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The History of Chemistry. Thomas Thomson
Читать онлайн.Название The History of Chemistry
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isbn 4064066382971
Автор произведения Thomas Thomson
Жанр Математика
Издательство Bookwire
Cinnabar was occasionally used as an external medicine; but Pliny disapproves of it, assuring his readers that quicksilver and all its preparations are virulent poisons. No other mercurial preparations except cinnabar and the amalgam of mercury seem to have been known to the ancients.62
9. The ancients were unacquainted with the metal to which we at present give the name of antimony; but several of the ores of that metal, and of the products of these ores were not altogether unknown to them. From the account of stimmi and stibium, by Dioscorides63 and Pliny,64 there can be little doubt that these names were applied to the mineral now called sulphuret of antimony or crude antimony. It is found most commonly, Pliny says, among the ores of silver, and consists of two kinds, the male and the female; the latter of which is most valued.
This pigment was known at a very early period, and employed by the Asiatic ladies in painting their eyelashes, or rather the insides of their eyelashes, black. Thus it is said of Jezebel, that when Jehu came to Jezreel she painted her face. The original is, she put her eyes in sulphuret of antimony.65 A similar expression occurs in Ezekiel, “For whom thou didst wash thyself, paintedst thy eyes”—literally, put thy eyes in sulphuret of antimony.66 This custom of painting the eyes black with antimony was transferred from Asia to Greece, and while the Moors occupied Spain it was employed by the Spanish ladies also. It is curious that the term alcohol, at present confined to spirit of wine, was originally applied to the powder of sulphuret of antimony.67 The ancients were in the habit of roasting sulphuret of antimony, and thus converting it into an impure oxide. This preparation was also called stimmi and stibium. It was employed in medicine as an external application, and was conceived to act chiefly as an astringent; Dioscorides describes the method of preparing it. We see, from Pliny’s account of stibium, that he did not distinguish between sulphuret of antimony and oxide of antimony.68
9. Some of the compounds of arsenic were also known to the ancients; though they were neither acquainted with this substance in the metallic state, nor with its oxide; the nature of which is so violent that had it been known to them it could not have been omitted by Dioscorides and Pliny.
The word σανδαραχη (sandarache) occurs in Aristotle, and the term αρῥενιχον (arrhenichon) in Theophrastus.69 Dioscorides uses likewise the same name with Aristotle. It was applied to a scarlet-coloured mineral, which occurs native, and is now known by the name of realgar. It is a compound of arsenic and sulphur. It was employed in medicine both externally and internally, and is recommended by Dioscorides, as an excellent remedy for an inveterate cough.
Auripigmentum and arsenicum were names given to the native yellow sulphuret of arsenic. It was used in the same way, and considered by Dioscorides and Pliny as of the same nature with realgar. But there is no reason for supposing that the ancients were acquainted with the compositions of either of these bodies; far less that they had any suspicion of the existence of the metal to which we at present give the name of arsenic.
Such is a sketch of the facts known to the ancients respecting metals. They knew the six malleable metals which are still in common use, and applied them to most of the purposes to which the moderns apply them. Scarcely any information has been left us of the methods employed by them to reduce these metals from their ores. But unless the ores were of a much simpler nature than the modern ores of these metals, of which we have no evidence, the smelting processes with which the ancients were familiar, could scarcely have been contrived without a knowledge of the substances united with the different metals in their ores, and of the means by which these foreign bodies could be separated, and the metals isolated from all impurities. This doubtless implied a certain quantity of chemical knowledge, which having been handed down to the moderns, served as a foundation upon which the modern science of chemistry was gradually reared: at the same time it will be admitted that this foundation was very slender, and would of itself have led to little. Most of the oxides, sulphurets, &c., and almost all the salts into which these metallic bodies enter, were unknown to the ancients.
Besides the working in metals there were some other branches of industry practised by the ancients, so intimately connected with chemical science, that it would be improper to pass them over in silence. The most important of these are the following:
II.—COLOURS USED BY PAINTERS.
It is well known that the ancient Grecian artists carried the art of painting to the highest degree of perfection, and that their paintings were admired and sought after by the most eminent and accomplished men of antiquity; and Pliny gives us a catalogue of a great number of first-rate pictures, and a historical account of a vast many celebrated painters of antiquity. In his own time, he says, the art of painting had lost its importance, statues and tablets having came in place of pictures.
Two kinds of colours were employed by the ancients; namely, the florid and the austere. The florid colours, as enumerated by Pliny, were minium, armenium, cinnaberis, chrysocolla, purpurissum, and indicum purpurissum.
The word minium as used by Pliny means red lead; though Dioscorides employs it for bisulphuret of mercury or cinnabar.
Armenium was obviously an ochre, probably of a yellow or orange colour.
Cinnaberis was bisulphuret of mercury, which is known to have a scarlet colour. Dioscorides employs it to denote a vegetable red colour, probably similar to the resin at present called dragon’s blood.
Chrysocolla was a green-coloured paint, and from Pliny’s description of it, could have been nothing else than carbonate of copper or malachite.
Purpurissum was a lake, as is obvious from the account of its formation given by Pliny. The colouring matter is not specified, but from the term used there can be little doubt that it was the liquor from the shellfish that yielded the celebrated purple dye of the Tyrians.
Indicum purpurissum was probably indigo. This might be implied from the account of it given by Pliny.
The austere colours used by the ancient painters were of two kinds, native and artificial. The native were sinopis, rubrica, parætonium, melinum, eretria, auripigmentum. The artificial were, ochra, cerussa usta, sandaracha, sandyx, syricum, atramentum.
Sinopis is the red substance now known by the name of reddle, and used for marking. On that account it is sometimes called red chalk. It was found in Pontus, in the Balearian islands, and in Egypt. The price was three denarii, or 1s. 11¼d. the pound weight. The most famous variety of sinopis was from the isle of Lemnos; it was sold sealed and stamped: hence it was called sphragis. It was employed to adulterate minium. In medicine it was used to appease inflammation, and as an antidote to poison.
Ochre is merely sinopis heated in a covered vessel. The higher the temperature to which it has been exposed the better it is.
Leucophorum is a compound of 6 lbs. sinopis of Pontus, 10 lbs. siris, 2 lbs. melinum, triturated together for thirty days. It was used to make gold adhere to wood.
Rubrica from the name, was probably a red ochre.
Parætonium was a white colour, so called from a place in Egypt, where it was found. It was obtained also in the island of Crete, and in Cyrene. It was said to be a combination of the froth of the sea consolidated with mud. It consisted probably of carbonate of lime. Six pounds of it cost only one denarius.
Melinum