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ALCOHOL

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Originally appearing in Volume V01, Page 527 of the 1911 Encyclopedia Britannica.
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ALCOHOL , in See also:

commerce, the name generally given to " See also:spirits of See also:wine "; in systematic organic See also:chemistry it has a wider meaning, being the generic name of a class of compounds (hydroxy See also:hydrocarbons) of which See also:ordinary alcohol (specifically See also:ethyl alcohol) is a typical member (see See also:ALCOHOLS). The word " alcohol " is of Arabic origin, being derived from the particle al and the word See also:kohl, an impalpable See also:powder used in the See also:East for See also:painting the eyebrows. For many centuries the word was used to designate any See also:fine powder; its See also:present-See also:day application to the product of the See also:distillation of wine is of comparatively See also:recent date. Thus See also:Paracelsus and Libavius both used the See also:term to denote a fine powder, the latter speaking of an alcohol derived from See also:antimony. At the same See also:time Paracelsus uses the word for a volatile liquid; alcool or alcool vini occurs often in his writings, and once he adds " id est vino ardente." Other names have been in use among the earlier chemists for this same liquid. Eau de See also:vie (" See also:elixir of See also:life ") was in use during the 13th and 14th centuries; Arnoldus Villanovanus applied it to the product of distilled wine, though not as a specific name. Ordinary alcohol, which we shall frequently refer to by its specific name, ethyl alcohol, seldom occurs in the See also:vegetable See also:kingdom; the unripe seeds of Heracleum giganteum Ethyt and H. Sphondylium contain it mixed with ethyl alcot,ol. butyrate. In the See also:animal kingdom it occurs in the urine of diabetic patients and of persons addicted to alcohol. Its important source lies in its formation by the " spirituous " or alcoholic See also:fermentation " of saccharine juices. The mechanism of alcoholic fermentation is discussed in the See also:article FERMENTATION, and the manufacture of alcohol from fermented liquors in the article SPIRITS. The qualitative See also:composition of ethyl alcohol was ascertained by A.

L. See also:

Lavoisier, and the quantitative by N. T. de See also:Saussure in 18o8. See also:Sir See also:Edward See also:Frankland showed how it could be derived from, and converted into, ethane; and thus determined it to be ethane in which one See also:hydrogen See also:atom was replaced by a hydroxyl See also:group. Its constitutional See also:formula is therefore CH3•CH2.OH. It may be synthetically prepared by any of the See also:general methods described in the article ALCOHOLS. Pure ethyl alcohol is a colourless, See also:mobile liquid of an agreeable odour. It boils at 78.3° C. (760 mm.); at -9o° C. it is a thick liquid, and at -13o° it solidifies to a See also:white See also:mass. Its high coefficient of thermal expansion, coupled with its See also:low freezing point, renders it a valuable thermometric fluid, especially when the temperatures to be measured are below -390 C., for which the See also:mercury thermometer cannot be used. It readily inflames, burning with a See also:blue smokeless See also:flame, and producing See also:water and See also:carbon dioxide, with the See also:evolution of See also:great See also:heat; hence it receives considerable application as a See also:fuel. It mixes with water in all proportions, the mixing being attended by a See also:con-See also:traction in See also:volume and a rise in temperature; the maximum contraction corresponds to a mixture of 3 molecules of alcohol and r of water.

Commercial alcohol or " spirits of wine " contains about :90 % of pure ethyl alcohol, the See also:

remainder being water. This water cannot be entirely removed by fractional distillation, and to prepare anhydrous or " See also:absolute " alcohol the commercial product must be allowed to stand over some dehydrating See also:agent, such as See also:caustic See also:lime, baryta, anhydrous See also:copper sulphate, &c., and then distilled. See also:Calcium. chloride must not be used, since it forms a crystalline See also:compound with alcohol. The quantity of alcohol present in an aqueous See also:solution is determined by a comparison of its specific gravity with See also:standard tables, or directly by the use of an alcoholometer, which is a See also:hydrometer graduated so as to read per cents by See also:weight (degrees according to See also:Richter) or volume per cents (degrees according to See also:Tralles). Other methods consist in deter-See also:mining the vapour tension by means of the vaporimeter of See also:Geissler, or the boiling point by the ebullioscope. In the See also:United Kingdom " See also:proof spirit " is defined' as having a specific gravity at 51° of 12/13 (.92308) compared with water at the same temperature. The " quantity at proof " is given by the formula: See also:Etymology. quantity of See also:sample X (degrees over or under proof + xoo) divided by roo. The presence of water in alcohol may be detected in several ways.. Aqueous alcohol becomes turbid when mixed with See also:benzene, carbon disulphide or See also:paraffin oil; when added to a solution of See also:barium See also:oxide in absolute alcohol, a white precipitate of barium hydroxide is formed. A more delicate method consists in adding a very little See also:anthraquinone and See also:sodium See also:amalgam; absolute alcohol gives a See also:green coloration, but in the presence of See also:minute traces of water a red coloration appears. Traces of ethyl alcohol in solutions are detected and estimated by oxidation to acetaldehyde, or by See also:conversion into See also:iodoform by warming with See also:iodine and See also:potassium hydroxide.

An alternative method consists in converting it into ethyl benzoate by shaking with benzoyl chloride and caustic soda. Alcohol is extensively employed as a solvent; in fact, this constitutes one of its most important See also:

industrial applications. It dissolves most organic compounds, resins, hydrocarbons, fatty acids and many metallic salts, sometimes forming, in the latter See also:case, crystalline compounds in which the ethyl alcohol plays a role similar to that of water of See also:crystallization. This fact was first noticed by T. See also:Graham, and, although it was at first contradicted, its truth was subsequently confirmed. In general, gases dissolve in it more readily than in water; roo volumes of alcohol dissolve 7 volumes of hydrogen, 25 volumes of See also:oxygen and 16 volumes of See also:nitrogen. Potassium and sodium readily dissolve in ethyl alcohol with the See also:production of alcoholates of the formula C2 H5 OK(Na). Reactions. These are voluminous white powders. Sulphuric See also:acid converts it into ethyl sulphuric acid (see See also:ETHER), and See also:sulphur trioxide gives carbyl sulphate. The phosphorous haloids give the corresponding ethyl haloid. Ethyl chloride (from the See also:phosphorus chlorides and alcohol) is an ethereal liquid boiling at 12.5° C., soluble in alcohol, but sparingly so in water.

Oxidation of ethyl alcohol gives acetaldehyde and acetic acid. See also:

Chlorine oxidizes it to acetaldehyde, and under certain conditions See also:chloral (q.v.) is formed. In almost all countries heavy taxes are levied on manufactured alcohol mainly as a source of See also:revenue. In the United Kingdom Industrial the See also:excise See also:duty is eleven shillings per proof See also:gallon of akonoi. alcohol, while the customs duty is eleven shillings and fivepence; the magnitude of these imposts may be more readily understood when one remembers that the proof gallon See also:costs only about sevenpence to manufacture. The great importance of alcohol in the arts has necessitated the introduction of a duty-See also:free product which is suitable for most industrial purposes, and at the same time is perfectly unfit for beverages or See also:internal application. In the United Kingdom this " denaturized" alcohol is known as methylated spirit as a distinction from pure alcohol or " spirits of wine." It was first enacted in 1855 that methylated Methylated spirit, a specific mixture of pure alcohol and See also:wood- spirlt. See also:naphtha, should be duty-free; the present See also:law is to be found in the Customs and Inland Revenue See also:Act of 189o, and the See also:Finance Act (See also:sect. 8) of 1902. From 1858 to 1861 methylated spirit was duty-free when it was required for manufacturing processes, and the methylation or " denaturizing was carried out in accordance with a prescribed See also:process. During the next three decades (1861-1891) the law was extended, and methylated spirit was duty-free for all purposes except for use as beverages and internal medicinal applications. This spirit (" unmineralized methylated spirit ") consisted of 90 parts of alcohol of 6o-66 over-proof (91-95 % of pure alcohol) and 10 parts of wood-naphtha. It was found, however, that certain classes were addicted to drinking this mixture, and since 1891 the See also:sale of such spirit has been confined to manufacturers who must See also:purchase it in bulk from the " methylators." For See also:retail purposes the " ordinary " methylated spirit is mixed with •357 % of See also:mineral naphtha, which has the effect of rendering it quite undrinkable.

The Finance Act of 1902 allows a manufacturer to obtain a Iicense which permits the use of duty-free alcohol, if he can show that such alcohol is absolutely essentialfor the success of his business, and that methylated spirit , is unsuitable. Notwithstanding. this permission there have been many agitations on the See also:

part of chemical manufacturers to obtain a less restricted use of absolute alcohol, and in 1905 an Industrial Alcohol See also:Committee was appointed to receive See also:evidence and See also:report as to whether any modification of the present law was advisable. In the United States the same question was considered in 1896 by a See also:Joint Select Committee on the use of alcohol in the manufactures and arts. Reference should be made to the reports of these committees for a full See also:account of the use, manufacture and See also:statistics of " denaturized " spirits in various See also:European countries. In See also:Germany, the use of duty-free spirit is only allowed to See also:state and municipal hospitals, and state scientific institutions, and for the manufacture of fulminates, fuzes and smokeless powders. The duty-free " denaturized " spirits may be divided into two groups—" completely denaturized " and " incompletely denaturized." In the first See also:category there are two varieties:—(r) A mixture of roo litres of spirit and 21 litres of a mixture of 4 parts of wood-naphtha and r of See also:pyridine bases; this spirit, the use of which is practically limited to See also:heating and See also:lighting purposes, may be mixed with 50 grs. of See also:lavender or See also:rosemary, in See also:order to destroy the noxious odour of the pyridine bases. (2) A mixture of zoo litres of spirit, 11 litres of the naphtha-pyridine mixture described above, 4 litre of methyl See also:violet solution, and from 2 to 20 litres of benzol; this fluid is limited to See also:combustion in See also:motors and agricultural engines. The second category, or " incompletely denaturized" spirits, include numerous mixtures. The "general" mixture consists of roo litres of spirit, and 5 litres of wood spirit or 2 litre of pyridine. Of the " particular " varieties, we can only See also:notice those used in the See also:colour See also:industry. These consist of roo litres of spirit mixed with either to litres of sulphuric ether, or r litre of benzol, or i litre of See also:turpentine, or •025 litre of animal oil. The See also:German regulations are apparently based on a keen appreciation of the fact that while one particular denaturizing agent may have little or no effect on one industry, yet it would be quite fatal to the success of another; there is consequently a great _ choice of denaturizing agents, and in certain cases it is sufficient to mix the alcohol with a reagent necessary for the purpose in See also:hand, or even with a certain amount of the final product, it being only necessary to satisfy the state that the spirit is not available as a beverage.

In See also:

France, the general denaturizing agent is wood-spirit of at least 58 over-proof, and containing 25 % of See also:acetone and 2.5 % of "impurites pyrogen6es"; ro litres of this spirit denaturizes roo litres of alcohol. This mixture is supplied to manufacturers and corresponds to the See also:British unmineralized methylated spirit; but the regulations are more stringent. When sold for lighting and heating purposes, it is further admixed with o•5 % of heavy. benzene boiling at 15o°-200° C. Provisions are also made for See also:special denaturizing processes as in Germany. In See also:America the internal revenue tax on denaturized alcohol (formerly duty-free only to scientific institutions) was removed by See also:Congress in 1906 (act of See also:June 7th). See also:Pharmacology, See also:Toxicology and See also:Therapeutics of Alcohol. Alcohol is of great medicinal value as a solvent, being used to See also:form solutions of alkaloids, resins, volatile See also:oils, iodoform, &c. In strength of about xo % and upwards it is an antiseptic. If applied to the skin it rapidly evaporates, thereby cooling the skin and diminishing the amount of sweat excreted. This refrigerant and anhidrotic See also:action is employed to soothe many forms of headache by bathing the forehead with eau de See also:Cologne. If, on the other hand, the alcohol be rubbed into the skin, or if its evaporation be prevented—as by a See also:watch-glass—it absorbs water from the tissues and thus hardens them. Thoroughly rubbed into the skin alcohol dilates the See also:blood-vessels and produces a mild See also:counter-irritant effect.

Many alcoholic liniments are therefore employed for the See also:

relief of See also:pain, especially See also:muscular pains, as in See also:lumbago and. other forms of so-called " muscular See also:rheumatism." Given internally in small quantities and in sufficient dilution, alcohol causes See also:dilatation of the gastric blood-vessels, increased secretion of gastric juice, and greater activity in the movements of the muscular layers in the See also:wall of the See also:stomach. It also tends to lessen the sensibility of the stomach and so may relieve gastric pain. In a 5o % solution or stronger—as when neat See also:whisky is taken—alcohol precipitates the See also:pepsin which is an essential of gastric digestion, and thereby arrests this process. The desirable effects produced by alcohol on the stomach are See also:worth obtaining only in cases of acute diseases. In chronic disease and in See also:health the use of alcohol as an aid to digestion is without the support' of clinical or laboratory experience, the beneficial action being at least neutralized by undesirable effects produced elsewhere. The continued use of large doses of alcohol produces chronic See also:gastritis, in which the continued irritation has led to overgrowth of connective See also:tissue, See also:atrophy of the gastric glands and permanent ,cessation of the gastric functions. A single dose of concentrated alcohol (e.g. See also:brandy) produces very valuable reflex effects, the See also:heart beating more rapidly and forcibly, and the blood-pressure rising. Hence the immediately beneficial effect produced in the cases of " fainting " or See also:syncope. After absorption, which is very rapid, alcohol exerts a marked action upon the blood. The oxygen contained in that fluid, and destined for See also:consumption by the tissues, is retained by the See also:influence of alcohol in its See also:combination with the haemoglobin or colouring See also:matter of the red blood corpuscles. Hence the diminished oxidation of the tissues, which leads to the See also:accumulation of unused See also:fat and so to the obesity which is so often seen in those who habitually take much alcohol. The See also:drug exerts a noteworthy action upon the See also:body-temperature.

As it dilates the blood-vessels of the skin it increases the subjective sensation of warmth. The actual consequence, however, is that more heat than before is necessarily lost from the See also:

surface of the body. Alcohol also diminishes the oxidation which is the See also:main-source of the body-heat. It follows that the drug is an antipyretic, and it is hence largely used in fevers as a means of reducing the temperature. This reduction of the temperature, carried to an undesirable extreme, is the See also:reason why the See also:man who has copiously consumed spirits " to keep out the See also:cold " is often visited with See also:pneumonia. The largest amount of alcohol that can be burnt up within the healthy body in twenty-four See also:hours is xa oz., but it must be consumed in great dilution and divided into small doses taken every four hours. Otherwise the alcohol will for the most part leave the body unused in the urine and the expired See also:air. In See also:fever the case is different. The raised temperature appears to facilitate the oxidation of the substance, so that quantities may be taken and completely utilized which would completely intoxicate the individual had his temperature been normal. It follows that alcohol is a See also:food in fever, and its value in this regard is greatly increased by the fact, that it requires no See also:primary digestion, but passes without changes, and without needing See also:change, to the tissues which are to use it. According to Sir See also:Thomas See also:Fraser nothing else can compete with alcohol as a food in desperate febrile cases, and to this use must be added its antipyretic See also:power already explained and its action as a soporific. During its See also:administration in.febrile cases the drub must be most carefully watched, as its action may prove deleterious to the See also:nervous See also:system and the circulation in certain classes of patient.

The state of the See also:

pulse is the best criterion of the action of alcohol in any given case of fever. The toxicology of alcohol is treated in other articles. It includes acute alcoholism (i.e. See also:intoxication), chronic alcoholism, See also:delirium tremens, and all the countless pathological changes—extending to every tissue but the bones, and especially marked in the nervous system—which alcohol produces. (See See also:DRUNKENNESS;DELIRIUM). After See also:death the presence of alcohol can be detected in all the body fluids. Its especial See also:affinity for the nervous system is indicated by the fact that, when all traces of it have disappeared elsewhere, it can still be detected with ease in the cerebro-See also:spinal fluid.

End of Article: ALCOHOL

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