Now, by Gilpin's tables this indicates a compound of 100 grains of alcohol 0.825, and 85 grains of water. But by Lowitz's table in Crell's Annals, the above specific gravity corresponds to 48 alcohol of 0.791 at the temperature of 68°, united to 52 of water, and cooled down to 60. Equal weights of that strong alcohol and water, give, at 60°, a specific gravity of 0.9175. By the Act of Parliament of 1762, the specific gravity of proof was fixed at 0.916. It is at present to water as 12 to 13, or 0.923. See DISTILLATION.* The most remarkable characteristic property of alcohol, is its solubility or combination in all proportions with water; a property possessed by no other combustible substance, *except the acetic spirit obtained by distilling the dry acetates.* When it is burned in a chimney which communicates with the worm-pipe of a distilling apparatus, the product, which is condensed, is found to consist of water, which exceeds the spirit in weight about one-eighth part; *or more accurately, 100 parts of alcohol, by combustion, yield 136 of water. If alcohol be burned in closed vessels with vital air, the product is found to be water and carbonic acid. Whence it is inferred that alcohol consists of hydrogen, united either to carbonic acid or its acidifiable base; and that the oxygen uniting on the one part with the hydrogen, forms water; and on the other with the base of the carbonic acid, forms that acid. * The most exact experiments on this subject are those recently made by M. de Saussure. The alcohol he used had, at 62.8°, a specific gravity of 0.8302; and by Richter's proportions, it consists of 13.8 water, and 86.2 of absolute alcohol. The vapour of alcohol was made to traverse a narrow porcelain tube ignited, from which the products passed along a glass tube about six feet in length, refrigerated by ice. A little charcoal was deposited in the porcelain, and a trace of oil in the glass tube. The resulting gas being analyzed in an exploding eudiometer, with oxygen, was found to resolve itself into carbonic acid and water. Three volumes of oxygen disappeared for every two volumes of carbonic acid produced; a proportion which obtains, in the analysis by oxygenation of olefiant gas. Now, as nothing resulted but a combustible gas of this peculiar constitution, and condensed water equal to 8 of the original weight of the alcohol, we may conclude, that vapour of water and olefiant gas are the sole constituents of alcohol. Subtracting the 13.8 per cent. of water in the alcohol at the beginning of the experiment, the absolute alcohol of Richter will consist of 13.7 hydrogen, 51.98 carbon, and 34.32 oxygen. Hence M. Gay-Lussac infers, that alcohol, in vapour, is composed of one volume olefiant gas, and one volume of the vapour of water, condensed by chemical affinity into one volume. $464 The sp. gr. of olefiant gas is 0.97804 Of aqueous vapour is 0.62500 Sum- 1.60304 And alcoholic vapour is = 1.6133 These numbers approach nearly to those which would result from two prime equivalents of olefiant gas, combined with one of water; or ultimately, three of hydrogen, two of carbon, and one of oxygen.* A considerable number of the uses of this fluid as a menstruum, will pass under our observation in the various articles of this work. The mutual action between alcohol and acids produces a light, volatile, and inflammable oil, called ether. See ETHER. Pure alkalis unite with spirit of wine, and form alkaline tinctures. Few of the neutral salts unite with this fluid, except such as contain ammonia. The carbonated fixed alkalis are not soluble in it. From the strong attraction which exists between alcohol and water, it unites with this last in saline solutions, and in most cases precipitates the salt. This is a pleasing experiment, which never fails to surprise those who are unacquainted with chemical effects. If, for example, a saturated solution of nitre in water be taken, and an equal quantity of strong spirit of wine be poured upon it, the mixture will constitute a weaker spirit, which is incapable of holding the nitre in solution; it therefore falls to the bottom instantly, in the form of minute crystals. The degrees of solubility of many neutral salts in alcohol have been ascertained by experiments made by Macquer, of which an account is published in the Me Tartrate of potash, 0.42 It appears from the experiments of Kirwan, that dried muriate of magnesia dissolves more abundantly in strong than in weak alcohol. 100 parts of specific gravity 0.900, dissolve 21.25; of 0.848, 23.75; of 0.834, 36.25; and of 0.817, 50 parts. The same holds to a more limited extent with acetate of lime; 2.4 grains being soluble in 100 of the first alcohol, and 4.88 in 100 of the last. The other salts which he tried dissolved more sparingly in the stronger than in the weaker alcohol. The temperature of the spirit was generally 60°. All deliquescent salts are soluble in al cohol. Alcohol holding the strontitic salts in solution, gives a flame of a rich purple. The cupreous salts and boracic acid give a green; the soluble calcareous, a reddish; the barytic, a yellowish. For the effect of other salts on the colour of the flame, see a preceding table. The alcohol of 0.825 has been subjected to a cold of - 91° without congealing. But Mr. Hutton has given, in the Edinburgh Encyclopædia, article Cold, an account of his having succeeded in solidifying it by a cold of - 110°. The alcohol he employed had a density of 0.798 at 609. His process has been kept secret. The boiling point of alcohol of 0.825 is 176°, Alcohol of 0.810 boils at 173.5°. For the force of its vapour at different temperatures, and its specific heat, see VAPOUR. M. Gay-Lussac having shown that this liquid is a compound of olefiant gas and water, potassium ought to disengage from it, hydrogen and olefiant gas. In the absolute alcohol of Richter there is no water, independent of that which is essential to its constitution. See FERMEN TATION. When chlorine is made to pass through alcohol in a Woulfe's apparatus, there is a mutual action. Water, an oily looking substance, muriatic acid, a little carbonic acid, and carbonaceous matter, are the products. This oily substance does not redden turnsole, though its analysis by heat shows it to contain muriatic acid. It is white, denser than water, has a cooling taste analogous to mint, and a peculiar, but not ethereous odour. It is very soluble in alcohol, but scarcely in water. The strongest alkalis hardly operate on it. It was at one time maintained, that alcohol did not exist in wines, but was generated and evolved by the heat of distillation. On this subject M. Gay-Lussac made some decisive experiments. He agitated wine with litharge in fine powder, till the liquid became as limpid as water, and then saturated it with subcarbonate of potash. The alcohol immediately separated and floated on the top. He distilled another portion of wine in vacuo, at 59o Fahr. a temperature considerably below that of fermentation. Alcohol came over. Mr. Brande proved the same position by saturating wine with subacetate of lead, and adding potash. MM. Adam and Duportal have substituted for the redistillations used in converting wine or beer into alcohol, a single process of great elegance. From the capital of the still a tube is led into a large copper recipient. This is joined by a second tube, to a second recipient, and so on through a series of four vessels, arranged like a Woulfe's apparatus. The last vessel communicates with the worm of the first re frigeratory, This, the body of the still and the two recipients nearest it, are charged with the wine or fermented liquor. When ebullition takes place in the still, the vapour issuing from it communicates soon the boiling temperature to the liquor in the two recipients. From these the volatilized alcohol will rise and pass into the third vessel, which is empty. After communicating a certain heat to it, a portion of the finer or less condensable spirit will pass into the fourth, and thence, in a little, into the worm of the first refrigeratory. The wine round the worm will likewise acquire heat, but more slowly. The vapour that in that event may pass uncondensed through the first worm, is conducted into a second, surrounded with cold water. Whenever the still is worked off, it is replenished by a stop-cock from the nearest recipient, which, in its turn, is filled from the second, and the second from the first worm tub. It is evident, from this arrangement, that by keeping the 3d and 4th recipients at a certain temperature, we may cause alcohol, of any degree of lightness, to form directly at the remote extremity of the apparatus. The utmost economy of fuel and time is also secured, and a better flavoured spirit is obtained. The arrière gout of bad spirit can scarcely be destroyed by infusion with charcoal and redistillation. In this mode of operating, the taste and smell are excellent, from the first. Several stills on the above principle have been constructed at Glasgow for the West India distillers, and have been found extremely advantageous. The excise laws do not permit their employment in the home trade.* If sulphur in sublimation meet with the vapour of alcohol, a very small portion combines with it, which communicates a hydrosulphurous smell to the fluid. The increased surface of the two substances appears to favour the combination. It had been supposed, that this was the only way in which they could be united; but M. Favre has lately asserted, that, having digested two drams of flowers of sulphur in an ounce of alcohol, over a gentle fire not sufficient to make it boil, for twelve hours, he obtained a solution that gave twenty-three grains of precipitate. A similar mixture left to stand for a month in a place exposed to the solar rays, afforded sixteen grains of precipitate; and another, from which the light was excluded, gave thirteen grains. If alcohol be boiled with one-fourth of its weight of sulphur for an hour, and filtered hot, a small quantity of minute crystals will be deposited on cooling; and the clear fluid will assume an opaline hue on being diluted with an equal quantity of water, in which state it will pass the filter, nor will any sediment be deposited for several hours. The alcohol used in the last-mentioned experiment did not exceed .840. Phosphorus is sparingly soluble in alcohol, but in greater quantity by heat than in cold. The addition of water to this solution affords an opaque milky fluid, which gradually becomes clear by the subsidence of the phosphorus. Earths seem to have scarcely any action upon alcohol. Quick-lime, however, produces some alteration in this fluid, by changing its flavour and rendering it of a yellow colour. A small portion is probably taken up. Soaps are dissolved with great facility in alcohol, with which they combine more readily than with water. None of the metals, or their oxides, are acted upon by this fluid. Resins, essential oils, camphor, bitumen, and various other substances, are dissolved with great facility in alcohol, from which they may be precipitated by the addition of water. From its property of dissolving resins, it becomes the menstruum of one class of varnishes. See VARNISH. Camphor is not only extremely soluble in alcohol, but assists the solution of resins in it. Fixed oils, when rendered drying by metallic oxides, are soluble in it, as well as when combined with alkalis. Wax, spermaceti, biliary calculi, urea, and all the animal substances of a resinous nature, are soluble in alcohol; but it curdles milk, coagulates albumen, and hardens the muscular fibre and coagulum of the blood. The uses of alcohol are various. As a solvent of resinous substances and essential oils, it is employed both in pharmacy and by the perfumer. erfumer. When diluted with an equal quantity of water, constituting what is called proof spirit, it is used for extracting tinctures from vegetable and other substances, the alcohol dissolving the resinous parts, and the water the gummy. From giving a steady heat without smoke when burnt in a lamp, it was formerly much employed to keep water boiling on the tea-table. In thermometers for measuring great degrees of cold, it is preferable to mercury, as we cannot bring it to freeze. It is in common use for preserving many anatomical preparations, and certain subjects of natural history; but to some it is injurious, the molluscæ for instance, the calcareous covering of which it in time corrodes. It is of considerable use too in chemical analysis, as appears under the different articles to which it is applicable. From the great expansive power of alcohol, it has been made a question, whether it might not be applied with advantage in the working of steam engines. From a series of experiments made by Betancourt, it appears, that the steam of alcohol has, in all cases of equal temperature, more than double the force of that of water; and that the steam of alcohol at 174° F. is equal to that of water at 2129: thus there is a considerable diminution of the consumption of fuel, and where this is so expensive as to be an object of great importance, by contriving the machinery so as to prevent the alcohol from being lost, it may possibly at some future time be used with advantage, if some other fluid of great expansive power, and inferior price, be not found more economical. It was observed at the beginning of this article, that alcohol might be decomposed by transmission through a red-hot tube: it is also decomposable by the strong acids, and thus affords that remarkable product, ETHER and OLEUM VINI. ALE. See BEER. ALEMBIC, or STILL. This part of chemical apparatus, used for distilling or separating volatile products, by first raising them by heat, and then condensing them into the liquid state by cold, is of extensive use in a variety of operations. It is described under the article LABORATORY. ALEMBROTH SALT. Corrosive muriate of mercury is rendered much more soluble in water, by the addition of muriate of ammonia. From this solution crystals are separated by cooling, which were called sal alembroth by the earlier chemists, and appeared to consist of ammonia, muriatic acid, and mercury. ALGAROTH (POWDER OF). Among the numerous preparations which the alchemical researches into the nature of antimony have afforded, the powder of algaroth is one. When butter of antimony is thrown into water, it is not totally dissolved; but part of the metallic oxide falls down in the form of a white powder, which is the powder of algaroth. It is violently purgative and emetic in small doses of three or four grains. See ANTIMONY. ALKAHEST. The pretended universal solvent, or menstruum, of the ancient chemists. Kunckel has very well shown the absurdity of searching for a universal solvent, by asking, " If it dissolve all substances, in what vessels can it be contained?" ALKALESCENT. Any substance in which alkaline properties are beginning to be developed, or to predominate, is termed alkalescent. The only alkali usually observed to be produced by spontaneous decomposition is the volatile; and from their tendency to produce this, some species of vegetables, particularly the cruciform, are styled alkalescent, as are some animal substances. See FERMENTATION (PUTRID), * ALKALI. A term derived from kali the Arabic name of a plant, from the ashes of which one species of alkaline substance can be extracted. Alkalis may be defined, those bodies which combine with acids, so as to neutralize or impair their activity, and produce salts. Acidity and alkalinity are therefore two correlative terms of one species of combination. When Lavoisier introduced oxygen as the acidifying principle, Morveau proposed hydrogen as the alkalifying principle, from its being a constituent of volatile alkali or ammonia. But the splendid discovery by Sir H. Davy, of the metallic bases of potash and soda, and of their conversion into alkalis, by combination with oxygen, has banished for ever that hypothetical conceit. It is the mode in which the constituents are combined, rather than the nature of the constituents themselves, which gives rise to the acid or alkaline condition. Some metals, combined with oxygen in one proportion, produce a body possessed of alkaline properties, in another proportion of acid properties. And on the other hand, ammonia and prussic acid prove that both the alkaline and acid conditions can exist independent of oxygen. These observations by generalizing our notions of acids and alkalis, have rendered the definitions of them very imperfect. The difficulty of tracing a limit between the acids and alkalis is still increased, when we find a body sometimes performing the functions of an acid, sometimes of an alkali. Nor can we diminish this difficulty by having recourse to the beautiful law discovered by Sir H. Davy, that oxygen and acids go to the positive pole, and hydrogen, alkalis, and inflammable bases to the negative pole. We cannot in fact give the name of acid to all the bodies which go to the first of these poles, and that of alkali to those that go to the second; and if we wished to define the alkalis by bringing into view their electric energy, it would be necessary to compare them with the electric energy which is opposite to them. Thus we are always reduced to define alkalinity by the property which it has of saturating acidity, because alkalinity and acidity are two correlative and inseparable terms. M. Gay-Lussac conceives the alkalinity which the metallic oxides enjoy to be the result of two opposite properties, the alkalifying property of metal, and the acidifying of oxygen, modified both by the combination and by the proportions. The alkalis may be arranged into three classes: 1st, Those which consist of a metallic basis combined with oxygen. These are three in number, potash, soda and lithia. 2d, That which contains no oxygen, viz. ammonia. 3d, Those containing oxygen, hydrogen, and carbon. In this class we [19] VOL. 1, have aconita, atropia, brucia, cicuta, datura delphia, hyosciama, morphia, strychnia, and perhaps some other truly vegetable alkalis. The order of vegetable alkalis may be as numerous as that of vegetable acids. The earths, lime, barytes, and strontites were enrolled among the alkalis by Fourcroy; but they have been kept apart by other systematic writers, and are called alkaline earths. Besides neutralizing acidity, and thereby giving birth to salts, the first four alkalis have the following properties: 1st, They change the purple colour of many vegetables to a green, the reds to a purple, and the yellows to a brown. If the purple have been reddened by acid, alkalis restore the purple. 2d, They possess this power on vegetable colours after being saturated with carbonic acid, by which criterion they are distinguishable from the alkaline earths. 3d, They have an acrid and urinous taste. 4th, They are powerful solvents or corrosives of animal matter; with which, as well as with oils in general, they combine, so as to produce neutrality. 5th, They are decomposed, or volatilized, at a strong red heat. 6th, They combine with water in every proportion, and also largely with alcohol. 7th, They continue to be soluble in water when neutralized with carbonic acid; while the alkaline earths thus become insoluble. It is needless to detail at length Dr. Murray's speculations on alkalinity. They seem to flow from a partial view of chemical phenomena. According to him, either oxygen or hydrogen may generate alkalinity, but the combination of both principles is necessary to give this condition its utmost energy. "Thus the class of alkalis will exhibit the same relations as the class of acids. Some are compounds of a base with oxygen; such are the greater number of the metallic oxides, and probably of the earths. Ammonia is a compound of a base with hydrogen. Potash, soda, barytes, strontites, and probably lime, are compounds of bases with oxygen and hydrogen; and these last, like the analogous order among the acids, possess the highest power." Now, surely, perfectly dry and caustic barytes, lime, and strontites, as well as the dry potash and soda obtained by Gay-Lussac and Thenard, are not inferior in alkaline power to the same bodies after they are slacked or combined with water. 100 parts of lime destitute of hydrogen, that is, pure oxide of calcium, neutralize 78 parts of carbonic acid. But 132 parts of Dr. Murray's strongest lime, that is the hydrate, are required to produce the same alka |