By surrounding the capital of a still, or other like apparatus, by a water bath kept at the proper temperature, the alcoholic richness or content of the product may be regulated to the greatest nicety, for any desired strength.
The different statements of chemical authors as to the boiling point, specific gravity, &c., of alcohol, already noticed, may be referred to their having either experimented with samples which have not been absolutely anhydrous, or to their not having made the proper corrections for temperature, and for the different materials of which their vessels and instruments were composed—some probably having been made of glass, and others of brass or some other metal. In some instances the differences are more apparent than real, as in the Tables by Tralles and Lowitz; in the former of which water, at its lowest sp. gr., is taken as the standard. Until recently, the only known source of alcohol was the fermentation of saccharine solutions. Its production by synthesis, though often attempted, is, however, erroneously said to have always failed. It had long been employed as an occasional source of bicarburetted hydrogen (olefiant gas) at a high temperature; but M. Berthelot succeeded in reproducing it, from bicarburetted hydrogen, by agitating the latter, in a closed vessel, with sulphuric acid and metallic mercury (‘Journ. de Chimie Med.,’ 1855, p. 175); and Henry Flennel, nearly thirty years before M. Berthelot’s discovery, found that pure olefiant gas is absorbed by agitation with concentrated sulphuric acid, with the formation of sulphovinic acid, and that by subsequent dilution with water, and distillation, alcohol passes over into the receiver.
ALCOHOLATE. Syn. Alcohate; Alcoholas, L. A salt in which alcohol appears to replace the water of crystallisation, as is the case with certain chlorides, nitrates, &c. Some of them may be formed by simple solution and crystallisation of the salt in alcohol. (Graham.) They are all very unstable, being readily decomposed by water.
ALCOHOLIC. Syn. Alcoholicus, L.; Alcoholique, &c., Fr.; Alkoholisch, Ger. Pertaining to, containing, of the nature of, or made with, alcohol.
ALCOHOLICA. [L.] Syn. Alcoöliques, Fr.; Weingeist-verbindungen, Ger. In pharmacy, liquids containing, or preparations made with, alcohol, as a characteristic ingredient.
ALCOHOLISATION. [Eng., Fr.] Syn. Alcoholisatio, L.; Alcoölisation, &c., Fr.; Alkoholiserung, Ger. In chem. and pharm., the development of the characteristic properties of alcohol in a liquid, or the use of it either as an addition or a menstruum; also the act or process of obtaining alcohol from spirit by rectification.
ALCOHOLOM′ETER (-lŏm′-). Syn. Alcohol′meter (hŏl′-; -hŏm′-‡); Alcoholométrum, L.; Alcoölomètre, Alcoömètre, Alcoholmètre, &c., Fr. An instrument or apparatus used in alcoholometry. Alcoholometers are simply ‘hydrometers’ adapted to the densities of alcohol, either concentrated or dilute. Some of these, as Baumé’s, Carter’s, &c., merely indicate the number of degrees corresponding to the state of concentration of the liquid. Others, of a like construction, as those of Richter (a), Tralles (b), and Gay-Lussac (c), have their stems so graduated as at once to indicate the proportion per cent. of alcohol present, either by weight, or by volume, at some standard temperature. (See engr.) A third class, as those of the Abbé Brossard-Vidal, Field, &c. are essentially thermometers, with scales which indicate the boiling points of spirits of different strengths, instead of the common thermometric degrees; whilst to a fourth class belong the alcoholometer of M. Silbermann, which is based upon the known rate of expansion of alcoholic liquors by heat, expressed in alcoholometric degrees; and that of M. Geissler, which depends on the measurement of the tension of the vapour of the liquid, as indicated by the height to which it raises a small column of mercury. In Syke’s hydrometer, used by officers of the Revenue, the scale of the instrument is enormously extended by the use of movable weights, with each of which it becomes, in fact, a separate instrument, adapted to a certain range of specific gravities.
A very convenient alcoholometer for ordinary purposes (d) has been lately produced by some of the instrument makers. It is of the usual form, but its stem on one side exhibits the per-centage richness of the sample in alcohol by volume; and on the other, the per-centage by weight. Thus, both results may be obtained at one trial. This instrument is sometimes called Richter’s alcoholometer, in England. A further improvement, still more recently introduced, is a similar ‘double-scale’ instrument, showing the degrees of Sykes on one side, and carrying a small spirit-thermometer in the bulb, to which
a scale is fixed ranging from 35° to 82° Fahr.