the precipitate thus induced will possess a bottle-green colour, more or less dark, according to the natural hue of the wine; if colour has been artificially obtained, the results will be as follows: Tournesol will give a precipitate of a bright violet colour, Brazil-wood will occasion a brownishred precipitate, elderberries or privet a brownish-violet precipitate, whortleberries a precipitate of the colour of dirty wine lees, with logwood the precipitate will be coloured lake-red. Vogel recommends, for the same purpose, the use of acetate of lead; in genuine wines, it produces a greenish-gray precipitate, which is not the case with coloured wines. Prout gives ammonia, as a test for the determination of artificial colours in wines; this reagent occasions in genuine wines an olive-green colour, and a precipitate containing phosphate of ammonia and magnesia or triple phosphate; in those artificially coloured, the precipitate forms more gradually, in less quantity, and is free from admixture with triple phosphate.1

Alcohol. This fluid is added in large proportion more especially to Port and Sherry, but also to most of the wines sold in the London market, for the purpose of making them stronger to the taste, and preventing their decomposition. The wine reserved for exportation at Oporto is mixed with a considerable quantity of brandy, and when it arrives in this country possesses a dark, purple, or inky colour, with an astringent, bitter-sweet taste, and a strong flavour and odour of brandy; and it is only after being kept for ten or fifteen years in bottle, that the odour of the brandy is completely subdued, and the genuine aroma of the wine developed. During the process of melioration, a considerable portion of the extractive and colouring matter

1 Henderson's History of Wines.'

is deposited on the sides of the bottles, in the form of crust, and when this takes place to a great extent, the wine has been found to have lost its flavour and aroma. In those wines which have been manufactured from white grapes, and coloured with elderberries or other foreign materials, this change occurs much earlier than in others; these colouring matters are often added by wine-makers, together with a large quantity of brandy, when there is a deficiency of black grapes. It was stated before the Committee of the Wine Duties, in 1852, by Mr. Forrester, an extensive vine-grower of Portugal, that no Port is brought to England with less brandy in it than three gallons to a pipe of one hundred and fifteen gallons, and that if it contained less, the English would not purchase it. (To determine the amount of alcohol in wines, see p. 126.)

Artificial wines. Not much is known on the methods employed in this country for making artificial wines. There are many recipes for preparing Port wine; thus Mr. Redding stated, in his evidence before the Wine Duties Committee, that the following is a mode of making surreptitious Port in London:

26

common Port,
Mountain,

brandy-casks washings, colouring liquid, &c.

Another recipe recorded is-12 gallons of strong Port, 6 of rectified spirits, 3 of brandy, and 42 of rough cider, making 63 gallons of imitative Port.1 There is little doubt, but that French and other foreign wines are also imitated, and artificially made in this country.

1The Food of London,' by Dodd.

Adulterations of beer.-This healthy and agreeable beverage used to be prepared about twenty-five years ago from a mixture containing many violent poisons, as Indian hemp (Cocculus Indicus), opium, sulphuric acid, sulphate of iron, &c.; the addition of strychnine even to beer has more recently been suspected.

At the present time, the principal adulterations of beer (more especially porter), consist of water, to increase the bulk of the fluid, and burnt sugar and salt, to restore in a measure its colour and flavour.

Water. From the circumstance that the amount of alcohol in beer is not subject to considerable variations, it is evident that, when water is added to beer, the proportion of alcohol it contains will be diminished. In order, therefore, to detect the adulteration in question, determine the quantity of spirit existing in the fluid (p. 126). The samples of stout examined by the Commission of the 'Lancet,' yielded from 7.15 to 4.53 per cent. of alcohol, sp. gr. 0·796, obtained from brewers, or purchased at their taps, and from 4-87 to 3.25 per cent. of alcohol when procured from publicans. Analogous results were derived from the examination of various samples of porter; the amount of alcohol in porter obtained from the tap varying from 4.51 to 2:42 per cent., whilst in that purchased from publicans it ranged from 3.97 to 1.81 per cent. A more accurate method of determining the amount of water in alcoholic liquors, is to estimate the proportion of alcohol in a sample of the fluid, and evaporate another weighed quantity to dryness; the weight of the residue, subtracted from that of the fluid, shows how much water and alcohol it contained; and this last result, minus the quantity of alcohol previously determined, is equal to the amount of water present.

Sugar. The use of this substance is allowed in breweries; still, its admixture with beer is probably not frequent, since sugar is considered to prevent it from keeping well. Moreover, the high price of sugar forms an obstacle to its use in breweries.

Burnt sugar or treacle was extensively employed some years ago, with the view of increasing the dark colour of porter and stout; the ingredient known as Essentia bina, formerly used in the manufacture of beer, consisted of moist sugar boiled in an iron vessel until it had become syrupy, perfectly black, and extremely bitter. (For the detection. and quantitative determination of sugar in alcoholic beverages, see pp. 120 and 121.)

Salt. According to Dr. Hassall, it appears that salt is almost constantly present in porter, the addition being made first by the brewers themselves, and subsequently by the publicans, in order to assist in restoring the flavour of beer which has been reduced in strength from the addition of water. Salt is used by the brewers in the following manner: "It is first mixed up in a tub with some kind of flour, usually wheat flour, and the mixture is cast by handfuls over the surface of the wort in the cooling vat." 1 To estimate the quantity of salt, or chloride of sodium, contained in an alcoholic beverage, evaporate a sample of the fluid to dryness, or dry the residue left in the retort after the determination of the alcohol; burn the solid substance, and dissolve the ashes in distilled water; finally, add nitrate of silver to the solution, and proceed as directed at p. 25.

Acid in beer.-The acidity in beer is very considerable; it depends, probably, on the presence of malic and lactic acids. In many cases, however, acetic acid or vinegar is formed in beer from a decomposition or excessive fermen

1 Dr. Hassall on Food, &c., p. 631.

tation of its sugar; the beverage is then very sour, and unfit for use. (For the detection and estimation of the acidity of beer, see p. 129.) There is some reason to believe that sulphuric acid is occasionally used to give astringency to beer, in which case the addition of chloride of barium to the liquor will cause the formation of a bulky precipitate insoluble in nitric acid.

Sulphate of iron.-This substance was employed formerly in the manufacture of beer, and is possibly used for the purpose in question at the present time. Should this substance be present in an alcoholic beverage, by adding ammonia and sulphide of ammonium to the fluid, a black precipitate will be produced.1 For sulphuric acid, test as directed in the preceding paragraph.

Adulterations of spirits.-Spirits may be adulterated with water, sugar, capsicum, cinnamon or cassia, various sulphates and free sulphuric acid, and lead.

Water and sugar.-For the methods employed to detect the presence of an excess of water, and to estimate the amount of alcohol and sugar in alcoholic liquors, I beg to refer the reader to pp. 133, 126, and 121.

Capsicum or cayenne pepper.-A ready means is offered for discovering the presence of this spice in spirits, from the taste of the residue obtained by evaporating the fluid nearly to dryness. If it should contain cayenne pepper, the taste of the residue will be hot and fiery.

Cinnamon or cassia.-The oils of these substances are sometimes used for flavouring gin. In order to detect them, the spirit should be concentrated at a low temperature, and finally tested as in the case of capsicum.

Compounds containing sulphuric acid. The presence of 1 Examine also the ashes of beer for iron, see p. 52.