Chapter XXI: Book XXXVI: The Natural History of Stones (3)

The fourth variety is known as the Taphiusian aëtites, and is found near Leucas,[2737] at Taphiusa, a locality which lies to the right as you sail from Ithaca towards Cape Leucas. It is met with in the beds of rivers there, and is white and round; having another stone in the interior, the name given to which is “callimus:” none of the varieties of aëtites have a smoother surface than this. Attached to pregnant women or to cattle, in the skins of animals that have been sacrificed, these stones act as a preventive of abortion, care being taken not to remove them till the moment of parturition; for otherwise procidence of the uterus is the result. If, on the other hand, they are not removed at the moment when parturition is about to ensue, that operation of Nature cannot be effected.

CHAP. 40.—SAMIAN STONE: EIGHT REMEDIES.

Samian stone[2738] comes from the same island which produces the earth in praise of which we have spoken already.[2739] It is useful for giving a polish to gold, and it is employed medicinally for the treatment of ulcerations of the eyes, combined with milk in manner already[2740] described. It is good, too, for watery discharges of a chronic nature, from the eyes. Taken internally, it is useful for affections of the stomach, and it has the effect of dispelling vertigo and restoring the spirits when depressed. Some writers are of opinion that this stone may be administered with advantage for epilepsy and strangury; and it is employed as an ingredient in the restoratives known as “acopa.”[2741] The test of its purity is its weight and its whiteness. Some persons will have it that, worn as an amulet, it acts as a preventive of abortion.

CHAP. 41.—ARABIAN STONE; SIX REMEDIES.

Arabian[2742] stone resembles ivory in appearance; and in a calcined state it is employed as a dentifrice.[2743] It is particularly useful for the cure of hæmorrhoidal swellings, applied either in lint or by the aid of linen pledgets.

CHAP. 42.—PUMICE; NINE REMEDIES.

And here, too, I must not omit to give some account of pumice.[2744] This name is very generally given, it is true, to those porous pieces of stone, which we see suspended in the erections known as “musæa,”[2745] with the view of artificially giving them all the appearance of caverns. But the genuine pumice-stones, that are in use for imparting smoothness to the skin of females, and not females only, but men as well, and, as Catullus[2746] says, for polishing books, are found of the finest quality in the islands of Melos and Nisyros[2747] and in the Æolian Isles. To be good, they should be white, as light as possible, porous and dry in the extreme, friable, and free from sand when rubbed.

Considered medicinally, pumice is of a resolvent and desiccative nature; for which purpose it is submitted to calcination, no less than three times, on a fire of pure charcoal, it being quenched as often in white wine. It is then washed, like cadmia,[2748] and, after being dried, is put by for keeping, in a place as free from damp as possible. In a powdered state, pumice is used in ophthalmic preparations more particularly, and acts as a lenitive detergent upon ulcerations of the eyes. It also makes new flesh upon cicatrizations of those organs, and removes all traces of the marks. Some prefer, after the third calcination, leaving the pumice to cool, and then triturating it in wine. It is employed also as an ingredient in emollient poultices, being extremely useful for ulcerations on the head and generative organs; dentifrices, too, are prepared from it. According to Theophrastus,[2749] persons when drinking for a wager are in the habit[2750] of taking powdered pumice first; but they run great risk, he says, if they fail to swallow the whole draught of wine at once; it being of so refrigerative a nature that grape-juice[2751] will absolutely cease to boil if pumice is put into it.

CHAP. 43. (22.)—STONES FOR MORTARS USED FOR MEDICINAL AND OTHER PURPOSES. ETESIAN STONE. THEBAIC STONE. CHALAZIAN STONE.

Authors, too, have paid some attention to the stones in use for mortars, not only those employed for the trituration of drugs and pigments, but for other purposes as well. In this respect they have given the preference to Etesian[2752] stone before all others, and, next to that, to Thebaic stone, already mentioned[2753] as being called “pyrrhopœcilon,” and known as “psaranus” by some. The third rank has been assigned to chrysites,[2754] a stone nearly allied to Chalazian[2755] stone. For medicinal purposes, however, basanites[2756] has been preferred, this being a stone that remits no particles from its surface.[2757]

Those stones which yield a liquid, are generally looked upon as good for the trituration of ophthalmic preparations; and hence it is, that the Æthiopian stone is so much in request for the purpose. Tænarian stone, they say, Phœnician stone, and hæmatites, are good for the preparation of those medicinal compositions in which saffron forms an ingredient; but they also speak of another Tænarian stone, of a dark colour, which, like Parian[2758] stone, is not so well adapted for medicinal purposes. We learn from them, too, that Egyptian alabastrites,[2759] or white ophites,[2760] from the virtues inherent in them, are considered still better adapted for these purposes than the kinds last mentioned. It is this kind of ophites, too, from which vessels, and casks even, are made.

CHAP. 44.—STONE OF SIPHNOS. SOFT STONES.

At Siphnos,[2761] there is a kind of stone[2762] which is hollowed and turned in the lathe, for making cooking-utensils and vessels for keeping provisions; a thing too, that, to my own knowledge,[2763] is done with the green stone[2764] of Comum[2765] in Italy. With reference, however, to the stone of Siphnos, it is a singular fact, that, when heated in oil, though naturally very soft, it becomes hard and black; so great a difference is there in the qualities of stone.

There are some remarkable instances, too, beyond the Alps, of the natural softness of some kinds of stone. In the province of the Belgæ, there is a white stone[2766] which admits of being cut with the saw that is used for wood, and with greater facility even. This stone is used as a substitute for roof-tiles and gutter-tiles, and even for the kind of roofing known as the pavonaceous[2767] style, if that is preferred. Such are the stones that admit of being cut into thin slabs.

CHAP. 45.—SPECULAR STONES.

As to specular[2768] stone—for this, too, is ranked as one of the stones—it admits of being divided with still greater facility, and can be split into leaves as thin as may be desired. The province of Nearer Spain used formerly to be the only one that furnished it—not, indeed, the whole of that country, but a district extending for a hundred miles around the city of Segobrica.[2769] But at the present day, Cyprus, Cappadocia, and Sicily, supply us with it; and, still more recently, it has been discovered in Africa: they are all, however, looked upon as inferior to the stone which comes from Spain. The sheets from Cappadocia are the largest in size; but then they are clouded. This stone is to be found also in the territory of Bononia,[2770] in Italy; but in small pieces only, covered with spots and encrusted in a bed of silex, there being a considerable affinity, it would appear, in their nature.

In Spain, the specular-stone is extracted from shafts sunk in the earth to a very considerable depth; though it is occasionally to be found just beneath the surface, enclosed in the solid rock, and extracted without difficulty, or else cut away from its bed. In most cases, however, it admits of being dug up, being of an isolated nature, and lying in pieces, like rag-stone, but never known as yet to exceed five feet in length. It would appear that this substance is originally a liquid, which, by an animating power in the earth, becomes congealed like crystal; and it is very evident that it is the result of petrifaction, from the fact that, when animals have fallen into the shafts from which it is extracted, the marrow of their bones becomes transformed into stone of a similar nature, by the end of a single winter. In some cases, too, it is found of a black colour: but the white stone has the marvellous property, soft as it is known to be, of resisting the action of the sun and of cold. Nor will it, if it is only protected from accidents, become deteriorated by lapse of time, a thing that is so generally the case with many other kinds of stone that are used for building purposes. The shavings, too, and scales of this stone, have been used of late for another purpose; the Circus Maximus having been strewed with them at the celebration of the games, with the object of producing an agreeable whiteness.

CHAP. 46.—PHENGITES.

During the reign of Nero, there was a stone found in Cappadocia, as hard as marble, white, and transparent even in those parts where red veins were to be seen upon it; a property which has obtained for it the name of “phengites.”[2771] It was with this stone[2772] that Nero rebuilt the Temple of Fortune, surnamed Seia,[2773] originally consecrated by King Servius, enclosing it within the precincts of his Golden Palace.[2774] Hence it was that, even when the doors were closed, there was light in the interior during the day; not transmitted from without, as would be the case through a medium of specular-stone, but having all the appearance of being enclosed within[2775] the building.

In Arabia, too, according to Juba, there is a stone, transparent like glass, which is used for the same purposes as specular-stone.

CHAP. 47.—WHETSTONES.

We must now pass on to the stones that are employed for handicrafts, and, first of all, whetstones for sharpening iron. Of these stones there are numerous varieties; the Cretan stones having been long held in the highest estimation, and the next best being those of Mount Taygetus, in Laconia; both of which are used as hones, and require oil. Among the water-whetstones, the first rank belonged to those of Naxos, and the second to the stones of Armenia, both of them already[2776] mentioned. The stones of Cilicia are of excellent quality, whether used with oil or with water; those of Arsinöe,[2777] too, are very good, but with water only. Whetstones have been found also in Italy, which with water give a remarkably keen edge; and from the countries beyond the Alps, we have the whetstones known as “passernices.”[2778]

To the fourth class belong the hones which give an edge by the agency of human saliva, and are much in use in barbers’ shops. They are worthless, however, for all other purposes, in consequence of their soft and brittle nature: those from the district of Laminium,[2779] in Nearer Spain, are the best of the kind.

CHAP. 48.—TOPHUS.

Among the multitude of stones which still remain undescribed, there is tophus;[2780] material totally unsuited for building purposes, in consequence of its perishableness. Still, however, there are some localities which have no other, Carthage, in Africa, for example. It is eaten away by the emanations from the sea, crumbled to dust by the wind, and shattered by the pelting of the rain: but human industry has found the means of protecting walls of houses built of it, with a coating of pitch, as a plaster of lime would corrode it. Hence it is, that we have the well-known saying, “that the Carthaginians use pitch[2781] for their houses and lime[2782] for their wines,” this last being the method used by them in the preparation of their must.

In the territories of Fidenæ and Alba, in the vicinity of Rome, we find other soft kinds of stone; and, in Umbria and Venetia, there is a stone[2783] which admits of being cut with the teeth of a saw. These stones are easy to be worked, and are capable of supporting a considerable weight, if they are only kept sheltered from the weather. Rain, however, frost, and dew, split them to pieces, nor can they resist the humidity of the sea-air. The stone[2784] of Tibur can stand everything except heat, which makes it crack.

CHAP. 49.—THE VARIOUS KINDS OF SILEX.

The black silex[2785] is in general the best; but in some localities, it is the red, and occasionally the white; as in the Anician quarries at Tarquinii, near Lake Volsinius,[2786] for example, and those at Statonia,[2787] the stone of which is proof against fire even.[2788] These stones, sculptured for monumental purposes, are subject to no deterioration by lapse of time: moulds, too, are made from them, for the purpose of fusing copper. There is a green silex, also, which offers a most powerful resistance to the action of fire, but is never found in any large quantities, and, in all cases, in an isolated form, and not as a constituent part of solid rock. Of the other kinds, the pale silex is but rarely used for erections: being of globular form, it is not liable to injury, but at the same time it is insecure for building purposes, unless it is well braced and tightly held together. Nor yet does river silex offer any greater security, for it always has the appearance of being wet.

CHAP. 50.—OTHER STONES USED FOR BUILDING.

When the nature of stone is doubtful, the proper precaution is, to quarry it in summer, and not to use it for building before the end of a couple of years, leaving it in the meantime to be well seasoned by the weather. The slabs which have been damaged will be found to be better suited for the foundations under ground: while those, on the other hand, which have remained uninjured, may be employed with safety, and exposed to the open air even.

CHAP. 51.—THE VARIOUS METHODS OF BUILDING.

The Greeks construct party-walls, resembling those of brickwork, of hard stone or of silex, squared. This kind of stonework is what they call “isodomon,”[2789] it being ” pseudisodomon”[2790] when the wall is built of materials of unequal dimensions. A third kind of stonework is called “emplecton,”[2791] the two exteriors only being made with regularity, the rest of the material being thrown in at random. It is necessary that the stones should lie over one another alternately, in such a way that the middle of one stone meets the point of junction of the two below it; and this, too, in the middle of the wall, if possible; but if not, at all events, at the sides. When the middle of the wall is filled up with broken stones, the work is known as “diatoichon.”[2792]

The reticulated[2793] kind of building, which is mostly in use at Rome, is very liable to crack.[2794] All building should be done by line and rule, and ought to be strictly on the perpendicular.

CHAP. 52. (23.)—CISTERNS.

Cisterns should be made of five parts of pure, gravelly, sand, two of the very strongest quicklime, and fragments of silex not exceeding a pound each in weight; when thus incorporated, the bottom and sides should be well beaten with iron rammers. The best plan, too, is to have the cisterns double; so that all superfluities may settle in the inner cistern, and the water filter through, as pure as possible, into the outer one.

CHAP. 53.—QUICK-LIME.

Cato[2795] the Censor disapproves of lime prepared from stones of various colours: that made of white stone is the best. Lime prepared from hard stone is the best for building purposes, and that from porous stone for coats of plaster. For both these purposes, lime made from silex is equally rejected. Stone that has been extracted from quarries furnishes a better lime than that collected from the beds of rivers; but the best of all is the lime that is obtained from the molar-stone,[2796] that being of a more unctuous nature than the others. It is something truly marvellous, that quick-lime, after the stone has been subjected to fire, should ignite on the application of water!

CHAP. 54.—THE VARIOUS KINDS OF SAND. THE COMBINATIONS OF SAND WITH LIME.

There are three kinds of sand: fossil[2797] sand, to which one-fourth part of lime should be added;[2798] river sand; and sea sand; to both of which last, one third of lime should be added. If, too, one third of the mortar is composed of bruised earthenware, it will be all the better. Fossil sand is found in the districts that lie between the Apennines and the Padus, but not in the parts beyond sea.

CHAP. 55.—DEFECTS IN BUILDING. PLASTERS FOR WALLS.

The great cause of the fall of so many buildings in our City, is, that through a fraudulent abstraction of the lime, the rough work is laid without anything to hold it together. The older, too, the mortar is, the better it is in quality. In the ancient laws for the regulation of building, no contractor was to use mortar less than three months old; hence it is, that no cracks have disfigured the plaster coatings of their walls. These stuccos will never present a sufficiently bright surface, unless there have been three layers of sanded mortar, and two of marbled[2799] mortar upon that. In damp localities and places subject to exhalations from the sea, it is the best plan to substitute ground earthenware mortar for sanded mortar. In Greece, it is the practice, first to pound the lime and sand used for plastering, with wooden pestles in a large trough. The test by which it is known that marbled mortar has been properly blended, is its not adhering to the trowel; whereas, if it is only wanted for white-washing, the lime, after being well slaked with water, should stick like glue. For this last purpose, however, the lime should only be slaked in lumps.

At Elis, there is a Temple of Minerva, which was pargetted, they say, by Panænus, the brother of Phidias, with a mortar that was blended with milk and saffron:[2800] hence it is, that, even at the present day, when rubbed with spittle on the finger, it yields the smell and flavour of saffron.

CHAP. 56.—COLUMNS. THE SEVERAL KINDS OF COLUMNS.

The more closely columns are placed together, the thicker they appear to be. There are four different kinds of pillars. Those of which the diameter at the foot is one-sixth part of the height, are called Doric. When the diameter is one-ninth, they are Ionic; and when it is one-seventh, Tuscan. The proportions in the Corinthian are the same as those of the Ionic; but they differ in the circumstance that the Corinthian capitals are of the same height as the diameter at the foot, a thing that gives them a more slender appearance; whereas, in the Ionic column, the height of the capital is only one-third of the diameter at the foot. In ancient times the rule was, that the columns should be one-third of the breadth of the temple in height.

It was in the Temple of Diana, at Ephesus, as originally built, that spirals[2801] were first placed beneath, and capitals added: and it was determined that the diameter of the shafts should be one-eighth of their height, and that the spirals should be one-half of the diameter in height, the upper extremity of the shaft being one-seventh less in diameter than the foot. In addition to these columns, there are what are called “Attic” columns, quadrangular, and with equal sides.

CHAP. 57. (24.)—FIVE REMEDIES DERIVED FROM LIME.

Lime is also employed very extensively in medicine. For this purpose, fresh lime is selected, which has not been slaked with water. Its properties are caustic, resolvent, and attractive; and it prevents serpiginous ulcers from spreading, being incorporated with vinegar and oil of roses, for the purpose. When this has been effected, it is tempered with wax and oil of roses, and applied to promote cicatrization. In combination with honey, and liquid resin, or hogs’ lard, lime is curative of sprains and scrofulous sores.

CHAP. 58.—MALTHA.

Maltha[2802] is a cement prepared from fresh lime; lumps of which are quenched in wine, and then pounded with hogs’ lard and figs, both of them, mollifying substances.[2803] It is the most tenacious of all cements, and surpasses stone in hardness. Before applying the maltha, the substance upon which it is used must be well rubbed with oil.

CHAP. 59.—GYPSUM.

Gypsum[2804] has a close affinity with limestone, and there are numerous varieties of it. One kind is prepared from a calcined[2805] stone, as in Syria, and at Thurii, for example. In Cyprus and at Perrhæbia,[2806] gypsum is dug out of the earth, and at Tymphæa[2807] it is found just below the level of the soil. The stone that is calcined for this purpose, ought to be very similar to alabastrites,[2808] or else of a grain like that of marble. In Syria, they select the hardest stones for the purpose, and calcine them with cow-dung, to accelerate the process. Experience has proved, however, that the best plaster of all is that prepared from specular-stone,[2809] or any other stone that is similarly laminated. Gypsum, when moistened, must be used immediately, as it hardens with the greatest rapidity; it admits, however, of being triturated over again, and so reduced to powder. It is very useful for pargetting, and has a pleasing effect when used for ornamental figures and wreaths in buildings.

There is one remarkable fact connected with this substance; Caius Proculeius,[2810] an intimate friend of the Emperor Augustus, suffering from violent pains in the stomach, swallowed gypsum, and so put an end to his existence.[2811]

CHAP. 60. (25.)—PAVEMENTS. THE ASAROTOS ŒCOS.

Pavements are an invention of the Greeks, who also practised the art of painting them, till they were superseded by mosaics.[2812] In this last branch of art, the highest excellence has been attained by Sosus,[2813] who laid, at Pergamus, the mosaic pavement known as the “Asarotos œcos;”[2814] from the fact that he there represented, in small squares of different colours, the remnants of a banquet lying upon the pavement, and other things which are usually swept away with the broom, they having all the appearance of being left there by accident. There is a dove also, greatly admired, in the act of drinking, and throwing the shadow of its head upon the water; while other birds are to be seen sunning and pluming themselves, on the margin of a drinking-bowl.

CHAP. 61.—THE FIRST PAVEMENTS IN USE AT ROME.

The first pavements, in my opinion, were those now known to us as barbaric and subtegulan[2815] pavements, a kind of work that was beaten down with the rammer: at least if we may form a judgment from the name[2816] that has been given to them. The first diamonded[2817] pavement at Rome was laid in the Temple of Jupiter Capitolinus, after the commencement of the Third Punic War. That pavements had come into common use before the Cimbric War, and that a taste for them was very prevalent, is evident from the line of Lucilius—

“With checquered emblems like a pavement marked.”[2818]

CHAP. 62.—TERRACE-ROOF PAVEMENTS.

The Greeks have also invented terrace-roof[2819] pavements, and have covered their houses with them; a thing that may easily be done in the hotter climates, but a great mistake in countries where the rain is apt to become congealed. In making these pavements, the proper plan is to begin with two layers of boards, running different ways, and nailed at the extremities, to prevent them from warping. Upon this planking a rough-work must be laid, one-fourth of which consists of pounded pottery: and upon this, another bed of rough-work, two-fifths composed of lime, a foot in thickness, and well beaten down with the rammer. The nucleus[2820] is then laid down, a bed six fingers in depth; and upon that, large square stones, not less than a couple of fingers in thickness; an inclination being carefully observed, of an inch and a half to every ten feet. This done, the surface is well rubbed down with a polishing stone. The general opinion is, that oak[2821] should never be used for the planking, it being so very liable to warp; and it is considered a good plan to cover the boards with a layer of fern or chaff, that they may be the better able to resist the action of the lime. It is necessary, too, before putting down the planking, to underset it with a bed of round pebbles. Wheat-ear[2822] tesselated pavements are laid down in a similar manner.

CHAP. 63.—GRÆCANIC PAVEMENTS.

We must not omit here one other kind of pavement, that known as the “Græcanic.” The ground is well rammed down, and a bed of rough work, or else broken pottery, is then laid upon it. Upon the top of this, a layer of charcoal is placed, well trodden down with a mixture of sand, lime, and ashes; care being taken, by line and rule, to give it a uniform thickness of half a foot. The surface then presents the ordinary appearance of the ground; but if it is well rubbed with the polishing-stone, it will have all the appearance of a black pavement.

CHAP. 64.—AT WHAT PERIOD MOSAIC PAVEMENTS WERE FIRST INVENTED. AT WHAT PERIOD ARCHED ROOFS WERE FIRST DECORATED WITH GLASS.

Mosaic[2823] pavements were first introduced in the time of Sylla; at all events, there is still in existence a pavement, formed of small segments, which he ordered to be laid down in the Temple of Fortune, at Præneste. Since his time, these mosaics have left the ground for the arched roofs of houses, and they are now made of glass. This, however, is but a recent invention; for there can be no doubt that, when Agrippa ordered the earthenware walls of the hot baths, in the Thermæ which he was building at Rome, to be painted in encaustic, and had the other parts coated with pargetting, he would have had the arches decorated with mosaics in glass, if the use of them had been known; or, at all events, if from the walls of the Theatre of Scaurus, where it figured, as already[2824] stated, glass had by that time come to be used for the arched roofs of apartments. It will be as well, therefore, to give some account, also, of glass.

CHAP. 65. (26.)—THE ORIGIN OF GLASS.

In Syria there is a region known as Phœnice,[2825] adjoining to Judæa, and enclosing, between the lower ridges of Mount Carmelus, a marshy district known by the name of Cendebia. In this district, it is supposed, rises the river Belus,[2826] which, after a course of five miles, empties itself into the sea near the colony of Ptolemaïs. The tide of this river is sluggish, and the water unwholesome to drink, but held sacred for the observance of certain religious ceremonials. Full of slimy deposits, and very deep, it is only at the reflux of the tide that the river discloses its sands; which, agitated by the waves, separate themselves from their impurities, and so become cleansed. It is generally thought that it is the acridity of the sea-water that has this purgative effect upon the sand, and that without this action no use could be made of it. The shore upon which this sand is gathered is not more than half a mile in extent; and yet, for many ages, this was the only spot that afforded the material for making glass.

The story is, that a ship, laden with nitre,[2827] being moored upon this spot, the merchants, while preparing their repast upon the sea-shore, finding no stones at hand for supporting their cauldrons, employed for the purpose some lumps of nitre which they had taken from the vessel. Upon its being subjected to the action of the fire, in combination with the sand of the sea-shore, they beheld transparent streams flowing forth of a liquid hitherto unknown: this, it is said, was the origin of glass.[2828]

CHAP. 66.—THE VARIOUS KINDS OF GLASS, AND THE MODE OF MAKING IT.

In process of time, as human industry is ingenious in discovering, it was not content with the combination of nitre, but magnet-stone[2829] began to be added as well; from the impression that it attracts liquefied[2830] glass as well as iron. In a similar manner, too, brilliant stones of various descriptions came to be added in the melting, and, at last, shells and fossil sand. Some authors tell us, that the glass of India is made of broken crystal, and that, in consequence, there is none that can be compared to it.

In fusing it, light and dry wood is used for fuel, Cyprian copper and nitre being added to the melting, nitre of Ophir[2831] more particularly. It is melted, like copper, in contiguous furnaces, and a swarthy mass of an unctuous appearance is the result. Of such a penetrating nature is the molten glass, that it will cut to the very bone any part of the body which “it may come near, and that, too, before it is even felt. This mass is again subjected to fusion in the furnace, for the purpose of colouring it; after which, the glass is either blown into various forms, turned in a lathe, or engraved[2832] like silver. Sidon was formerly famous for its glass-houses, for it was this place that first invented[2833] mirrors.

Such was the ancient method of making glass: but, at the present day, there is found a very white sand for the purpose, at the mouth of the river Volturnus, in Italy. It spreads over an extent of six miles, upon the sea-shore that lies between Cumæ and Liternum, and is prepared for use by pounding it with a pestle and mortar; which done, it is mixed with three parts of nitre, either by weight or measure, and, when fused, is transferred to another furnace. Here it forms a mass of what is called “hammonitrum;” which is again submitted to fusion, and becomes a mass of pure, white, glass. Indeed, at the present day, throughout the Gallic and Spanish provinces even, we find sand subjected to a similar process. In the reign of Tiberius, it is said, a combination was devised which produced a flexible[2834] glass; but the manufactory of the artist was totally destroyed, we are told, in order to prevent the value of copper, silver, and gold, from becoming depreciated.[2835] This story, however, was, for a long time, more widely spread than well authenticated. But be it as it may, it is of little consequence; for, in the time of the Emperor Nero, there was a process discovered, by which two small glass cups were made, of the kind called “petroti,”[2836] the price of which was no less than six thousand sesterces!

CHAP. 67.—OBSIAN GLASS AND OBSIAN STONE.

Among the various kinds of glass, we may also reckon Obsian glass, a substance very similar to the stone[2837] which Obsius discovered in Æthiopia. This stone is of a very dark colour, and sometimes transparent; but it is dull to the sight, and reflects, when attached as a mirror to walls, the shadow of the object rather than the image. Many persons use it[2838] for jewellery, and I myself have seen solid statues[2839] in this material of the late Emperor Augustus, of very considerable thickness. That prince consecrated, in the Temple of Concord, as something marvellous, four figures of elephants made of Obsian stone. Tiberius Cæsar, too, restored to the people of Heliopolis, as an object of ceremonial worship, an image in this stone, which had been found among the property left by one of the præfects of Egypt. It was a figure of Menelaüs; a circumstance which goes far towards proving that the use of this material is of more ancient date than is generally supposed, confounded as it is at the present day with glass, by reason of its resemblance. Xenocrates says that Obsian stone is found in India also, and in Samnium in Italy; and that it is a natural product of Spain, upon the coasts which border on the Ocean.[2840]

There is an artificial Obsian stone, made of coloured glass for services for the table; and there is also a glass that is red all through, and opaque, known as “hæmatinum.”[2841] A dead white glass, too, is made, as also other kinds in imitation of murrhine[2842] colour, hyacinthine, sapphire, and every other tint: indeed, there is no material of a more pliable[2843] nature than this, or better suited for colouring. Still, however, the highest value is set upon glass that is entirely colourless and transparent, as nearly as possible resembling crystal, in fact. For drinking-vessels, glass has quite superseded the use of silver and gold; but it is unable to stand heat unless a cold liquid is poured in first. And yet, we find that globular glass vessels, filled with water, when brought in contact with the rays of the sun,[2844] become heated to such a degree as to cause articles of clothing to ignite. When broken, too, glass admits of being joined by the agency of heat; but it cannot be wholly fused without being pulverized into small fragments,[2845] as we see done in the process of making the small checquers, known as “abaculi,” for mosaic work; some of which are of variegated colours, and of different shapes. If glass is fused with sulphur, it will become as hard as stone.

CHAP. 68. (27.)—MARVELLOUS FACTS CONNECTED WITH FIRE.

Having now described all the creations of human ingenuity, reproductions, in fact, of Nature by the agency of art, it cannot but recur to us, with a feeling of admiration, that there is hardly any process which is not perfected through the intervention of fire. Submit to its action some sandy soil, and in one place it will yield glass, in another silver, in another minium, and in others, again, lead and its several varieties, pigments, and numerous medicaments. It is through the agency of fire that stones[2846] are melted into copper; by fire that iron is produced, and subdued to our purposes; by fire that gold is purified; by fire, too, that the stone is calcined, which is to hold together the walls of our houses.

Some materials, again, are all the better for being repeatedly submitted to the action of fire; and the same substance will yield one product at the first fusion, another at the second, and another at the third.[2847] Charcoal, when it has passed through fire and has been quenched, only begins to assume its active properties; and, when it might be supposed to have been reduced to annihilation, it is then that it has its greatest energies. An element this, of immense, of boundless[2848] power, and, as to which, it is a matter of doubt whether it does not create even more than it destroys!

CHAP. 69.—THREE REMEDIES DERIVED FROM FIRE AND FROM ASHES.

Fire even has certain medicinal virtues of its own. When pestilences prevail, in consequence of the obscuration[2849] of the sun, it is a well-known fact, that if fires are lighted, they are productive of beneficial results in numerous ways. Empedocles and Hippocrates have proved this in several passages.

“For convulsions or contusions of the viscera,” says M. Varro—for it is his own words that I use—“let the hearth be your medicine-box; for lie of ashes,[2850] taken from thence, mixed with your drink, will effect a cure. Witness the gladiators, for example, who, when disabled at the Games, refresh themselves with this drink.” Carbuncle too, a kind of disease which, as already[2851] stated, has recently carried off two persons of consular rank, admits of being successfully treated with oak-charcoal,[2852] triturated with honey. So true is it that things which are despised even, and looked upon as so utterly destitute of all virtues, have still their own remedial properties, charcoal and ashes for example.

CHAP. 70.—PRODIGIES CONNECTED WITH THE HEARTH.

I must not omit too, one portentous fact connected with the hearth, and famous in Roman history. In the reign of Tarquinius Priscus, it is said, there appeared upon his hearth a resemblance of the male generative organ in the midst of the ashes. The captive Ocrisia, a servant of Queen Tanaquil, who happened to be sitting there, arose from her seat in a state of pregnancy, and became the mother of Servius Tullius, who eventually succeeded to the throne.[2853] It is stated, too, that while the child was sleeping in the palace, a flame was seen playing round his head; the consequence of which was, that it was believed that the Lar of the household was his progenitor. It was owing to this circumstance, we are informed, that the Compitalia,[2854] games in honour of the Lares, were instituted.

SUMMARY.—Remedies mentioned, eighty-nine. Facts and narratives, four hundred and thirty-four.

ROMAN AUTHORS QUOTED.—M. Varro,[2855] Cælius,[2856] Galba,[2857] Cincius,[2858] Mucianus,[2859] Nepos Cornelius,[2860] L. Piso,[2861] Q. Tubero,[2862] Fabius Vestalis,[2863] Annius Fetialis,[2864] Fabianus,[2865] Seneca,[2866] Cato the Censor,[2867] Vitruvius.[2868]

FOREIGN AUTHORS QUOTED.—Theophrastus,[2869] Pasiteles,[2870] King Juba,[2871] Nicander,[2872] Sotacus,[2873] Sudines,[2874] Alexander[2875] Polyhistor, Apion,[2876] Plistonicus,[2877] Duris,[2878] Herodotus,[2879] Euhemerus,[2880] Aristagoras,[2881] Dionysius,[2882] Artemidorus,[2883] Butoridas,[2884] Antisthenes,[2885] Demetrius,[2886] Demoteles,[2887] Lyceas.[2888]