CHAPTER X.

NATURE AND COMBINATIONS OF ALCOHOL.

Under the names of rum, brandy, gin, whiskey, usquebaugh; wine, cider, beer, and porter Alcohol, is become the bane of the Christian world.-Dar win's Zoonomia.

Throughout the wide-spread kingdom of animal and vegetable nature, not a particle of alcohol, in any form or combination whatever, has been found, as the effect of a single living process; but it arises out of the decay, the dissolution, and the wreck of organized matter.-Dr. Mussey's Temp. Prize Essay.

ALCOHOL, received its name from an Arabian physician, by whom it was first discovered. The phrase is said to be derived from the Arabic words Al the, and Kahol, a fine impalpable powder. With this substance, the ladies of Barbary were accustomed to tinge the hair and edges of their eyelids. Dr. Shaw remarks, that none of the women of Barbary think themselves completely dressed, until they have tinged their hair as well as the edges of their eyelids, with al-ka-hol, the powder of lead ore. *In course of time, however, this word appears to have been used to express the separation of any subtle or powerful substance, from the grosser materials with which it was connected. Hence, perhaps, its application to the refined and potent stimulus extracted from fermented liquors.

The name of alcohol in the present day, is exclusively applied to the spirit or intoxicating liquor, contained in all fermented drinks. Alcohol was formerly supposed to be the generical product of distillation. It is now acknowledged, that distillation separates it only from fermented liquors where it had been previously formed.

Alcohol in its pure state, is light and colourless, and of the specific gravity, 0·796 at 60 degrees Fahrenheit. It has a powerful odour when submitted to the smell, and is highly pungent and irritating to the taste. Alcohol is exceedingly inflammable, and instantaneously burns when in

• Travels through Barbary, p. 294.

contact with ignited matter. The flame has a peculiar bluish appearance in the dark; the intenseness of which depends on the purity of the spirit which is ignited. On dead animal matter, this powerful fluid acts as an astringent and antiseptic, lessening the bulk of the substance to which it is applied, and preserving it from speedy decomposition.

Alcohol is composed of three gases, carbon, hydrogen, and oxygen. The following are the proportions of one hundred parts of pure alcohol, according to the calculations of Saussure, the eminent French chemist.

The alcohol used in medicinal preparations, by direction of the London Pharmacopoeia, is of specific gravity, 815 and contains 93 parts of pure or anhydrous alcohol, and 7 parts of water. The rectified spirit of the chemist, sp. gr. 835, contains 15 per cent. of water.

COMBINATIONS OF ALCOHOL.

The nature and results of fermentation, form an interesting and important subject for philosophical investigation.

1. The nature of fermentation.-Fermentation is now known to be one of the first results of the partial decomposition of vegetable matter. The several stages of fermentation through which decomposition passes previous to its completion, are denominated the vinous, the acetous, and the putrefactive. Each of which, is subject to certain laws, which would go on to completion, were it not for the obstructing hand of man. Alcohol is the product of the first stage of decomposition, which is from thence termed the vinous. Vinous compounds, when subjected to a certain temperature, or exposed to the atmosphere, and unmixed with artificial and counteracting compounds, gradually run into the acetous or second stage of decay, a condition which is subsequently followed by putrefac

tion.

In course of time, man, by the exercise of his ingenuity,

Annal. de Chimie.

found that he could arrest the progress of vegetable decomposition, at those periods which most suited his purposes. By this means he had placed at his disposal, vinegar, which is applied to many useful purposes, and fermented liquors, by which he might indulge and gratify unnatural and injurious passions.

The present inquiry, however, only relates to the vinous or first stage of decomposition, which, like every other operation of nature, is subject to necessary and invariable laws.

2. Conditions necessary to fermentation. The presence of a sufficient quantity of water.-To produce fermentation, the materials must be in a liquid state. A mixture of sugar and water will not properly ferment in a state of syrup, but when reduced to a liquid condition, it becomes susceptible of fermentation. It has already been seen, that the ancients were acquainted with this fact, and that by inspissating, or boiling down the juice of fruits, they prevented it from running into a state of fermentation.*

[It appears from Pliny, that the juice which flowed from the gentle pressure of the grapes upon each other, when heaped in the baskets or troughs before being trodden, was placed in vessels carefully secured, and set aside till the ensuing summer, when it was exposed still unfermented, for forty days to a strong sun. This juice was very saccharine. When the saccharine matter was small, thus rendering its preservation doubtful, the must was placed in an amphora, coated and secured by being well pitched and corked, and then sunk in a pond, where it lay till winter, when it was taken up and found to have lost all tendency to fermentation, and might be preserved a year or more. Sometimes it was sunk in the sea, when it was thought to acquire very speedily the flavor of age. This was something between a syrup and a wine. Other modes of preventing fermentation were adopted by the ancients, which we shall point out hereafter.-AM. ED.]

A proper temperature. The regulation of the temperature forms an important item in the preparation of intoxi

"Must, or the juice of the grape, ferments spontaneously; but Gay Lussac has observed, that these juices cannot begin to ferment unless they are exposed to the air. By heating must to 212 degrees, and then corking it carefully, the juice may be preserved without change; but if it be exposed to the air for a few seconds only, it absorbs oxygen, and fermentation takes place. From this it would appear, that the must contains a principle which is convertible into yest, or at least acquires the characteristic property of that substance, by absorbing oxygen."-Turner's Elements of Chemistry, p. 119.

cating liquors. In hot countries, the atmospheric heat is in general sufficient to carry on the process of fermenta. tion. Vinous fermentation will not take place at a temperature of thirty-two degrees, The fermentation is languid at fifty degrees, but rapid at sixty degrees. The latter temperature, therefore, is required to produce the necessary fermentation for the production of alcohol. Great care is required to prevent the acetous fermentation which commences at seventy degrees.

The presence of a ferment in addition to fermentable matter.-The grape contains all the requisites for fermentation, namely," water, ferment"* and fermentable water. Fermentation, however, cannot take place until the fruit is dispossessed of its vitality. The whole of its substance indeed must be blended. This circumstance is accounted for by the fact, that the ferment and fermentable matter are placed in different divisions of fruit. The wine-press, however, amalgamates the whole. Yest is employed as a ferment in the preparation of malt liquors. Vegetables, which contain a large amount of saccharine matters, are most capable of fermentation. In the grape, and in similar fruits, the elements are already formed. In malt liquors, however, saccharine matter is developed from the grain in sufficient quantity by the process of malting.†

3. Changes effected by fermentation.-These changes principally depend on a separation of the gaseous elements of the saccharine matter, and the recomposition of a portion of these elements in the form of a new compound. Every forty-five parts of sugar, will give one equivalent of alcohol and one of carbonic acid.

The following table will explain the changes which take place during vinous fermentation:

This "ferment" has been found to be analagous to the gluten of plants, and if gluten is substituted for it, fermentation succeeds equally well. The saccharine part of must resides in the cells of the grapes; but the fermenting is lodged on the membranes that separate the cells. Hence, in the grape they are not in contact, and fermentation cannot take place.-AM. ED.

In addition to the conditions mentioned by our author, we may add, that all juices of fruits which undergo the vinous fermentation, contain an acidThus the apple contains malic acid; the lemon, citric acid; the grape, tartaric and malic acids. It has been lately ascertained that must will not ferment if the tartaric acid be wholly separated from it. The strength of wine may be materially increased by adding tartar and sugar to the must. The more sugar there is in grapes the less tartar they contain; hence, if to very saccharine must, tartar and gluten be added, a much larger amount of alcohol is developed. Sweet wines grow gradually stronger by the slow fer inentation going on, by which the sugar is decomposed.-AM. ED.

The whole of the hydrogen, two parts of carbon, and one of oxygen, unite and form alcohol. One part of carbon and two of oxygen, combine and form carbonic acid, which is evolved in a gaseous form.

In order to obtain alcohol in an absolute condition, it is necessary to subject it to some mechanical agency-as distillation. By this process it is separated from foreign matters of various kinds, such as water, colouring matter, and vegetable extractive.

COMBINATIONS OF WINE. Wines vary much in their strength, taste, and colour. These conditions depend on climate, soil, and other circumstances of like nature. Winemaking depends greatly on artificial aid, and is not altogether the natural process which it is generally supposed to be. Wine prepared in a natural manner, without the adventitious aid of the winemaker's experience would not be relished by modern society. Imperfect fermentation indeed would be the result. Some wines would contain too small a quantity of saccharine matter, others too much of the tartar or acid principle. In some grapes moreover, there is a deficiency of sugar. deficiency of sugar. This is frequently remedied by boiling the juice, and evaporating the superfluous water; and at other times, either by the addition of a sufficient quantity of extraneous sugar, or by cutting the stem while growing upon the tree, so as to deprive the grapes of their usual supply of watery particles. "Donovan," affirms, "that it is indispensably necessary to enrich the juice of some grapes, by methods like these: otherwise they will rapidly run into a hasty feeble fermentation, which would again pass quickly into the acetous stage." "The result," he further remarks, "would be a poor, spiritless, acidulous wine."* Thus also in regard to the temperature, and other conditions of the utmost importance in the manufacture of wine. The winemaker is ever on the alert interrupting the operations of nature, and rendering such assistance as will supply wine in accordance with the acquired appetites of mankind.

In order to improve their flavour and strength, all wines

• Domestic Economy, vol. i.