrite is used as a narcotic and sold under the name 'poppers'. It is popular amongst club goers, and particularly the gay community where it contributes to the high instances of AIDs by its adverse effect upon the immune system.

Amylene
Amylene is a colourless, mobile liquid first procured by Balard of Paris in 1844 by distilling fusel oil with chloride of zinc. The vapour was employed instead of chloroform first by Snow in 1856.

Amylum
Amylum is an alternative name for starch.

Anabaptist
The Anabaptists were a 16th century Christian sect, so called because they rejected infant baptism in reference of adult baptism. They were a fanatical sect led by Nicholas Storck who intended reorganisation of German society based upon civil and political equality.

Anabaptists
see "Anabaptist"

Anacrotism
Anacrotism is an irregularity of the pulse.

Anaemia
Anaemia is the medical condition of lacking red blood cells.

Analeptic
Analeptic is a term applied to those drugs or other means which are used to restore strength after disease.

Analgesic
An analgesic is a pain reliever.

Analog Loopback
Analog Loopback (ALB) is connecting a received analog signal to the return transmitting path; a common test method for locating transmission problems in data transmission systems.

Analog Signal
An analog signal is a signal in the form of a continuous varying in step with the actual transmitted information; attempts to transmit an exact replica of the inputted signal down a communications channel.

Analog Transmission
Analog Transmission is communications by transmission of continuously varying representations of the input signal, as compared to coded words in digital transmission.

Analogue Computer
An analogue computer is a computing device in which the variables in a given problem are represented by physical quantities, such as lengths, pressures, electric charges etc., the calculations consisting in the manipulation and measurement of these quantities, the values of which may change continuously.

Anatomical Alloy
Anatomical alloy is a fusible alloy consisting of 53.5 per cent bismuth, 19 percent tin, 17 per cent lead and 10.5 per cent mercury.

Anatrofin
Anatrofin is an anabolic steroid. It causes increased protein synthesis and amino acid consumption, androgensisis, catabolism, and gluticocototitosis. It is used for sports performance enhancement, relief and recovery from common injuries, rehabilitation, weight control, anti-insomnia, and regulation of sexuality, aggression, and cognition.

Anaxvar
Anaxvar is an anabolic steroid. It causes increased protein synthesis and amino acid consumption, androgensisis, catabolism, and gluticocototitosis. It is used for sports performance enhancement, relief and recovery from common injuries, rehabilitation, weight control, anti-insomnia, and regulation of sexuality, aggression, and cognition.

Anchor
An anchor is a heavy implement used for securing boats at sea.

Anchor Ice
Anchor Ice is a rare phenomena occurring in rivers where the current is too strong for the formation of ice on the surface, but where ice forms on the bottom. This ice may encircle a stone or other object (such as a ship's anchor, hence the name), causing it to float to the surface when sufficient ice has formed.

Ancient Mariner
The Ancient Mariner is a poem by Coleridge, published in 'Lyrical Ballads' in 1798. The idea appears to have been taken from Captain Shelvocke's 'Voyage Round the World' published in 1757.

Andante
Andante is a musical term denoting a movement somewhat slow, graceful, distinct and soothing.

Andricite
Andricite is a tradename for anhydrous calcium sulphate.

Androgen
Androgen is a term embracing any of the male sex hormones, substances that induce and maintain secondary sex characteristics in males. The principal androgens are testosterone and androsterone. They are found in the male testes and adrenal glands, in which they are produced; in the blood, in which they circulate; and in the urine, in which they are excreted. Androgens function principally, beginning at puberty, in the stimulation of such secondary sex characteristics as development of the genital organs and maturation of sperm, growth of body hair, and changes in the larynx that lower the voice. They also account for the growth of muscle mass and bone tissue in the developing male.

Anemometer
An anemometer is a device for measuring the strength and velocity of wind. It was invented by Wolfius in 1709. The hemispherical cup anemometer (still used today) was invented in 1846 by Robinson and consists of four hemispherical cups which rotate horizontally with the wind, and a combination of wheels which record the number of revolutions in a given time.

Angina
Angina is sense of suffocating or pain in the chest caused by a lack of blood being supplied to the heart muscle, thereby causing insufficient oxygen to be supplied to the heart. The cause of the pain is suspected to be a build-up of irritant acids in the heart muscle deprived of oxygen, not unlike the ache one feels in other muscles during and after strenuous exercise.

Angiosperm
An angiosperm is a flowering plant in which the seeds are enclosed within an ovary which ripens into a fruit.

Angle Modulation
Angle Modulation is refers to the change of angle of a signal that occurs in Frequency Modulation or Phase Modulation communications systems; usually analog.

Anglicanism
Anglicanism is a family of Christian churches including the Church of England, the US Episcopal Church, and those holding the same essential doctrines, that is the Lambeth Quadrilateral 1888 Holy Scripture as the basis of all doctrine, the Nicene and Apostles' Creeds, Holy Baptism and Holy Communion, and the historic episcopate.

Anglo-Japanese Treaty
The Anglo-Japanese Treaty was a treaty signed by Great Britain and Japan on January 30th 1902, by which the two powers agreed to safeguard their common interests in China and Korea. In the event of one of them being at war with a foreign power, the other would maintain a strict neutrality, but would assist her ally if a second foreign power joined the first. The treaty also stated that neither party would enter into agreements without the consent of the other and would confide fully in the other if common interests were endangered. The treaty was agreed for five years.

Angostura
Angostura is a flavouring prepared from oil distilled from the bitter, aromatic bark of either of two South American trees, Galipea officinalis or Cusparia trifoliata, of the rue family. It is blended with herbs and other flavourings to give angostura bitters, which was first used as a stomach remedy and is now used to season food, fruit, and alcoholic drinks. It takes its name from the port of Angostura (now Ciudad Bolívar) in Venezuela.

Angst
Angst is an emotional state of anxiety without a specific cause.

Angstrom Unit
The Angstrom Unit is a unit of length employed for the measurement of the wavelengths of light and X-rays etc.

Anhydride
Anhydride is an oxide of an element or organic radical, capable of combining with water to form an acid. Nearly all the non-metallic elements, as well as several of the metallic elements form anhydrides. Thus sulphuric anhydride, SO3, with water makes sulphuric acid.

Anhydrous
In chemistry, anhydrous refers to something which is without water.

Aniline
Aniline (Phenylamine or amido-benzene) is an oily liquid occurring in coal-tar and made by the reduction of nitro-benzene and used in the manufacture of chemicals, dyes and drugs. It was discovered in 1826 by Unverdorben among the products of distillation of indigo. In 1856 Bechamp obtained it from nitro-benzene.

Aniline Red
see "Magenta"

Anion
An anion is a negatively charged ion which, in an electrolyte or in a gas-filled space, travels towards the positive electrode or anode.

Anker
The anker was a measurement used in Britain and Germany for beer, spirits and the like. It was equivalent to 8.5 gallons. The Scottish anker contained 20 Scottish pints.

Annadrol
Annadrol is an anabolic steroid. It causes increased protein synthesis and amino acid consumption, androgensisis, catabolism, and gluticocototitosis. It is used for sports performance enhancement, relief and recovery from common injuries, rehabilitation, weight control, anti-insomnia, and regulation of sexuality, aggression, and cognition.

Annuity Tax
Annuity tax was a tax levied by Charles I to provide stipends for ministers in Edinburgh and Montrose, it caused much disaffection and was abolished in 1860, and other provisions made for the purpose. These proved equally unpopular and their abolition was provided for by an act passed in 1870.

Anode
An anode is the principal positive electrode by which the current leaves an electrolyte, electron tube etc.

Anorthoscope
The anorthoscope is an optical apparatus described by Carpenter in 1868. In it distorted figures lose their distortion when in rapid motion.

Anosmia
Anosmia is the inability to smell.

ANSI
ANSI is the American National Standards Institute. The official repository of standards for the USA.

Answer Back
Answer Back is an electrical and/or visual indication to the call originating end that the call terminating end is on the line. First associated with the International Telex network, answerbacks are also recommended in CCITT-standard fax machines and are provided in most PC data communications software packages.

Anthelmintics
Anthelmintics are remedies which kill or expel intestinal worms. Vermicides kill the worms, vermifuges expel them.

Anthraquinone
Anthraquinone is a yellow, crystalline solid obtained by oxidising anthracene with chromic acid mixture. It is used in the manufacture of alizarin and its derivatives.

Anthrax
Anthrax is a disease of sheep and cattle transmittable to humans.

Anthropology
Anthropology is the study of humans as animals.

Anti-Corn Law League
The Anti-Corn Law League was an organisation formed in 1838 with its headquarters at Manchester, to effect the repeal of the corn laws in Britain. It was led by Cobden, Bright, Villiers, Joseph Hume and Roebuck. The league held meetings, oratories and published a paper (the League) and was an organised, aggressive and effective body. With its objectives achieved by the royal assent given to repeal the corn laws in 1846 to 1849 the league was dissolved.

Anti-rentism
Anti-rentism was a movement amongst the leaseholders of certain counties in New York State, USA during 1839 to 1847 to resist the feudal dues appertaining to the Dutch manorial and patroonship rights still remaining, though virtually abolished in 1775. In 1839 the heirs of one of the largest landowners in Albany county endeavoured to evict those tenants who had not paid the feudal rents. The tenants resisted, the movement spread, ant-rent associations were formed and disturbances occurred. Repressive measures were adopted, and the resistance was put down. In 1846 feudal tenures of all kinds were abolished, and agricultural leases were limited to a maximum period of twelve years.

Anti-Vivisection Society
The Anti-Vivisection Society was formed in London in 1876 to oppose vivisection.

Antiarin
Antiarin is a poison exuded by the Upas tree and used by Javan natives for tipping arrows.

Antibiotic
An antibiotic is a substance that inhibits the growth of micro organisms.

Antidote
An antidote is a drug used to counteract poison.

Antifebrin
Antifebrin was a trade name for acetanilide.

Antimony
Antimony is a brittle, silver-white, pentavalent metal element with the symbol Sb.

Antioxidants
Antioxidants are substances that slow the breakdown of nutrients and counteract the destructive effect of free radicals (chemically reactive compounds) in the body. There are several types which include vitamins A, E, C complex, and B complex, the minerals selenium and zinc, and the synthetic compounds BHT and BHA. Vitamins A, C, and E as well as BHA, and BHT are used as preserving agents in cosmetics.

Antipyrin
Antipyrin (Phenazone) is a synthetic drug formerly used in medicine as an antipyretic and analgesic in place of quinine.

Antipyrine
Antipyrine is an artificial alkaloid obtained from coal-tar and discovered in 1883 by Knorr. It was said to be a remedy for sea-sickness, a substitute for quinine and a source of aniline colours.

Antiseptic
An antiseptic is a substance which counteracts blood or tissue poisoning caused by bacteria (sepsis).

Anvil
An anvil is a block used by metal smiths.

Anxiolytic
An anxiolytic is a drug used to reduce anxiety.

Apache Dance
The apache dance is a fast and violent dance in French vaudeville, supposedly between a Parisian gangster and his girl.

Aparejo
An aparejo is a kind of American packsaddle made of stuffed leather cushions.

Apartheid
Apartheid is the policy of racial segregation of people. It was first established in South Africa in 1948 restricting the rights of non-whites and establishing blacks only homelands.

Aperture
In photography, an aperture is an opening through which light passes through the lens to strike the film.

Aphasia
Aphasia is difficulty in reading, writing and speaking due to brain damage.

Aphelion
The aphelion is the point at which an object travelling around the sun in an elliptical orbit is at its furthest from the sun.

Apocrenic Acid
Apocrenic acid is a compound discovered by Berzelius in soil containing rotting vegetable substances, and in the yellow deposit of chalybeate waters. It is formed by oxidation of crenic acid.

Apogee
Apogee is an astronomical term referring to the position in the orbit of the Moon which is farthest from the Earth. Opposite to Perigee.

Apollo Asteroid
The apollo asteroids are a group of small asteroids whose orbits cross that of the earth. They were first discovered in 1932 and then lost until 1973.

Apollo Project
The Apollo Project was the US space project to land a person on the moon. It was achieved by Apollo 11 in July 1969.

Aposiopesis
Aposiopesis is an abrupt breaking away from a sentence and leaving it unfinished for the sake of greater effect.

Apostle Spoons
Apostle spoons were spoons with figures of the apostles crowning the handles. They were given as baptismal presents during the 16th and 17th centuries.

Appalachian Tea
Appalachian Tea (Carolina Tea, Black Drink) is a north American substitute for traditional tea.

Applause II
The replacement for Draw Applause, Applause II by Ashton Tate is a business graphics, charting, drawing, and presentation package all in one. It can be used to create slides, do on screen presentations, or create annotated charts. The picture Window includes drawing tools such as text, lines, circles, arcs, boxes, and polygons which can be used to annotate charts or create freehand illustrations. Images can be copied, moved deleted, rotated, sized, and stretched. Objects can be customised with fill colours, patterns, and line widths. A small clip-art library of images is also available. The images are object-oriented so you can edit the individual elements. The program includes some interesting and artistic special effects. For example, you can create colour blends by picking two colours and the starting points for each in an enclosed area. The product automatically fills the colours so they blend into the centre of the object you are filling. This creates the illusion of three-dimensional objects. You can create slide shows with Applause II although there is no runtime slide show utility. Links can be established between Applause II and any data file, including Lotus 1-2-3, dBase, any Master product, or Framework. This means that presentations can be created more easily and efficiently than if you needed to key data in from scratch.

Appleton Layer
see "F Layer"

Applique
Applique is a type of embroidery used to create pictures or patterns by applying pieces of material to a background fabric.

Aqua
Aqua is another word for water, now commonly used on cosmetic product ingredients lists.

Aqua Fortis
see "Nitric Acid"

Aqua Sambuci
Aqua sambuci is the scientific name for Elder Flower Water, prepared with 1 part elder flower to 5 parts water. It is used in medicine as an eye and skin lotion.

Aqua Tofana
Aqua Tofana was a poisonous liquid, invented by Teofania di Adamo. After her death in 1633 her daughter, Giulia Tofana, sold the liquid at Rome and Naples in vials under the title 'Manna of St Nicholas of Bari'. It was a clear, colourless, tasteless liquid of which only a very small quantity was sufficient to produce death under symptoms which did not readily arouse suspicion of poisoning.

Aquatint
Aquatint is a method of print-making which was popular in the 18th century. Prints are produced imitating the broad effects of India ink and sepia drawings. Areas, not lines, are bitten in by dilute acid on a copper plate covered with black resin on which the design has already been traced. The process was designed by Abbe St Non in the 18th century and perfected by Jean Baptiste le Prince also in the 18th century. By the end of the 19th century aquatint was virtually obsolete except for the tints in some coloured pictures.

Aqueduct
An aqueduct is a channel in which water flows by gravity.

Aqueous
Aqueous refers to a solution based upon water.

Araf
Araf is the Muslim purgatory, a raised wall of separation between heaven and hell.

Arc Wars
The arc wars were computer "wars" over which archiving program one should use. The first arc war was sparked when System Enhancement Associates (SEA) sued PKWare for copyright and trademark infringement on its ARC program. PKWare's PKARC outperformed ARC on both compression and speed while largely retaining compatibility (it introduced a new compression type that could be disabled for backward-compatibility). PKWare settled out of court to avoid enormous legal costs (both SEA and PKWare are small companies); as part of the settlement, the name of PKARC was changed to PKPAK. The public backlash against SEA for bringing suit helped to hasten the demise of ARC as a standard when PKWare and others introduced new, incompatible archivers with better compression algorithms.

Archeozoic
The archeozoic period was the first geological period. It was characterised by an absence of animal life and extensive volcanic activity.

Archers Ales
Archers Ales is an English beer brewing company of Wiltshire. They were established in 1979.

Archipelago
An archipelago is a group of islands.

Arcnet
Arcnet is a LAN architecture developed by Datapoint Corporation featuring low cost for connection of groups of (Async) terminals to a (mini) computer within a premises.

Are
The are is a French measurement of one square meter.

Area Code
Area Code is colloquial term for a three digit number identifying one of more than 150 geographic areas of North America providing for Direct Distance Dialling on the public telephone network system. This entire system of numbers is under the umbrella of Country Code 01 in the World Numbering Plan of the CCITT.

Areometer
An areometer is an instrument for measuring the density and specific gravity of liquids.

Arete
An arete is a steep angular mountain ridge.

Argon
Argon is a colourless, odourless, gaseous element found in the air and volcanic gases, and is used especially as a filler for electric bulbs and electron tubes. It has the symbol Ar.

Aries
Aries is one of the signs of the zodiac. Represented by the ram.

Armagnac
Armagnac is a deep-coloured brandy named after the district of Armagnac in Gascony, South-West France, where it is produced.

Armature
An armature is a part of an electrical motor or dynamo.

Armour
Armour is a protective covering.

Arms
Arms is a military term referring to weapons.

Army
An army is an organised fighting force.

Arq
Arq is telegraphic code signal for "Automatic Repeat Request," a time-honoured method of telegraphic error correction upon which most data transmission error correction is based. ARQ receivers check for errors and initiate an order to retransmit data blocks determined to be corrupted in transmission.

Arrack
Arrack is a coarse liquor manufactured in the East Indies from a large variety of substances, for example fermented rice or coconut juice. Arrack is transparent and the colour of straw and has a peculiar but agreeable taste and contains bewteen 52 and 54% alcohol.

Arroba
Arroba was a Spanish unit of weight equal to about 25 lbs. It was also used in South and Central America, where it was equivalent to about 32 lbs.

Arsenal
An arsenal is a place for storing weapons.

Arshin
Arshin is a Russian unit of measurement equivalent to 28 inches.

Artane
Artane is a tradename for trihexyphenidyl hydrochloride

Arundel Footslogger
Arundel Footslogger is a pale, straw-coloured beer from the Arundel Brewery.

ASCII
ASCII is the American Standard Code for Information Interchange.
The most common code used for asynchronous data transmission by minicomputers and personal computers. Derived from the TWX code of the Bell Model 28 teleprinter, expanded to use all possible character combinations.
ASCII consists of 7 information bits with an 8th parity bit for error checking; numerous variations exist, for example use of the 8th bit in personal computers to extend the code with a number of graphics, special language characters and diacritical marks. Many common carrier data services cannot transmit the 8th bit needed to use that common PC extension of ASCII's alphabet.

Ascorbic acid
see "Vitamin c"

Ash Vine
Ash Vine is an English beer brewing company of Somerset. They were established in 1987.

Ash Wednesday
Ash Wednesday is the first day of lent, the seventh Wednesday before Easter.

Aspartame
Aspartame (Equal, NutraSweet), is an artifical sweetner made up primarily of two amino acids. Some people have reported adverse behavioral effects (dizziness, hallucinations, headache) after drinking diet soda, but such reports have not been confirmed in controlled studies.

Asphalt
Asphalt is a material used for road coverings.

Aspirin
Aspirin is an analgesic.

ASR
ASR is telegraphic name for an "Automatic Send/Receive" terminal station, typically one that has storage for outbound messages and holds them until called upon by the communications network to send.

Assay
Assay is the testing of an alloy or an ore to determine the proportion of a given metal. An assay officer is someone who certifies the fineness of gold, silver and platinum.

Assize of Battle
Assize of Battle was by the old law of England, a means whereby a man charged with murder might fight with the appellant, thereby to make proof of his guilt or innocence. The law was struck off the statute book in 1819.

Astatine
Astatine is a radioactive halogen element which was discovered by bombarding bismuth with alpha particles and is also released by radioactive decay. It has the symbol At.

Astern
Astern is a nautical term meaning behind the ship.

Asteroid
An asteroid is a minor planetary body.

Asthma
Asthma is a disease characterised by breathing difficulties.

Astramorph
Astramorph is a tradename for morphine sulphate.

Astringent
An astringent is a substance which contracts tissues, chiefly by coagulating albumin. When applied in the form of lotions or ointments, they reduce the congestion of mucous membranes and thus assist in the healing of wounds and ulcers.

Astrology
Astrology is the science of the relationship between events and the stars.

Astronomy
Astronomy is the study of celestial bodies.

Asynchronous
Asynchronous refers to occurring without central control or in an unpredictable time interval between successive elements; the typical mode of telegraphy, minicomputers and personal computers; requires s transmission of ''start'' and ''stop'' bits to provide decoding synchronisation at the receiver.

Ataxia
Ataxia is a lack of coordination in the muscles. It is a symptom of damage to part of the central nervous system. Locomotor ataxia involves a lack of balance, or equilibrium. Patients must stand on a broad base, eyes open, or they will sway or even fall. The swaying increases if they shut their eyes. Ataxia has many causes, locomotor ataxia may be due to syphilis for example. Many diseases that damage the central nervous system may cause ataxia, including tumours of the cerebrum or cerebellum, some deficiency diseases, and diseases of the spinal cord. Ataxia may also result from overuse of such drugs as barbiturates or alcohol.

Atmolysis
Atmolysis is a method of separating the constituent gases of a compound gas (such as air) by causing it to pass through a vessel of porous material (such as graphite). The process was discovered by Graham and made known in 1863.

Atmosphere
The atmosphere is the gaseous envelope surrounding a planet, such as that which surrounds the earth which is comprised of nitrogen, oxygen, argon carbon dioxide, helium, water vapour and other gases.

Atoll
An atoll is a circular, or horseshoe-shaped coral island surrounding a lagoon with one or more openings to the sea.

Atom
An atom is the smallest quantity of a chemical element which can enter into combination or take part in a chemical reaction.

Atomic number
In chemistry, an atomic number is a number, characteristic of an atom, that represents the number of protons in the nucleus of the atom. It indicates the location of an element in the periodic table.

Atomic weight
In chemistry, atomic weight is the relative weight of an atom referred to carbon, whose weight has been arbitrarily set at 12.01115.

Atoms
see "atom"

Atrium
The atrium was the entrance hall to a Roman house.

Atropine
Atropine is the poisonous alkaloid found in deadly nightshade.

Attar
Attar (Otto of Roses) is a perfume which consists of the volatile or essential oil distilled from certain varieties of rose.

Attenuation
Attenuation is a term denoting a decrease in power between that transmitted and that received due to loss through equipment, lines, or other transmission devices. Usually expressed as a ratio in dB (decibels). - Synonym: Loss; Antonym: Gain

Attenuator
In electronics, an attenuator is a network used to deliberately reduce the input signal to some piece of apparatus, or to reduce the degree of amplification of signals of particular frequencies.

Atutti
see "tarot Cards"

Aucassin et Nicolette
Aucassin et Nicolette is a celebrated French romance of the 12th century, written in alternate prose and assonant verse of seven syllables. It recounts the love of Aucassin, son of the Count of Beaucaire, for Nicolette, the captive daughter of the king of Carthage.

Audiometer
An audiometer is a device for measuring the sense of hearing. It was invented by Professor Hughes in 1879.

Audiphone
The audiphone was an early hearing-aid invented by Rhodes and improved in 1880 by Colladon. It consisted of a thin sheet of hard ebonite rubber or cardboard placed next to the teeth through which and other bones sound vibrations are conveyed to the auditory nerve.

August
The month of august was the sixth month of the Roman calendar and was originally called Sextilis, by a decree of the senate it received its present name in honour of Augustus Caesar in 8 BC.

Aune
see "Ell"

AutoCAD
AutoCAD Release 10 is a two and three-dimensional computer aided drafting and design system. The product lets you define screens and optional pull-down menus and create parts libraries by drawing them, so the system can be geared to a specific requirement. The product is a general-purpose system suitable for a wide variety of applications including architectural and landscape drawings; drafting for mechanical, electrical, chemical, structural, and civil engineering; and printed circuit design. Drawing and editing features include move, copy, modify, dimension, scale, mirror, hatch, rotate, fill, and erase objects in a drawing. Repetitive patterns such as brick walls, memory arrays, or office components can be generated automatically. Colours and an unlimited number of layers may be used, allowing selective viewing or plotting of drawings as if on transparent overlays. The full bidirectional zoom facility allows you to work at any level of detail. The ratio between the largest and smallest objects in a drawing can be over a trillion to one. An alignment grid can be displayed. Distances and areas can be calculated and displayed. Three-dimensional drawing capability, AutoCAD's most notable feature, lets you represent an object so it can be seen from any angle. AutoCAD Release 10 also features associative dimensioning, which automatically updates the dimensions of a drawing whenever an object is scaled, stretched, or rotated. Release 10 allows you to construct objects in CAD much as you would build a structure. The approach is modular; that is, each piece of the final drawing is created as a separate object. To build an office building, you define the plane for the front of the building, move to that plane or a view of that plane to draw, then move to the side defining a new plane, and soon until a complete two or three-dimensional structure stands. An analogy to drafting does not work because a drafting table cannot be situated in a three-dimensional plane. AutoCAD
lease 10 supports the Intel Above Board, which increases the speed at which large, complex drawings can be created and edited. It supports the Initial Graphics Exchange Standard (ICES, Version 2.0) for both input and output, so translations can be made between AutoCAD Release 10 and other systems supporting IGES. You can transfer AutoCAD Release 10 drawing files among four operating systems: PC or MS DOS, Sun UNIX, DEC VMS, and Apollo AEGIS.

Autodesk Animator
Autodesk Animator is an animation program that lets you create desktop videos for promotion and training. The program includes a number of animation techniques, painting functions, text effects, and file-import capabilities that provide a workbench for creating impressive diskette-based presentations. Autodesk Animator incorporates five types of animation. Each is specifically designed to make creating and displaying animation sequences as impressive and easy as possible. The program provides traditional cell-by-cell animation capabilities. This technique displays a sequence of individual cells or images in rapid succession resulting in movement. Optical animation is best suited for animations where objects swoop across the screen. This technique uses complex combinations of spline paths and full 3D transformations along with other optical functions to maximise this type of effect. Polymorphic tweening is an animation technique used to blend between two completely different shapes. It can be combined with optical animation to add threedimensional effects. Colour cycling transforms the colour of various screen locations. Titling provides full text animation for incorporating text in any part of a desktop video. Titling effects include multiple-direction scrolling and type-on, where each letter of words appears in rapid succession. Paint functions combine image processing inks with over 20 tools for detailed image creation and editing. The image processing inks affect the dispersion and quality of onscreen colours. The inks can be applied to saturate, strengthen, and define colours and create effects such as opaque, soften, gloss, glaze, emboss, scrape-through, sheen, and highlight. The combination of Animator's painting tools and image processing inks lets you control the sharpness, illumination, intensity, and glow of on-screen presentation colours more effectively than with any other PC product.

Autoroute
Autoroute is a map information system built using data from Ordnance Survey. It allows quick planning of the most suitable route between points in Great Britain. To use Autoroute, the user first needs to tell the package the travelling speed of the vehicle. Then, enter the start point and the desired destination, along with other places to visit - or places to avoid. Autoroute will calculate the quickest and the shortest routes, which can be displayed as a colour map and then printed. A set of written directions can also be printed, including such detail as "At Gillette Comer, turn left onto A310 to Richmond." The estimated journey time and total mileage are also calculated.

AutoSketch
AutoSketch is software for drawing. As easy to use as painting software, it includes many CAD features. However, unlike typical painting software, AutoSketch keeps track of objects. This means that shapes do not get lost in a sea of dots. When an object is manipulated, it maintains its integrity as a complete unit. The product was designed for users with less demanding drawing requirements such as office layouts, simple technical drawings, and flowcharts. AutoSketch is the best starting point for individuals who may be interested in upgrading to AutoCAD later. In addition, AutoCAD users may find AutoSketch useful in the early drawing stages. AutoSketch can draw lines, arcs, circles, points, polygons and spline curves (free-form shapes). All basic drawing shapes can be moved, copied, stretched, rotated, mirrored, or scaled. For example, by pointing and clicking, you can create an office layout where walls and furniture can be moved or adjusted on-screen. AutoSketch uses a mouse with pull-down menus and dialog boxes. AutoSketch includes other CAD features such as dimensioning and measuring, snap and ortho alignment, layers, and line types. Text can be added at any point, at any angle, and can be any height or width. AutoSketch also allows you to insert another AutoSketch drawing, so you can create a library of objects for future use.

Auxin
Auxin is a hormone that promotes stem and root growth in plants. Auxins influence many aspects of plant growth and development, including cell enlargement, inhibition of development of axillary buds, tropisms, and the initiation of roots. Synthetic auxins are used in rooting powders for cuttings, and in some weedkillers, where high auxin concentrations cause such rapid growth that the plants die. They are also used to prevent premature fruitdrop in orchards. The most common naturally occurring auxin is known as indoleacetic acid, or IAA. It is produced in the shoot apex and transported to other parts of the plant.

Avenin
Avenin is a stimulating nitrogenous alkaloid found in oats.

Avobenzone
Avobenzone is a sunscreen ingredient that protects against ultraviolet A (UVA) rays.

Avogadro's law
In chemistry, Avogadro's law is the law which states that equal volumes of all gases, at the same temperature and pressure, contain the same number of molecules.

Avoirdupois
The avoirdupois scale is a measurement of weight.

Awk
Awk is a UNIX interpreted language for massaging text data developed by Alfred Aho, Peter Weinberger, and Brian Kernighan (the name is from their initials). It is characterised by a C-like syntax, a declaration-free approach to variable typing and declarations, associative arrays, and field-oriented text processing.

Axe
An axe is a metal tool for chopping and cleaving.

Axis PC
The Axis PC is a computer from Atlantic Systems based upon the 333mhz Intel Celeron Processor and supplied with 64 mb of RAM, a 4.3 gb hard drive, an ATI 4 mb 3d AGP graphics card, CD-ROM player, sound card, 3.5 inch floppy disk drive and a 56K voice and fax modem.

Azathioprine
azathioprine is a synthetic drug that suppresses the normal immune responses of the body and is administered orally during and after organ transplantation and also in certain types of anaemia and rheumatoid arthritis. It has the formula C9H7N7O2S.

Azedarach
Azedarach is the astringent bark of the chinaberry tree. It was formerly used in medicine as an emetic and cathartic.

Azide
In chemistry, an azide is a compound containing the monovalent group -N3 or the monovalent ion N3-.

Azilian
Azilian describes a Palaeolithic culture of Spain and Southwest France that can be dated to the 10th millennium BC. It is characterised by flat bone harpoons and schematically painted pebbles.

Azine
In chemistry, an azine is any organic compound having a six-membered ring containing at least one nitrogen atom.

Azobenzene
Azobenzene is a yellow or orange crystalline solid used mainly in the manufacture of dyes. It has the formula C6H5N:NC6H5.

Azoimide
Azoimide is a compound of hydrogen and nitrogen. It is a very explosive gas obtained from organic sources such as benzoyl-glycollic acid and hippuric acid.

Copyright 1997,1998 Servile Software Enquiries to Matthew Probert

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