Vel Ether, in chemistry, (from Aether Vel Ether 219 ardeo, splendeo, bright and splendid,) is called liquor athereus vitriolicus, nitrosus, muriaticus, according to the acid from which it is formed, combined with alcohol. The idea of Macquer, who considered ether as a spirit of wine, dephlegmated, or deprived of water, has little foundation; for the distillation of spirit of wine from the driest alkali docs not resemble ether.

Various are the processes by which AEther is made. The following seems to be the best. Put a certain quantity of alcohol into a receiver, and very gradually add an equal quantity of concentrated sulphuric acid, shaking them together, and waiting till the first addition is incorporated before any more is put in; for, if they are poured together too rapidly, the succeeding heat and ebullition will dissipate a part of the mixture, break the vessel, and endanger the operator. After having mixed the whole in this gradual mode, the retort must be placed on a warm sand-bath, a receiver adapted, and the mixture heated to ebullition, keeping the retort cool with ice or the coldest water. Alcohol first passes over; soon after which, streams of fluid appear in the-neckof the retort and within the receiver, which denote the rising of the aether. Its smell is agreeable: vapours of sulphureous acid succeed the aether; and the receiver must be taken away the moment they appear. If the distillation be continued, sulphureous aether is obtained; and the oil, which is called aethereal oil, or oil of wine, and that which remains in the retort, is a mixture of undecomposed acid, sulphur, and a matter resembling bitumen.

The chemical nature of aether is still little known. Fourcroy and Vauquelin think that in the process the alcohol is decomposed, and its ingredients form a new compound; but aether contains a larger proportion of hydrogen and oxygen, and a less proportion of carbpne. Yet in various experiments with aether charcoal is deposited more copiously than from spirit of wine. Dabit, on the contrary, contends, that aether is only an oxygenated sulphurous acid. He has, however, failed in his proofs. Other chemists have, with greater reason, thought that the acid is decomposed, and that its oxygen unites with the .hydrogen and carbone of the alcohol. Were this the place for chemical discussions, we could shew, that, though the latter opinion is nearer the truth than the former ones, yet that it is far from correct. When the aether is mixed with sulphureous vapours, it must be rectified by a gentle heat; some alkali being first added, to combine with the acid; or, what succeeds better, some black oxide of manganese.

This fluid, besides its appellation of aether, is by some named acidum vitrioli vinosum; by others, spiritus athereus; and in the Pharmacopoeia Edinburgens. it is entitled spt. vini aethereus; and as it may be obtained by means of the different acids, so from the acid employed an appropriate epithet has been added. It should be noted, that aethers produced by the different mineral acids possess different properties. The college of Physicians of London, in order to form the liquor anodynus mineralis Hoffmanni, order spiritus aetheris vitriolicus lb ij. et oleum vini iij. by weight. Chaptal says the composition is spirit of wine and aether, of each two ounces, and twelve drops of the aethereal oil. This is nearly also the composition of Tickel's ether. See Liquor anodynus Hoffmanni

Various modes of preparing this fluid may be seen in the different writers, particularly London and Edinburgh Pharmacopoeias

Some of the properties of this liquid are as follow:

It is the most light, volatile, and inflammable, of all known liquids; with oxygenated fluids, it explodes. Its specific gravity is 0.758.

It swims on the highest rectified spirit of wine, as oil does upon water. In consequence of its volatility, it produces a high degree of cold in evaporating: boils at 98°; and in vacuo, at 20°; and freezes at 46.°. It is one of the most powerful solvents known in chemistry. It will not mix with acids, alkalis, nor vinous spirits; but mixes with ten times its weight of water, by agitation; and is an effectual solvent of oils, balsams, resins, gum resins, wax, etc.

Equal parts of alcohol or aether with sulphuric acid, distilled or passed through ignited tubes of clay, produce what is called a carbonated, oily, hydrogenous gas. This, mixed with oxygenated muriatic gas, forms oil. It is from this property styled by the Dutch chemists, who discovered it, olefant gas. If the tube is of glass, carbone is deposited, and no such gas appears. If two parts of sea-salt, one of manganese, three of alcohol, and one of sulphuric acid, be distilled, a dulcified oxymuriatic acid first comes over, and then an oil called oil of salt.

It extracts gold, wherever it is, from any one or all of the baser metals; and thus gold is better and sooner purified than by any other means.

.AEther is first described in the Dispensatory of Valerius Cordus, published in 1540: the public attention to it was, however, first excited by a publication in the Philosophical Transactions, A. D. 1730, by a German, who calls himself Frobenius. The late Dr. Ward was the first who is known to have used it in England; with tether he instantly relieved the headach, and other pains in the external parts; but for the first publication on its internal use, we are indebted to Mr. Turner, surgeon, in Liverpool, by whom it was prepared for a very extensive sale. He mixed two drams of aether with six or eight ounces of water, and gave from one to four large spoonfuls at a time, repeating the dose as required. Its general effects internally are anodyne and antispasmodic. Others give five or six drops for a dose, first dropping it on sugar; but five times the dose is not too great. In obstinate headachs, vertigos, convulsions, hysteria, rheumatism, flatulent and other disorders of the stomach and bowels, asthmas, hiccough, etc. by its application externally, or administration internally, or both, the most desirable effects have followed. When it is applied externally, procure a bit of linen rag, of such a dimension as to be conveniently covered with the palm of the hand: moisten the rag with the tether, and press it close to the part affected; in two or three minutes the rag will be found dry, and may be taken away: the application must be frequently repeated. Fred. Hoffman, indeed, employed it, in the form of his mineral liquor, as a sedative and antispasmodic.

The aether prepared by Mr. Tickel, of Bath, is recommended chiefly in hydrothorax, but none of the aethers are remarkably diuretic; and, from what we have seen, this medicine apparently acta only as an anodyne and an antispasmodic. In complaints where a remedy of this nature is required, Hoffman is extravagant in the praises of his mineral liquor; and, in later times, Mr. Clutton's febrifuge spirit is little more than an aether acidulated, and disguised by some of the warmer vegetables.

.AEther is either administered on sugar or mixed with water, by means of an almond or mucilage. It is however given with least loss in the former way, or dropped into any fluid in a vial, which must be immediately corked and inverted.

As to the tests of the goodness of tether, Mr. Turner informs us, "that the most perfect sort is obtained by the assistance of the vitriolic acid; that it is colourless, and strikes the nose very strongly with the sulphureous smell; a drop let fall on the hand instantly vanishes, without leaving any moisture behind; five or six drops dropped together upon a table will disappear in a few seconds, and leaves only the appearance of a large oily ring behind."the best tether requires the greatest quantity of water to be mixed with it; if, therefore, to six tea spoonfuls of water, in a small phial, you add one of the tether to be examined, cork it up, and shake them well together; and if, upon standing a little while, some of the tether appears at the top, in the form of oil, sufficient to cover the surface of the mixture, it is good, provided also that it answers the other methods of trial; but if none appears, or not enough to cover the face of the mixture, it was either adulterated or not well rectified: if to this mixture of tether and water you add a little salt of tartar, and any fermentation ensues, the tether was not well rectified. To obtain a powerful medicine, it is necessary that it be free from all adherence of the sulphureous acid, for in proportion to the acid, its virtues are greatly impaired.

See Malouin's Chimie Medicinale, torn. ii. p. 451. Dictionary of Chemistry, edit. ii. Dr. Frobenius's accounts of AEther, inserted in the Philosophical Transactions for 1733 and 1741. Pharm.col. Edinb. Thelond. Med. Obs. and Inq. vol. ii. p. 176 - 186. An Account of the extraordinary Medicinal Fluid called AEther, by M. Turner, surgeon, in Liverpool. Abridgment of the Philosophical Transactions, vol. viii. p. 744. Cyclopediaj edit. A. D. 1788. Beaume's Dissertation on AEther. This last is the most complete work on this subject. Cullen's Mat. Medica. Chaptal, Lavoisier, Fourcroy, Thomson, Annales de Chimie, vols. 21, 23, 24, and 29, 34, 43. Journal de Physique, 45 and 46. Parkinson's Chemical Pocket Book.

-AETherea Herba. See Erysgium.