It will not be superfluous to subjoin here, what has been already stated respecting the inorganic constituents of wine.

And first, I may observe that every analysis has tended to prove that potash, soda, lime, magnesia, sulphuric, phosphoric, and silicic acid, and chlorine are contained in every wine, and iron in a good many. We have already spoken of alumina (p. 26).

Curiously enough, Fauré, Filhol and others have classed the organic constituents with the inorganic acids.

The largest amount of salts present in 1000 grammes of wine of the Gironde is, according to Fauré:

Sulphate of potass

0 COS

0.09

Phosphate of alumina 0.004 0.04

It is better at once to acknowledge that we can attain no certain results with respect to the grouping of such complex mixtures. Still greater uncertainty prevails as to grouping the constituents of the ash, which are otherwise of no importance, as far as a knowledge of wine is concerned.

The sum of all incombustible ingredients taken collectively, from which the carbonic acid produced

2

during the combustion of tartaric acid must be deducted, is as follows:-In 100 parts of Rhine it varies, according to Diez, between 0·28 and 0·11; that is, from 4th tooth per cent. We get, therefore, as an average 0-28+011019, agreeing exactly with the estimate given of eleven kinds of Rhine wine (p. 291). Champagne gives somewhat less, 0.16 per cent. Bordeaux Sauterne 019, equalling Rhine wine. Roussillon had the largest amount=0.6 per cent. Benicarlo yielded 0.5 per cent. Both wines are rich in tartar, and must therefore leave a good deal of carbonate of potass in the ash.

The influence of the incombustible ingredients of wine has been spoken of already in several places. Most of them have no great effect upon the taste; potash is the most important, as it saturates a part of the tartaric acid, and remains in a state of solution. But tartrate and phosphate of lime, together with the small amount of common and other salts in the wine, have no great influence upon its flavour, colour or smell. As distinctive marks of the genuineness of the wines, they are of the greatest value. Let any one who wishes to convince himself whether a particular wine is adulterated or not, direct his attention to this point, and compare the ash with that of a genuine wine of the same kind as that under examination.

CHAPTER XXIV.

ODORIFEROUS CONSTITUENTS OF WINE.

A FEW years ago it seemed as if the cause of the multiplicity of agreeable odours diffused by wine would long remain enveloped in obscurity; but happily light has been shed upon this subject, and although we are still far from being able to say with certainty this or that kind of wine owes its peculiar character to such a substance, we have at least a satisfactory acquaintance with much that we wish to know. The attempt has often been made to separate the actual peculiar odoriferous ingredient out of aromatic wine. Since, however, we know that of the most important by weight of these odoriferous ingredients 10000th only appears in wine, this plan may be given up, although Fauré tried to carry it out eight years ago, by distilling 500 grammes of wine, and out of 4 or 5 grammes of the first destillate kept as cool as possible, endeavouring to separate the odoriferous constituents. Even were a minimum of the ingredients which diffuse aroma to be thus obtained, this is not the most suitable manner for discriminating their nature.

The so-called fusel oils are those which have shed most light upon this subject, they being ethereal oils,

a mixture of several liquids in which the solid substances called fatty acids are dissolved: this mixture may be obtained either by distilling large quantities of wine (as in brandy distilleries), or by subjecting the grape-skins, which have already fermented with the juice, to distillation. In this manner substances actually existing in, and belonging to the wine, were obtained in such abundance as to allow of the mixed bodies being separated, and their individual constituents separately analysed. The result has shown that many of these ingredients may be artificially imitated; and those who adulterate wine have therefore attempted to improve the less aromatic wines by the addition of some odoriferous substance.

In treating shortly of these important bodies, I shall distinguish; 1st, those substances which are proper to all wines; 2nd, those which are developed in wine after a length of time; 3rd, such as depend entirely on the peculiarities of the places in which the grapes were grown.

I may here observe that this chapter differs in arrangement from the former part of this treatise.

I have taken into consideration substances whose existence, though not exactly proved, may yet be presumed in this or that kind of wine. For without giving a general view of the relations of these substances, I could hardly have spoken of the great variety and abundance of odoriferous ingredients which either have been or may be found in wine.

SUBSTANCES GENERALLY FOUND TO POSSESS A

VINOUS SMELL.

It may appear singular, but is nevertheless true, that the ethereal ingredient which imparts to the grapejuice, after fermentation, the vinous odour (alcohol excepted) is itself fœtid. No one can find it agreeable; it exactly resembles the liquid which imparts its peculiar odour to moutwyn.*

After the œnanthic ether of wine had been examined by Liebig and Pélouze, I separated the same liquid from the fluid from which moutwyn is distilled,† and Pélouze has since permitted me to compare the liquids; and in combination, as in other qualities, when obtained by simple distillation, they resemble each other; in both cases the smell is disagreeable.

The substance is prepared not from the first portion of the destillate, but from that which comes over last, and in the case of moutwyn, from the residue after weak spirit has been distilled from the liquid. This remark is of some importance, inasmuch as it shows that œnanthic ether is not very volatile, which again renders it clear that the bouquet of aromatic wine cannot be ascribed to oenanthic ether. This

* Moutwyn, literally "malt wine," is obtained by distilling the second destillate, and is also called in Holland "corn wine." We retain the designation "moutwyn."-Translator's note.

+ Nat. en Scheik. Archief. deel. 5, p. 103.