History of Chemistry (Thorpe 1909, NY & London)/Volume I/Chapter I
HISTORY OF CHEMISTRY
CHAPTER I
The Chemistry of the Ancients
CHEMISTRY, as an art, was practised thousands of years before the Christian era; as a science, it dates no further back than the middle of the seventeenth century. The monumental records of Egypt and the accounts left us by Herodotus and other writers show that the ancient Egyptians, among the earliest nations of whom we have any records, had a considerable knowledge of processes essentially chemical in their nature. Their priests were adepts in certain chemical arts, and chemical laboratories were occasionally attached to their temples, as at Thebes, Memphis, and Heliopolis. It is to be supposed, too, that in a cultured class, as the priesthood undoubtedly was, there would be now and again curious and ingenious persons who would speculate on the nature and causes of the phenomena which they observed. But there is no certain evidence that the Egyptians ever pursued chemistry in the spirit of science, or even in the manner in which they and the Chaldæans followed, for example, astronomy or mathematics. The operations of chemistry as performed by them were of the nature of manufacturing processes, empirical in character and utilitarian in result. It was comparatively late in the world's history that men were found willing to occupy themselves in chemical pursuits in order to gain an insight into the nature of chemical change, and to learn the causes and conditions of its action.
Although we have cited the ancient Egyptians as practising the chemical arts, there is no proof that these arts actually originated with them. China, India, Chaldæa have each in turn been regarded as the birthplace of the various technical processes from which chemistry may be said to have taken its rise. Nevertheless, it is mainly from Egyptian records, or from writings avowedly based on information from Egyptian sources, that such knowledge as we possess of the earliest chemical processes is derived. It is significant that the word “chemistry” has its origin in chemi, “the black land,” the ancient name for Egypt. The art itself was constantly spoken of as the “Egyptian art.”
“The word chemistry,” says Boerhaave in the Prolegomena of his New Method of Chemistry
(Shaw and Chambers's translation, London, 1727),
in Greek should be wrote χημία, and in Latin and English chemia and chemistry; not as usual, chymia and chymistry.
The first author in whom the word is found is Plutarch, who lived under the Emperors Domitian, Nerva, and Trajan. That philosopher, in his treatise of Isis and Osiris, takes occasion to observe that Egypt, in the sacred dialect of the country, was called by the same name as the black of the eye—viz., χημία—by which he seems to intimate that the word chemia in the Egyptian language signified black, and that the country, Egypt, might take its denomination from the blackness of the soil.
But [continues Boerhaave] the etymology and grammatical signification of the name is not so easily dispatched. The critics and antiquaries, among whom it has been a great subject of inquiry, will not let it pass without some further disquisition. Instead of black, some will have it originally denote secret, or occult; and hence derive it from the Hebrew chaman, or haman—a mystery, whose radix is cham. And, accordingly, Plutarch observes that Egypt, in the same sacred dialect, is sometimes wrote in Greek χαμία—chamia; whence the word is easily deduced further from Cham, eldest son of Noah, by whom Egypt was first peopled after the deluge, and from whom, in the Scripture style, it is called the land of Cham, or Chem. Now, that chaman, or haman, properly signifies secret appears from the same Plutarch, who, mentioning an ancient author named Menethes Sibonita, who had asserted that Ammon and Hammon were used to denote the god of Egypt, Plutarch takes this occasion to observe that in the Egyptian language anything secret or occult was called by the same name, ἅμμον—Hammon. . . . Lastly, the learned Bochart, keeping to the same sense of the word, chooses to derive it from the Arabic chema, or kema—to hide; adding that there is an Arabic book of secrets called by the same name Kemi.
From the whole of which Boerhaave gathers that chemistry was thus originally denominated because it was considered of old as “not fit to be divulged to the populace, but treasured up as a religious secret.”
If we are to credit Zozimus the Panopolite, who is said to have lived about the beginning of the fifth century, there were sound reasons for thus treasuring up chemistry as a religious secret, since, as it sprang from the pretium amoris, its origin was not too reputable. “What the divine writings relate is that the angels, enflamed with the desire of women, instructed ’em in all the works and mysteries of nature. For which indiscretion they were excluded heaven, as having taught men things unfit for ’em to know.” And Scaliger asserts that “Hermes testifies as much; and all our learning, both open and occult, confirms the account.” But who Hermes was, adds that author, is hard to say, for none of his writings has survived to our age, “that lately published in Italy under the name of Hermes Trismegistus being a manifest forgery.”
This legend of the “feministic” origin of chemistry is in reality much older than the fifth century of our era, and is but a variant of that which, according to Jewish writers, led to the expulsion of man from Paradise. A similar myth was current among the Phœnicians, Persians, Greeks, and Magi. We trace it in the legend of Sibylla, who demanded, as the price of her favour to Phœbus, not only length of years, but a knowledge of the divine arcanum. Some of the ecclesiastics who elaborated these myths are particular in their accounts of the mysteries thus imparted. They included the use of charms, a knowledge of gold and silver and precious stones, the art of dyeing, of painting the eyebrows, etc.—the kind of arcana, in fact, which women in all ages were presumably most keen to know. It is, however, significant that in all allusions to chemia, even after the translation of the seat of the Roman Empire to Constantinople, it is implied that a knowledge of it was a sacred mystery to be known only to the priesthood, and jealously guarded by them. It was characteristic of writers who had affixed an eternal stigma on Eve to make the sex in general answerable for an illicit knowledge of “things unfit for men to know.”
For, in reality, chemistry originated with men, and it was not so much in the love of women as of wine that it took its rise.
The manufacture of alcohol by processes of fermentation is probably the oldest of the chemical arts. The word wine means, in fact, a product of fermentation. Mosaic history relates that Noah, soon after he got to dry land, “planted a vineyard and drank of the wine,” with results that would appear to show that the potency of wine was not unfamiliar to him. Diodorus Siculus, who studied Egyptian antiquities when Egypt was a Roman province, states that the ancient Egyptians ascribed the origin of wine to Osiris. It was a sacrificial offering even in the earliest times, as was bread. Wine seems to have been prepared by the Chinese as far back as the time of the Emperor Yü, circa 2220 B.C. Beer was manufactured in Egypt in the time of Senwosret III. (Sesostris) B.C. 1880.
The Egyptians were skilled in dyeing and in the manufacture of leather, and in the production and working of metals and alloys. They were familiar with the methods of tempering iron. They made glass, artificial gems, and enamels. The oldest known enamel was found as an amulet on the Egyptian Queen Aahotep (1700 B.C.), and glass beads were made before the time of Thutmosis III. (1475 B.C.). The Jews knew of gold, silver, copper, iron, lead, and tin. Indeed, it is through them and the Phoenicians, who were among the earliest of traders, that Europe was gradually made acquainted with many technical products of Eastern origin.
The beginnings of the art of extracting and working of metals are lost in the mists of antiquity; the chemistry of metals, indeed, has been said to be almost coeval with mankind. Diodorus Siculus found traditions in Egypt as to the first inventor of metallurgical processes identical with that of the son of Lamech and Zillah, Tubalcain, or Tuval-cain, of the Hebrews—the Vulcan of the Romans.
Gold was undoubtedly one of the earliest metals to be made use of by men, as it probably was one of the first to be discovered. It occurs free in nature, and is met with in many rocks and in the sands of rivers. Its colour, lustre, and density would early attract attention to it; and its malleability and ductility and the ease with which it could be fashioned, together with its unalterability, would render it valuable. Ethiopian and Nubian gold were known from the earliest times, and quartz crushing and gold washing were practised by the Egyptians. Representations of these processes have been found on Egyptian tombs dating from 2500 B.C. Gold-wire was used by the Egyptians for embroidery, and they practised plating, gilding, and inlaying as far back as 2000 B.C.
Silver also was employed by them, and appears, like gold, to have been coined into money. It was originally known as “white gold.” Some of the oldest coins in existence are alloys of silver and gold, obtained probably by the fusion of naturally occurring argentiferous gold, such as the pale gold of the Pactolus. Such an alloy was termed electrum, from its resemblance in colour to amber.
Copper is also found to a limited extent in the metallic state, but probably the greater part of that used by the ancients was obtained from its ores, which are comparatively abundant and readily smelted. It was also used for coinage by the Egyptians, and was fashioned by them into a variety of utensils and implements. The older writers drew no clear distinction between copper, bronze, and brass, and the terms designating them (oes and χαλκός are frequently employed; as by Pliny, indiscriminately. The statement in Deut. viii. 9—“Out of whose hills thou mayest dig brass”—obviously cannot mean an alloy of copper and zinc, since this does not occur naturally.
Pure copper is too soft a metal to be used for swords and cutting instruments, but copper ores frequently contain associated metals, as, for example, tin, which would confer upon the copper the necessary hardness to enable it to be fashioned into weapons. Such copper would be of the character of bronze, and it was known to the early workers that the nature of the metal was greatly modified by the selection of ores from particular localities. It was comparatively late in the metallurgical history of copper that bronze was produced by knowingly adding tin to the metal.
Copper was largely used by the Romans, who obtained it from Cyprus; it was known to them as œs Cyprium, and eventually Cuprum, whence we obtain the chemical symbol Cu. What the Romans called œs was found also at Chalkis, in Eubœa, whence χαλκός, the Greek word for copper.
Aurichalcum, or golden copper—that is, brass—was well known to the early workers in copper, and was made in Pliny’s time by heating together copper, cadmia (calamine), and charcoal.
Bell metal was employed by the Assyrians, and bronze was cast by the Egyptians for the manufacture of mirrors, vases, shields, etc., as far back as 2000 B.C. Statuary bronze, largely used by the Romans, usually contained more or less lead.
Tin, which was also known to the early Egyptians, would appear to have been first obtained from the East Indies, and to have been known under the Sanscrit name of Kasiîra (Kâs, to shine), whence we have the Arabic word for tin, Kàsdir, and the Greek κασσίτερος, used by Homer and Hesiod. Tin ores are found in Britain (Cornwall), and were brought thence by the Phœnicians. The group of islands, including the Scilly Islands and the larger island to the east (Britain), was known to the Romans as the Insulœ Cassiterides.
Pliny states that the tin is found in grains in alluvial soil, from which it is obtained by washing; but he gives no description of the method of smelting. The Latin word for tin was stannum; it was also known as plumbum album, in contradistinction to lead, which was called plumbum nigrum. Tin was used by the Romans for covering the inside of copper vessels, and was also occasionally employed in the construction of mirrors.
Lead was well known to the Egyptians. In Pliny's time it was mainly procured from Spain and from Britain (Derbyshire). Leaden pipes were used by the Romans for the conveyance of water, and sheet lead was employed by them for roofing purposes. The Romans were also aware of alloys of lead and tin. Argentarium was composed of equal parts of lead and tin; tertiarium, used as a solder, consisted of two parts of lead and one part of tin.
Iron, although now the most important of the common metals, was not in general use until long after the discovery of gold, silver, and copper. This was probably due to the fact that, although its ores are relatively abundant and widely distributed, extraction as a metal demanded greater skill and more appliances than were possessed by the earlier races. Metallic iron was, however, well known to the Egyptians, who employed it in the manufacture of swords, knives, axes, and stone-chisels, both as malleable iron and as steel. Steel was also known to the Chinese as far back as 2220 B.C., and they were acquainted with the methods of tempering it. The good quality of Chinese steel caused it to be highly prized by Western nations. The earliest people to smelt iron are supposed to have been the Chalybes, a nation inhabiting the neighbourhood of the Black Sea; it is from them that the ancient name for steel—chalybs—is derived, and also our word “chalybeate.”
Mercury has long been known, but there is no evidence that the ancient Egyptians were aware of its existence, or it would probably have been mentioned by Herodotus. It was familiar to Aristotle, and its mode of manufacture from cinnabar is described by Theophrastus (320 B.C.), who terms it “liquid silver.” Processes of amalgamation were known to Pliny, who notes the readiness with which mercury dissolves gold. Pliny appears to distinguish the native metal found in Spain, which he terms argentum vivum (quicksilver), from that obtained by sublimation or distillation from cinnabar, which he calls hydrargyrum, from which we get the chemical symbol for mercury Hg.
A considerable number of metallic compounds were known to the ancients, and were employed by them as medicines and as pigments. The oxides of copper, known as flos œris, and scoria œris, obtained by heating copper bars to redness and exposing them to air, were used as escharotics. Verdigris, or œrugo, was made by the same methods as now. Blue vitriol, or chalcantum, is described by Pliny, who says that the blue transparent crystals are formed on strings suspended in its solution.
Chrysocolla, malachite, or copper carbonate, was used as a green pigment. The blue κύανος of the Greeks, or cœruleum of the Romans, was obtained by fritting together alkali, sand, and oxide of copper. Botryitis, placitis, onychitis, ostracitis, were varieties of cadmia or oxide of zinc, obtained by calcining calamine, and were used in the treatment of ulcers, etc. Molybdena, which was the Latin name for litharge, was employed externally as an astringent and in the manufacture of plaster. The lead plaster employed by Roman surgeons was practically identical in character and mode of preparation with that in use to-day. Cerussa, or white lead, was made as now by exposing sheets of lead to the fumes of vinegar. It was used in medicine, as a pigment, and in the preparation of cosmetics. Cerussa usia was probably red lead. Its present name of minium was originally applied to cinnabar, the red sulphide of mercury, which was frequently adulterated with red lead.
Cinnabar, formerly obtained from Africa, and, by the Romans, from Spain, was also used externally in medicine, and was a highly prized pigment, whose value was known to the Chinese from very early times. The black sulphide of antimony, the stimmi and stibium of Dioscorides and Pliny, was employed by women in Asia, Greece, and latterly in Western Europe, and is still so used in the East, for blackening their eyelashes. Preparations of antimony were used in medicine. Realgar, the scarlet sulphide of arsenic, the sandarach of Aristotle, and the arrenichon of Theophrastus, was employed as a pigment, and also in medicine, both internally and externally. The yellow sulphide of arsenic or auri pigmentum (orpiment), was also used for the same purposes.
A variety of yellow and red ochres, in addition to the pigments above mentioned, were used by painters, such as rubrica, an iron ochre of a dark red colour, and sinopis, or reddle, obtained from Egypt, Lemnos, and the Balearic Isles. Oxides of manganese were used as brown pigments. The white pigment, paratonium, was probably meerschaum. Melinum was a variety of chalk found in Samos. The ancients were well acquainted with indigo and madder, and with the method of manufacturing lakes, which was employed by Grecian artists.
The famous purpurissum was chalk or clay stained by immersion in a solution of Tyrian purple. Atramentum was lamp-black; ivory-black was used by Apelles, and was known as elephantinum. The ink of the ancients consisted of lamp-black suspended in a solution of gum or glue. The atramentum indicum, imported from the East, was indentical with China ink.
The ancients were well skilled in the art of dyeing, and even of calico printing. The Tyrians produced their famous purple dye as far back as 1500 B.C. It was obtained from shell-fish, mainly species of Murex, inhabiting the Mediterranean. Tyrian purple has been shown to be dibrom-indigo, and to have been produced by the action of air and light upon the juices exuded from the shell-fish. The fine linen of the Old Testament was probably cotton, for the production of which Egypt was long celebrated. That the Egyptians were acquainted with the use of mordants seems evident from the following passage from Pliny, quoted by Thomson:—
There exists in Egypt a wonderful method of dyeing. The white cloth is stained in various places, not with dye stuffs, but with substances which have the property of absorbing colours; these applications are not visible upon the cloth, but when they are dipped into a hot caldron of the dye they are drawn out an instant after dyed. The remarkable circumstance is that, though there be only one dye in the vat, yet different colours appear upon the cloth; nor can the colour be afterwards removed.
This passage accurately describes the process of madder dyeing on cotton, whereby a variety of fast colours—reds, browns and purples—can be obtained from same vat by the employment of different mordants, such as alumina, oxide of iron, or oxide of tin, etc.
Glass has been known from very early times. Representations of glass-blowing were found on the monuments of Thebes and Beni Hassan, and large quantities of glass were exported to Greece and Rome from Egypt, mainly by Phœnicians. Aristophanes mentions it as hyalos, and speaks of it as the beautiful transparent stone used for kindling fire. The Egyptians made use of various metallic oxides in colouring glass. The hœmatinon of Pliny was a red glass coloured with cuprous oxide. Cupric oxide was used to colour glass green; and ancient blue glass has been found to contain cobalt. The costly vasa murrhina of the Romans, obtained from Egypt, probably consisted of fluorspar, identical with the Blue John of the Derbyshire mines.
Stoneware has been made from time immemorial, and the Chinese have manufactured porcelain from very remote periods. Bricks and tiles were made by the Romans, and mortar and stucco were employed by the ancient Egyptians.
Soap (sapo) is mentioned by Pliny, but its detergent properties were apparently unknown to him. It appears to have been first made by the Gauls, who prepared it from the ashes of the beech and the fat of goats, and used it as a pomatum, as did the jeunesse d’oreé of Rome. Wood ashes, as well as natron, were, however, used by the ancients for their cleansing properties.
Starch, acetic acid, sulphur, alumen or crude sulphate of alumina, beeswax, camphor, bitumen, naphtha, asphalt, nitrum (carbonate of soda), common salt, and lime, were all known to the Egyptians, and were used by them for many of the purposes in which they are employed to-day.
It will be evident from this brief survey that the ancients possessed a considerable acquaintance with many operations of technical chemistry; but, although they must necessarily have accumulated a large amount of knowledge, very little has come down to us concerning the mode in which their processes were conducted, or as to the precautions they employed to ensure uniform results. Their methods were probably jealously guarded and handed down by successive members of the crafts as precious secrets. The experienced masters of these crafts must have met with many strange and perplexing phenomena in the course of their operations, and a spirit of inquiry must thereby at times have been awakened. But, under the conditions in which their industries were prosecuted, the scientific spirit was not free to develop, for science depends essentially upon free intercommunication of facts and the spread of knowledge of natural phenomena. Moreover, the great intellects of antiquity, for the most part, had little sympathy with the operations of artisans, who, at least among the Greeks and Romans, were, for the most part, slaves. Philosophers taught that industrial work tended to lower the standard of thought. The priests, in most ages, have looked more or less askance at attempts, on the part of the laity, to inquire too closely into the causes of natural phenomena. The investigation of nature in early times was impossible for religious reasons. There was an outcry in Athens when the thunderbolts of Zeus were ascribed to the collision of clouds. Anaxagoras, Diogenes of Apollonia, Plato, Aristotle, Diagoras, and Protagoras were charged by the priests with blasphemy and driven into exile. Prodikos, who deified the natural forces, as did Empedokles the primal elements, was executed for impiety. Sacerdotalism in Athens had no more sympathy with science than had the Holy Congregation in Italy when it banned the writings of Copernicus, Kepler, and Galileo, and sent Giordano Bruno to the stake. The educated Greeks had no interest in observing or in explaining the phenomena of technical processes. However prone they might be to speculation, they had no inclination to experiment or to engage in the patient accumulation of the knowledge of physical facts. “You Greeks,” says Plato in one of his Dialogues, “are ever children, having no knowledge of antiquity, nor antiquity of knowledge!” The influence of a spurious Aristotelianism, which lasted through many centuries and even beyond the time of Boyle, was wholly opposed to the true methods of science, and it was only when philosophy had shaken itself free from scholasticism that chemistry, as a science, was able to develop.