Lead and its oxide or carbonate, dissolved in the acid which spoils wine, give it a saccharine taste not unpleasant, without any new, or at least perceptible tint, and arrest the progress of the acid fermentation. The wine, however, occasions, according as it is used in a great or small quantity, and according to the constitution of the consumer, a speedy or lingering death, violent colics, obstructions and other maladies; so that one may justly doubt whether, at present, Mars, Venus, or Saturn is most destructive to the human race.
The ancients, in my opinion, knew that lead rendered harsh wine milder, and preserved it from acidity, without being aware that it was poisonous. It was therefore long used with confidence; and when its effects were discovered they were not ascribed to the metal, but to some other cause. When more accurate observation, in modern times, fully established the noxious property of lead, and when it began to be dreaded in wine, unprincipled dealers invented an artful method of employing it, which the law, by the severest punishment, was not able wholly to prevent.
The Greeks and the Romans were accustomed to boil their wine over a slow fire, till only a half, third, or fourth part remained, and to mix it with bad wine in order to improve it. When, by this operation, it had lost part of its watery particles, and had been mixed with honey and spices, it acquired several names, such as mustum, mulsum, sapa, carenum, or caroenum, defrutum[716], &c. Even at present the same method is pursued with sack, Spanish, Hungarian, and Italian wines. In Italy, new wine, which has been thus boiled, is put into flasks, and used for salad and sauces. In Naples it is called musto cotto; but in Florence it still retains the name of sapa. Most of those authors who have described this method of boiling wine expressly say that leaden or tin vessels must be employed; because the wine, by these, is rendered more delicious and durable, as well as clearer. It is, however, certain that must and sour wine by slow boiling, for according to their directions it should not be boiled quickly, must dissolve part of these dangerous metals, otherwise the desired effect could not be produced[717]. Some also were accustomed to add to their wine, before it was boiled, a certain quantity of sea water, which by its saline particles would necessarily accelerate the solution[718].
That the acid of wine has the power of dissolving lead was not unknown to the ancients; for when the Greek and Roman wine-merchants wished to try whether their wine was spoiled, they immersed in it a plate of lead[719]. If the colour of the lead was changed, which undoubtedly would be the case when its surface was corroded, they concluded that their wine was spoiled. It cannot, however, be said that they were altogether ignorant of the dangerous effects of solutions of that metal; for Galen and other physicians often give cautions respecting white lead. Notwithstanding this, men fell upon the invention of conveying water for culinary purposes in leaden pipes[720]; and even at present at London, Amsterdam, Paris, and other places water is conveyed through lead, and collected in leaden cisterns, though that practice has, on several occasions, been attended with alarming consequences[721]. This negligence in modern times makes us not be surprised when we read that the ancients employed leaden vessels. It appears, however, that it was not merely through negligence that this practice prevailed. They were acquainted, and particularly in Pliny’s time, with various processes used in regard to wine[722]; and among these was that of boiling it with lime or gypsum[723]; and the ancient physicians, who had not the assistance of our modern chemistry, thought it more probable that their wine was rendered noxious by the addition of these earths[724], than by the vessels in which it was boiled; and they were the more inclined to this opinion, as they had instances of the fatal effects produced by the use of them[725]. They decried them, therefore, so much, that laws were afterwards made by which they were forbidden to be used, as poisonous and destructive to the human body.
Wine which has once begun to spoil cannot be perfectly restored by lime; for it cannot bring back to it the spirituous part which it has lost, neither can it remove the acid with which it is incorporated; but it can render it imperceptible to the tongue by uniting with it, and forming an earthy salt of an almost insipid taste. This method of improving sour wine is still practised in the island of Zante[726], in Spain[727], on the coast of Africa[728], and in many other countries. It is, however, condemned by several physicians and chemists; because obstructions and other bad effects are to be apprehended from it. Some, on the contrary, consider it as harmless[729]; and I must confess that I should expect no bad consequences from such a small quantity of lime as would be necessary for that purpose. It will produce a salt which will have the same effects as that tartareous crust called wine-stone, and will act as a laxative, like the salts which our apothecaries prepare from that calcareous stone crab’s-eyes, by means of vinegar or lemon-juice. The lime, which the acid of the wine cannot dissolve, will fall to the bottom as a sediment, and assist to clarify the wine. Used however in too great quantity, it may hasten the destruction of the still remaining spirituous part, and render the wine weak; a caution which has been given to wine-merchants by Neumann.
Gypsum is a compound of sulphuric acid with lime, and were it always pure, its effects upon wine would be imperceptible; but as the most kinds of common gypsum contain abundance of carbonate of lime, they effervesce with acids, are dissolved in part by them, and form that salt which I have before said I consider as harmless. By means of this carbonate gypsum improves sour wine, as well as common wine. I took half an ounce of that gypsum which at Osterode is pounded and used as mortar, and which is hard, white, and shining, and almost of the nature of alabaster. When I had pounded it, I put it into strong vinegar in a glass vessel, and suffered it to boil for a few minutes. I then strained it through filtering-paper; and what remained, after it was washed and dried, weighed 215 grains; so that the vinegar had dissolved 25 grains, which were precipitated afterwards by carbonated alkali. I pursued the like process with half an ounce of burnt gypsum, such as is used here for floors; and I found that two ounces of the same vinegar dissolved half a drachm of it, which was somewhat more in proportion than of the former. Every one whom I caused to taste of this vinegar remarked that both had lost a considerable share of their acidity; but that the vinegar which had been boiled with burnt gypsum had lost the most. Few kinds of native gypsum are perfectly pure; and at any rate we have no reason to suppose that the ancients sought pure gypsum for their wines. This method is not yet disused. We are told by Arvieux, that it is still employed in the island of Milo; and I shall here take occasion to observe that salt water also is added to wine there, even at present. Christopher Vega, whom I have before quoted, reproaches the Spaniards with the use of gypsum; and it has been condemned by the modern as well as the ancient physicians. An Englishman of the name of Hardy seems to suspect that gypsum contains lead and arsenical earth[730]; but it appears that this writer doubted whether our gypsum be the same as that of the ancients; and indeed it is necessary, before we use their information respecting natural objects, to examine carefully whether they understood by any name what we understand by it; and what they meant by gypsum has been determined neither by Stephanus, Ferber, nor Gesner. We however know this much, that the ancients burnt their gypsum, and that they formed and cast images of it[731]. In my opinion wine cannot be poisoned by gypsum; and wine-merchants who employ it and lime deserve no severer punishment than brewers, who, in the like manner, render sour beer fitter to be drunk and more saleable.
That the ancients were accustomed to clarify their wine with gypsum, is proved by different passages of the Greek writers on husbandry. They threw gypsum into their new wine; stirred it often round, then let it stand for some time, and, when it had settled, poured off the clear liquor[732]. It would, however, appear that they had remarked that gypsum caused the spirituous part to disappear; for we read that the wine acquired by it a certain sharpness which it afterwards lost, but that the good effects of the gypsum were lasting[733]. This process in modern times has been publicly forbidden, in many countries, as it was in Spain in the year 1348.
Calcined shells were in ancient times used instead of lime[734]. Potters-earth was also thrown into wine, in order to clarify it by carrying the muddy particles with it to the bottom. This method I have seen employed in the breweries at Amsterdam, to purify the water. In the south of France it is used for clarifying wine-stone ley; and in my opinion it might be useful on many other occasions[735].
The ancients poisoned their wine with lead without knowing it; but at what period did that pernicious practice begin of employing sugar of lead and litharge? Litharge was not unknown to the ancients; for it is mentioned by Dioscorides, Aëtius, and others. Sugar of lead is, indeed, more modern; but I have found no information respecting the invention of it, except that it was known to Paracelsus, who died in 1541, and who ventured to prescribe it for some disorders. It was known also to Angelus Sala, one of the most ingenious of the early chemists. In the Roman laws no particular orders occur against the adulteration or poisoning of wine; for what we read in the Institutiones[736] is applicable only to the spoiling of another person’s wine, and thereby occasioning a loss to him; and this explanation is confirmed by the Digesta[737]. The German prohibitions against the adulteration of wine began in the fifteenth century, and were from time to time renewed with additional severity. In that century, we find complaints against this practice with lime, sulphur, and milk; but no instance occurs of the poisoning with lead. I however conjecture that the use of litharge was introduced in the twelfth or thirteenth century; but the framers of the laws were not acquainted with the real poison; and instead of causing it to be examined by the chemists, who it must be confessed had not advanced far in their art, they contented themselves with prohibiting the use of those things which they found considered by the ancients as dangerous.
Among the oldest German prohibitions against the adulteration of wine is that of Nuremberg in the year 1409; in which however there is no notice taken of litharge. Another of the year 1475 is mentioned by Datt[738]; but some Imperial ones of an earlier period may have been lost[739]. In the year 1487 the emperor caused an order against the adulteration of wine to be published by the governments in Swabia, Franconia and Alsace; and this practice was a subject of deliberation at the diet of Rothenburg the same year, and also at the diet of Worms, under Maximilian I., in 1495. At the diet of Lindau the use of sulphur was in particular prohibited, and also at Freyburg in Brisgau in 1498. In the year 1500 the same affair was discussed at Augsburg, and again at that city in 1548, under Charles V. It appears that this business was left afterwards to the care of the different princes, who from time to time issued prohibitions against so destructive a fraud.