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VERDIGRIS, or SPANISH GREEN

Respecting the preparation of verdigris, various and in part contradictory opinions have been entertained; and at present, when it is with certainty known, it appears that the process is almost the same as that employed in the time of Theophrastus, Dioscorides, and Vitruvius⁴⁶². At that period, however, every natural green copper salt was comprehended under the name of ærugo. Dioscorides and Pliny say expressly, that a substance of the nature of those stones which yielded copper when melted, was scraped off in the mines of Cyprus; as is still practised in Hungary, where the outer coat of the copper ore is collected in the like manner, and afterwards purified by being washed in water. Another species, according to the account of Dioscorides, was procured from the water of a grotto in the same island; and the most saleable natural verdigris is still collected by a similar method in Hungary. The clear water which runs from old copper-works is put into large vessels, and after some time the green earth falls to the bottom as a sediment.

The artificial ærugo of the ancients, however, was our verdigris, or copper converted into a green salt by acetic acid. To discover the method of procuring this substance could not be difficult, as that metal contracts a green rust oftener than is wished, when in the least exposed to acids. The ancients, for this purpose, used either vessels and plates of copper, or only shavings and filings; and the acid they employed was either the sourest vinegar, or the sour remains left when they made wine; such as grapes become sour, or the stalks and skins after the juice had been pressed from them⁴⁶³. Sometimes the copper was only exposed to the vapour of vinegar in close vessels, so that it did not come into immediate contact with the acid; in the same manner as was practised with plates of lead in the time of Theophrastus, when white-lead was made, and as is still practised at present. Sometimes the metal was entirely covered with vinegar, or frequently besprinkled with it, and the green rust was from time to time scraped off; and sometimes copper filings were pounded with vinegar in a copper mortar, till they were changed into the wished-for green salt. This article was frequently adulterated, sometimes with stones, particularly pumice-stone reduced to powder, and sometimes with copperas. The first deception was easily discovered; and to detect the second, nothing was necessary but to roast the verdigris, which betrayed the iron by becoming red; or to add to the verdigris some gall-nut, the astringent ingredients of which united with the oxide of iron of the copperas, and formed a black ink.

In early periods verdigris was used principally for making plasters, and for other medicinal purposes; but it was employed also as a colour, and on that account it is by Vitruvius reckoned among the pigments. When applied to the former purpose, it appears that the copper salt was mixed with various other salts and ingredients. One mixture of this kind was called vermicular verdigris⁴⁶⁴, the accounts of which in ancient authors seem to some commentators to be obscure; but in my opinion we are to understand by them, that the ingredients were pounded together till the paste they formed assumed the appearance of pieces or threads like worms; and that from this resemblance they obtained their name. For the same reason the Italians give the name of vermicelli to wire-drawn paste of flour used in cookery⁴⁶⁵. When the process for making this kind of verdigris did not succeed, the workmen frequently added gum to it, by which the paste was rendered more viscous; but this mixture is censured both by Pliny and Dioscorides. It appears that the greater part of the verdigris in ancient times was made in Cyprus, which was celebrated for its copper-works, and in the island of Rhodes.

At present considerable quantities of verdigris are manufactured at Montpelier in France, and by processes more advantageous than those known to the ancients⁴⁶⁶. The dried stalks of grapes are steeped in strong wine, and with it brought to a sour fermentation. When the fermentation has ceased, they are put into an earthen pot, in alternate layers with plates of copper, the surface of which in a few days is corroded by the acetic acid, and the salt is then scraped off. It is certain, that, even in the fifteenth century, the making of verdigris was an old and profitable branch of commerce in France. The city of Montpelier having been obliged to expend large sums in erecting more extensive buildings to carry it on, and having had very small profits for some years before, received by letters patent from Charles VI., in 1411, permission to demand sixteen sous for every hundred weight of verdigris made there. In later times this trade has decayed very much. Between the years 1748 and 1755, from nine to ten thousand quintals were manufactured annually, by which the proprietors had a clear profit of 50,000 crowns; but a sudden change seems to have taken place, for in 1759 the quantity manufactured was estimated at only three thousand quintals. This quantity required 630 quintals of copper, valued at 78,750 livres: the expenses of labour amounted to 1323 livres; the necessary quantity of wine, 1033 measures, to 46,485 livres, and extraordinaries to 10,330 livres; so that the three thousand quintals cost the manufacturers about 136,888 livres. In the year 1759, the pound of verdigris sold for nine sous six deniers: so that the three thousand quintals produced 142,500 livres, which gave a net profit of only 5612 livres. Other nations, who till that period had purchased at least three-fourths of the French verdigris, made a variety of experiments in order to discover a method of corroding copper which might be cheaper; and some have so far succeeded that they can supply themselves without the French paint in cases of necessity⁴⁶⁷.

In commerce there is a kind of this substance known under the name of distilled verdigris, which is nothing else than verdigris purified, and crystallized by being again dissolved in vinegar⁴⁶⁸. For a considerable period this article was manufactured solely by the Dutch, and affords an additional example of the industry of that people. Formerly there was only one person at Grenoble acquainted with this art, which he kept secret and practised alone; but for some years past manufactories of the same kind have been established in various parts of Europe.

The German name of verdigris (Spangrün) has by most authors been translated Spanish green; and it has thence been concluded that we received that paint first from the Spaniards. This word and the explanation of it are both old; for we find ærugo, and viride Hispanicum, translated Spangrün, Spongrün, or Spansgrün, in many of the earliest dictionaries⁴⁶⁹, such as that printed in 1480⁴⁷⁰. For this meaning, however, I know no other proof than the above etymology, which carries with it very little probability; and I do not remember that I ever read in any other works that verdigris first came from the Spaniards.

SAFFRON

That the Latin word crocus signified the same plant which we at present call saffron, and which, in botany, still retains the ancient name, has, as far as I know, never been doubted; and indeed I know no reason why it should, however mistrustful I may be when natural objects are given out for those which formerly had the like names. The moderns often apply ancient names to things very different from those which were known under them by the Greeks and the Romans: but what we read in ancient authors concerning crocus agrees in every respect with our saffron, and can scarcely be applied to any other vegetable production. Crocus was a bulbous plant, which grew wild in the mountains. There were two species of it, one of which flowered in spring, and the other in autumn. The flowers of the latter, which appeared earlier than the green leaves that remained through the winter, contained those small threads or filaments⁴⁷¹ which were used as a medicine and a paint, and employed also for seasoning various kinds of food⁴⁷².

It appears that the medicinal use, as well as the name of this plant, has always continued among the Orientals; and the Europeans, who adopted the medicine of the Greeks, sent to the Levant for saffron⁴⁷³, until they learned the art of rearing it themselves; and employed it very much until they were made acquainted with the use of more beneficial articles, which they substituted in its stead. Those who are desirous of knowing the older opinions on the pharmaceutical preparation of saffron, and the diseases in the curing of which it was employed, may read Hertodt’s Crocologia, where the author has collected all the receipts, and even the simplest, for preparing it⁴⁷⁴.

What in the ancient use of saffron is most discordant with our taste at present, is the employing it as a perfume. Not only were halls, theatres, and courts, through which one wished to diffuse an agreeable smell, strewed with this plant⁴⁷⁵, but it entered into the composition of many spirituous extracts, which retained the same scent; and these costly smelling waters were often made to flow in small streams, which spread abroad their much-admired odour⁴⁷⁶. Luxurious people even moistened or filled with them all those things with which they were desirous of surprising their guests in an agreeable manner⁴⁷⁷, or with which they ornamented their apartments. From saffron, with the addition of wax and other ingredients, the Greeks as well as the Romans prepared also scented salves, which they used in the same manner as our ancestors their balsams⁴⁷⁸.

Notwithstanding the fondness which the ancients showed for the smell of saffron, it does not appear that in modern times it was ever much esteemed. As a perfume, it would undoubtedly be as little relished at present as the greater part of the dishes of Apicius, fricassees of sucking puppies⁴⁷⁹, sausages, and other parts of swine, which one could not even mention with decency in genteel company⁴⁸⁰; though it certainly has the same scent which it had in the time of Ovid, and although our organs of smelling are in nothing different from those of the Greeks and the Romans. From parts of the world to them unknown, we have, however, obtained perfumes which far excel any with which they were acquainted. We have new flowers, or, at least, more perfect kinds of flowers long known, which, improved either by art or by accident, are superior in smell to all those in the gardens of the Hesperides, of Adonis and Alcinous, so much celebrated. We have learned the art of mixing perfumes with oils and salts, in such a manner as to render them more volatile, stronger, and more pleasant; and we know how to obtain essences such as the ancient voluptuaries never smelt, and for which they would undoubtedly have given up their saffron. The smelling-bottles and perfumes which are often presented to our beauties, certainly far excel that promised by Catullus to a friend, with the assurance that his mistress had received it from Venus and her Cupids, and that when he smelt it he would wish to become all nose:

 
Nam unguentum dabo quod meæ puellæ
Donarunt Veneres Cupidinesque,
Quod tu quom olfacies, deos rogabis,
Totum ut te faciant, Fabulle, nasum.
 

It cannot, however, be denied that both taste and smell depend very much on imagination. We know that many articles of food, as well as spices, are more valued on account of their scarcity and costliness than they would otherwise be. Hence things of less value, which approach near to them in quality, are sought after by those who cannot afford to purchase them; and thus a particular taste or smell becomes fashionable. Brandy and tobacco were at first recommended as medicines; they were therefore much used, and by continual habit people at length found a pleasure in these potent and almost nauseating articles of luxury. Substances which gratify the smell become, nevertheless, like the colour of clothes, oft unfashionable when they grow too common. Certain spiceries, in which our ancestors delighted, are insupportable to their descendants, whose nerves are weak, and more delicate; and yet many of the present generation have accustomed themselves to strong smells of various kinds, by gradually using them more and more, till they have at length become indispensable wants. Some have taken snuff rendered so sharp by powdered glass, salts, antimony, sugar of lead, and other poisonous drugs, that the olfactory nerves have been rendered callous, and entirely destroyed by it.

That saffron was as much employed in seasoning dishes as for a perfume, appears from the oldest work on cookery which has been handed down to us, and which is ascribed to Apicius. Its use in this respect has been long continued, and in many countries is still more prevalent than physicians wish it to be. Henry Stephen says, “Saffron must be put into all Lent soups, sauces, and dishes: without saffron we cannot have well-cooked peas⁴⁸¹.”

It may readily be supposed that the great use made of this plant in cookery must have induced people to attempt to cultivate it in Europe; and, in my opinion, it was first introduced into Spain by the Arabs, as may be conjectured from its name, which is Arabic, or rather Persian⁴⁸². From Spain it was, according to every appearance, carried afterwards to France, perhaps to Albigeois, and thence dispersed into various other parts⁴⁸³. Some travellers also may, perhaps, have brought bulbs of this plant from the Levant. We are at least assured that a pilgrim brought from the Levant to England, under the reign of Edward III., the first root of saffron, which he had found means to conceal in his staff, made hollow for that purpose⁴⁸⁴. At what period this plant began to be cultivated in Germany I do not know; but that this was first done in Austria, in 1579, is certainly false. Some say that Stephen von Hausen, a native of Nuremberg, who about that time accompanied the imperial ambassador to Constantinople, brought the first bulbs to Vienna, from the neighbourhood of Belgrade. This opinion is founded on the account of Clusius, who, however, does not speak of the autumnal saffron used as a spice, but of an early sort, esteemed on account of the beauty of its flowers⁴⁸⁵. Clusius has collected more species of this plant than any of his predecessors; and has given an account by whom each of them was first made known.

In the fifteenth and following century, the cultivation of saffron was so important an article in the European husbandry, that it was omitted by no writer on that subject; and an account of it is to be found in Crescentio, Serres, Heresbach, Von Hohberg, Florinus, and others. In those periods, when it was an important object of trade, it was adulterated with various and in part noxious substances; and attempts were made in several countries to prevent this imposition by severe penalties. In the year 1550, Henry II., king of France, issued an order for the express purpose of preventing such frauds, the following extract from which will show some of the methods employed to impose on the public in the sale of this article⁴⁸⁶: “For some time past,” says the order, “a certain quantity of the said saffron has been found altered, disguised and sophisticated, by being mixed with oil, honey, and other mixtures, in order that the said saffron, which is sold by weight, may be rendered heavier; and some add to it other herbs, similar in colour and substance to beef over-boiled, and reduced to threads, which saffron, thus mixed and adulterated, cannot be long kept, and is highly prejudicial to the human body; which, besides the said injury, may prevent the above-said foreign merchants from purchasing it, to the great diminution of our revenues, and to the great detriment of foreign nations, against which we ought to provide,” &c.

[The high price demanded for saffron offers considerable temptation to adulteration, and this is not uncommonly taken advantage of. The stigmata of other plants, besides the true saffron crocus (Crocus sativus), are frequently mixed with those which are genuine; moreover, many other foreign substances are added, such as the florets of the safflower (Carthamus tinctorius), those of the marigold (Calendula officinalis), slices of the flower of the pomegranate, saffron from which the colouring has been previously extracted, and even fibres of smoked beef. Most of these adulterations may be detected by the action of boiling water, which softens and expands the fibres, thus exposing their true shape and nature. The cake saffron of commerce appears entirely composed of foreign substances. Great medicinal virtues were formerly attributed to saffron. Its principal use is now as a colouring matter.]

ALUM

This substance affords a striking instance how readily one may be deceived in giving names without proper examination. Our alum was certainly not known to the Greeks or the Romans; and what the latter called alumen⁴⁸⁷ was vitriol, (the green sulphate of iron)⁴⁸⁸; not however pure, but such as forms in mines. To those who know how deficient the ancients were in the knowledge of salts, and of mineralogy in general, this assertion will without further proof appear highly probable⁴⁸⁹. Alum and green vitriol are saline substances which have some resemblance; both contain the same acid called the vitriolic or sulphuric; both have a strong astringent property, and on this account are often comprehended under the common name of styptic salts; and both are also not only found in the same places, but are frequently obtained from the same minerals. The difference, that the vitriols are combinations of sulphuric acid with a metallic oxide, either that of iron, copper or zinc, and alum on the other hand with a peculiar white earth, called on this account alumina, has been established only in modern times⁴⁹⁰.

A stronger proof however in favour of my assertion, is what follows: – The Greeks and the Romans speak of no other than natural alum; but our alum is seldom produced spontaneously in the earth, and several of our most accurate mineralogists, such as Scopoli and Sage, deny the existence of native alum⁴⁹¹. Crystals of real alum are formed very rarely on minerals which abound in a great degree with aluminous particles, when they have been exposed a sufficient time to the open air and the rain; and even then they are so small and so much scattered, that it requires an experienced and attentive observer to know and discover them. The smallest trace of alum-works is not to be found in the ancients, nor even of works for making vitriol (sulphate of iron), except what is mentioned by Pliny, who tells us that blue vitriol was made in Spain by the process of boiling; and this circumstance he considers as the only one of its kind, and so singular, that he is of opinion no other salt could be obtained in the same manner⁴⁹². Besides, everything related by the ancients of their alum agrees perfectly with native vitriols: but to describe them all might be difficult; for they do not speak of pure salts, but of saline mixtures, which nature of itself exhibits in various ways, and under a variety of forms; and every small difference in the colour, the exterior or interior conformation, however accidental, provided it could be clearly distinguished, was to them sufficient to make a distinct species, and to induce them to give it a new name⁴⁹³.

The celebrity which the ancient alum had, as a substance extremely useful in dyeing and medicine, was entirely forgotten when the alum of the moderns became known; but this celebrity was again revived when it was discovered that real alum could be often made from minerals containing sulphur compounds; or that where the latter are found there are generally minerals which abound with it. In many of these places alum-works have in the course of time been erected; and this circumstance has served in some measure to strengthen the opinion that the alum of the ancients and that of the moderns are the same salt; because where the former was found in ancient times, the latter has since been procured by a chemical process. Some historians of the fifteenth century even speak of the alum-works erected at that period, as if the art of making this salt had only been revived in Europe.

The ancients procured their alum from various parts of the world. Herodotus mentions Egyptian alum; for he tells us that when the people of Delphos, after losing their temple by a fire, were collecting a contribution in order to rebuild it, Amasis king of Egypt sent them a thousand talents of alum⁴⁹⁴. In Pliny’s time the Egyptian alum was accounted the best. It is well known that real alum is reckoned among the exports of Egypt at present, but I am acquainted with no author who mentions the place where it is found or made, or who has described the method of preparing it.

The island of Melos, now called Milo, was particularly celebrated on account of its alum, as we learn from Diodorus Siculus, Celsus, Pliny and others, though none was to be found there in the time of Diodorus⁴⁹⁵. This native vitriol has been observed in the grottos of that island by several modern travellers, especially Tournefort⁴⁹⁶, who very properly considers it as the real alum of the ancients.

The islands of Lipara and Strongyle, or, as they are called at present, Lipari and Stromboli, contained so great a quantity of this substance, that the duty on it brought a considerable revenue to the Romans⁴⁹⁷. At one period, Lipari carried on an exclusive trade in alum, and raised the price of it at pleasure; but in that island at present there are neither vitriol nor alum-works. Sardinia, Macedonia, and Spain, where alum was found formerly, still produce a salt known under that name⁴⁹⁸.

When our alum became known, it was considered as a species of the ancient; and as it was purer, and more proper to be used on most occasions, the name of alum⁴⁹⁹ was soon appropriated to it alone. The kinds of alum however known to the ancients, which were green vitriol, maintained a preference in medicine and for dyeing black; and on this account, these impure substances have been still retained in druggists’ shops under the name of misy, sory, &c. But a method was at length found out of procuring thence crystallized martial salts (salts of iron), which obtained the new name of vitriol. This appellation had its rise first in the eleventh or twelfth century; at least I know no writer older than Albertus Magnus by whom it is mentioned or used. Agricola conjectures that it was occasioned by the likeness which the crystals of vitriol had to glass. This is also the opinion of Vossius⁵⁰⁰; and it is very singular that Pliny says nearly the same thing; for he observes, speaking of blue vitriol, the only kind then known, that one might almost take it for glass⁵⁰¹.

By inquiring into the uses to which the ancients applied their alum, I find that it was sometimes employed to secure wooden buildings against fire. This remark I have here introduced to show that this idea, which in modern times has given occasion to many expensive experiments, is not new. Aulus Gellius⁵⁰² relates, from the works of an historian now lost, that Archelaus, one of the generals of Mithridates, washed over a wooden tower with a solution of alum, and by these means rendered it so much proof against fire, that all Sylla’s attempts to set it in flames proved abortive. Many have conjectured that the substance used for this purpose was neither vitriol nor our alum, but rather asbestos, which is often confounded with Atlas-vitriol⁵⁰³; and against this mistake cautions are to be found even in Theophrastus. But it may be asked, With what was the asbestos laid on? By what means were the threads, which are not soluble in water, made fast to the wood? How could a tower be covered with it? I am rather inclined to believe, that a strongly saturated solution of vitriol might have in some measure served to prevent the effects of the fire, at least as long as a thin coat of potters’ earth or flour-paste, which in the present age have been thought deserving of experiments attended with considerable expense. It does not however appear that the invention of Archelaus, which is still retained in some old books⁵⁰⁴, has been often put in practice⁵⁰⁵; for writers on the art of war, such, for example, as Æneas, recommended vinegar to be washed over wood, in order to prevent its being destroyed by fire.

I shall now proceed to the history of our present alum, which was undoubtedly first made in the East. The period of the invention I cannot exactly determine, but I conclude with certainty that it is later than the twelfth century⁵⁰⁶; for John, the son of Serapion, who lived after Rhazes, was acquainted with no other alum than the impure vitriol of Dioscorides⁵⁰⁷. What made the new alum first and principally known was its beneficial use in the art of dyeing, in which it is employed for fixing as well as rendering brighter and more beautiful different colours. This art therefore the Europeans learned from the Orientals, who, even yet, though we have begun to apply chemistry to the improvement of dyeing, are in some respects superior to us, as is proved by the red of Adrianople, their silks and their Turkey leather. The Italians procured their first alum from the Levant, along with other materials for dyeing; but when these countries were taken possession of by the Turks, it grieved the Christians to be obliged to purchase these necessary articles from the common enemy, and bitter complaints on that subject may be seen in the works of various authors. In the course of time the Italians became acquainted with the art of boiling alum; for some of them had rented Turkish alum-works, and manufactured that salt on their own account. They at length found aluminous minerals in their own country, on which they made experiments. These having answered their expectations, they were soon brought into use; and this branch of trade declined afterwards so much in Turkey, that many of the alum-works there were abandoned.

We are told by many historians that the Europeans who first made alum in Italy learned their art, as Augustin Justinian says, at Rocca di Soria, or Rocca in Syria. Neither in books of geography nor in maps, however, can I find any place of this name in Syria. I at first conjectured that Rocca on the Euphrates might be here meant, but at present it appears to me more probable that it is Edessa, which is sometimes called Roha, Raha, Ruha, Orfa, and also Roccha, as has been expressly remarked by Niebuhr⁵⁰⁸. Edessa is indeed reckoned to be in Mesopotamia, but some centuries ago Syria perhaps was understood in a more extended sense. This much at least is certain, that minerals which indicate alum have been often observed by travellers in that neighbourhood.

It appears that the new alum was at first distinguished from the ancient vitriol by the denomination of Rocca, from which the French have made alun de roche, and some of the Germans rotzalaun⁵⁰⁹. Respecting the origin of this name very different conjectures have been formed. Some think it is derived from rocca, which in the Greek signifies a rock, because this salt is by boiling procured from a stone; and these translate the word alumen rupeum, from which the French name is formed⁵¹⁰. Some are of opinion that alum obtained from alum-stone has been so called to distinguish it from that procured from schists, which is generally mixed with more iron than the former⁵¹¹; and others maintain that alum acquired the name of Rocca from the alum-rocks in the neighbourhood of Tolfa⁵¹². It is to be remarked, on the other hand, that Biringoccio, that expert Italian, confesses he does not know whence the name has arisen⁵¹³. For my part I am inclined to adopt the opinion of Leibnitz, that alumen roccæ was that kind first procured from Rocca in Syria; and that this name was afterwards given to every good species of alum, as we at present call the purest Roman alum⁵¹⁴.

In the fifteenth century there were alum-works in the neighbourhood of Constantinople, from which John di Castro, of whom I shall have occasion to speak hereafter, learned his art. May not these alum-works be those visited by Bellon, and of which he has given an excellent description⁵¹⁵? He names the place Cypsella or Chypsilar, and says that the alum in commerce is called alumen Lesbium, or di Metelin. The alum procured from Constantinople at present may perhaps be brought from the same spot; but I am not sufficiently acquainted with its situation to determine that point with certainty, for Büsching makes no mention of it. In some maps I find the names Ypsala and Chipsilar on the western side of the river Mariza, Maritz or Maricheh, which was the Hebrus of the ancients; in others stands the name Scapsiler on the west bank of the sea Bouron; and it is not improbable that these may be all derived from the old Scaptesyle or Scapta Hyla, where, according to the account of Theophrastus, Pliny and others, there were considerable mines.

Another alum-work, no less celebrated in the fifteenth century, was established near the city Phocæa Nova, at present called Foya Nova, not far from the mouth of the Hermus, in the neighbourhood of Smyrna. Of this work, Ducas, who had a house there, has given a particular description, from which we learn that in his time, that is under the reign of Michael Palæologus, it was farmed by Italians, who sold the produce of it to their countrymen, and to the Dutch, French, Spaniards, English, Arabs, Egyptians, and people of Syria. This author relates very minutely in what manner the alum was made, but that work has been long since abandoned⁵¹⁶: alum however made in the neighbourhood is still exported from Smyrna⁵¹⁷. It is much to be wished that ingenious travellers would examine the alum-works in Thrace, around Smyrna, and in Turkey in general, and give an accurate description of them according to the state in which they are at present⁵¹⁸.