Delphi Complete Works of Pliny the Elder

by Pliny the Elder

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  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 stone before all others, and, next to that, to Thebaic stone, already mentioned as being called “pyrrhopœcilon,” and known as “psaranus” by some. The third rank has been assigned to chrysites, a stone nearly allied to Chalazian stone. For medicinal purposes, however, basanites has been preferred, this being a stone that remits no particles from its surface.

  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 stone, is not so well adapted for medicinal purposes. We learn from them, too, that Egyptian alabastrites, or white ophites, 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.

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  CHAP. 44.

  STONE OF SIPHNOS. SOFT STONES.

  At Siphnos, there is a kind of stone 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, is done with the green stone of Comum 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 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 style, if that is preferred. Such are the stones that admit of being cut into thin slabs.

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  CHAP. 45.

  SPECULAR STONES.

  As to specular 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 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, 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 ragstone, 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.

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  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.” It was with this stone that Nero rebuilt the Temple of Fortune, surnamed Seia, originally consecrated by King Servius, enclosing it within the precincts of his Golden Palace. 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 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.

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  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 mentioned. The stones of Cilicia are of excellent quality, whether used with oil or with water; those of Arsinöe, 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.”

  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, in Nearer Spain, are the best of the kind.

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  CHAP. 48.

  TOPHUS.

  Among the multitude of stones which still remain undescribed, there is tophus; a 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 for their houses and lime 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 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 of Tibur can stand everything except heat, which makes it crack.

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  CHAP. 49.

  THE VARIOUS KINDS OF SILEX..

  The black silex is in general the best; but in some localities, it is the red, and occasionally the wh
ite; as in the Anician quarries at Tarquinii, near Lake Volsinius, for example, and those at Statonia, the stone of which is proof against fire even. 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.

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  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.

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  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,” it being “pseudisodomon” when the wall is built of materials of unequal dimensions. A third kind of stonework is called “emplecton,” 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.”

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

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  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.

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  CHAP. 53.

  QUICK-LIME.

  Cato 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, 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!

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  CHAP. 54.

  THE VARIOUS KINDS OF SAND. THE COMBINATIONS OF SAND WITH LIME.

  There are three kinds of sand: fossil sand, to which one-fourth part of lime should be added; 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.

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  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 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: hence it is, that, even at the present day, when rubbed with spittle on the finger, it yields the smell and flavour of saffron.

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  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 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.

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  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.

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  CHAP. 58.

  MALTHA.

  Maltha 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. 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.

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  CHAP. 59.

  gypsum.

  Gypsum has a close affinity with limestone, and there are numerous varieties of it. One kind is prepared from a calcined stone, as in Syria, and at Thurii, for example. In Cyprus and at Perrhæbia, gypsum is dug out of the earth, and a
t Tymphæ 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, 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, 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, an intimate friend of the Emperor Augustus, suffering from violent pains in the stomach, swallowed gypsum, and so put an end to his existence.