James Richard Fromm
Greek manuscripts, including all of the writings of Aristotle, were widely distributed throughout the Greek and Roman world. Alexandria, founded by Alexander of Macedon in BC 331, became under the Ptolemies and early Roman Empire a center of learning. Its Library and Museum were the largest collection of scrolls and books in the world and its scholars were active. Among the Alexandrian writings are some which include practical and mystical chemistry, which became known as the "Egyptian art", or chemeia, after the name of the black soil of Egypt. Some of them are attributed to Hermes Trismegistos (thrice greatest Hermes, a mythical figure perhaps based on the Egyptian god Thoth) and the writings became known as Hermetic writings.
Since the writings of chemeia included ways to change the colors of metals, Emperor Diocletian suspected counterfeiting and ordered them banned in AD 296- an inauspicious beginning for chemistry. After Christianity became lawful under Constantine (Emperor AD 324 - 337), all classical teachings were looked upon with less favor. In AD 389 the Library of Alexandria was destroyed by fire and the Museum was closed, and in AD 415 the Museum also burned. The scholarly tradition was maintained in Alexandria, however, while elsewhere it declined - Plato's Academy of Athens was closed in AD 529 by order of Emperor Justinian. When Egypt was taken over in AD 641 by the Arabs much of classical knowledge passed into the Islamic culture. Thus, often through the medium of heretical Greek Christians unwelcome in the Byzantine Empire, the ideas of chemeia reached the Arab world and were taken over by it as al-chemeia or alchemy. While ancient learning declined and was in large part lost with the Christianizing, and later the fall, of the Roman Empire, some was preserved both in the Western Christian monastic communities and in the Arabic culture which followed the rise of Islam in the Near East.
The Christian contributions to science come in two phases, which we may call Monastic Preservation (AD 400 --1100) and Encyclopedic Scholasticism (AD 1100 - 1300). The Arabic contribution (AD 800 - 1100) spans these two Christian phases. Christian monastic communities began to form in about AD 400, and soon after began to make copies of sacred manuscripts. Many Greek manuscripts on all subjects survived to come to us only by being copied along with the sacred Christian text of the Scriptures. This was essentially the only contribution to chemistry of the early Christian monastics. After AD 1100, the monastic orders, which in the West then had a virtual monopoly on education, reading, and writing, were strengthened by new foundations such as the Franciscans (AD 1210) and the Dominicans (AD 1215). A great deal of work is done on the systematization and encyclopedic compilation of knowledge and thought, both theological and otherwise. The height of scholasticism, around AD 1250, is probably St. Thomas Aquinas (AD 1225 - 1274), whose Summa Theologica is still a most valuable work. Aquinas, like his predecessor Albert von Bollstaedt (Albertus Magnus, AD 1193 - ?) was a Dominican. The English scientific philosopher Roger Bacon (AD 1214 - 1294) was a Franciscan.
Some chemical thinking, although not much, was included in these compilations and analyses. This monastic monopoly on knowledge really did not end until the invention of printing (J. Gutenberg, AD 1400? - 1467), although it began to dwindle much earlier. Up to AD 1200, for example, virtually no technical manuscripts are known, while their number rapidly increases from AD 1200 through AD 1500.
Encyclopedic scholasticism was strongly systematic and attempted to organize all knowledge, theological or not, into a common general framework. The framework was based firmly upon Aristotle.
The four elements of Aristotle make up the four central spheres of fire, air, water, and earth. The fifth element of Aristotle, the ether, makes up the outer reaches or heavens, of which there are seven. These are the heavens of the moon and planets, ranging outward from that of the moon through the sun and the known planets (Mercury, Venus, Mars, Jupiter, Saturn), followed by that of the fixed stars. Beyond that is the realm of the Heavens, or of God and the angels represented in various ways. Thus the systematic work of Aristotle, incorporated in the equally systematic dogmatic theology of the Middle Ages, became a fixed pattern. Since the elements of Aristotle were not subject to experiment because they were ideal cases, the challenge to this integration came from the heavens of astronomy rather than the more earthly field of chemistry.
The Arabic contributions to chemistry came after the rise of Islam in the Near East, which began about AD 600. They lasted through the Islamic empires there, and flourished from about AD 900 - 1200. Much of this development took place in the area of medicine and medicinal chemistry. By AD 780, Muslim coiners could, and did, use balances to weigh to within 0.0003 gram (0.3 mg). However, the application of such precise measurement devices was restricted to coins and medicinal dosages and did not include fundamental chemical experiments.
The chemically significant Arab writers were all medical doctors. Classical Greek medical knowledge, first clarified by Hippocrates and his followers, had been set down by Galen (AD 129 - 199). Galen's doctrine of the four humors of the body is very similar to Aristotle's presentation of the four elements, and the colors of the humors - the red of blood, the yellow of bile, the black of black bile, and the white of phlegm - would be later in medieval alchemy associated with the four elements. The first of the Arab physicians, Jabir ibn Hayyan (AD 790? - 813), became known in the West as Geber. Little is known of Geber's actual writings although many manuscripts dating from around AD 1300 are falsely attributed to him. This characteristic of attributing writings to well-known persons who were usually safely dead, common from at least AD 300 to AD 1300, has caused problems for historians and it is possible that Geber is a mythical figure. There is better evidence for the historical existence of al-Razi (AD 886 - 925), known in the West as Rhases, a skillful practical chemist although better known as a physician. The last and best-known was ibn Sina (AD 980 - 1036) of Persia, or modern Iran, whose writings (translated into Latin, as was his name: Avicenna) were used as a medical text long after AD 1000.
The Arab understanding of bodies, as metals were then referred to, came at least in part from Aristotle. Metals were considered to be composed of mercury and of sulfur, and were generated slowly in the earth from these basic materials. This idea is fundamentally a reasonable one, since most metals are found in the form of metal sulfides in nature. When these are heated, as is often done as the first or roasting step in the smelting process, the sulfur is driven off as SO2 and can easily be recognized as the same smell which arises from burning sulfur. Al-Razi composed a general classification of all substances, later used by alchemists; all substances were of animal, vegetable, or mineral origin. All other known materials were classified as derivatives of these three classes. Al-Razi listed several mineral materials: cinnabar, white lead, red lead, copper oxide, wine vinegar; perhaps also caustic soda (NaOH) and impure glycerine.
Al-Razi classified mineral substances into six categories. The first, the bodies, were the metals then known, with the exception of the liquid metal mercury, and were the same metals known to the ancient world. The second category, the stones, included ores and rocks; examples would be pyrites, malachite, gypsum, galena, and glass. The third category, the salts, were substances such as common salt (NaCl) and slaked lime (Ca(OH)2) which dissolved in water. The fourth category, the boraces, were the fusible solids which could be melted such as natron and borax
(Na2B4O7.10H2O). The fifth category, the vitriols, were the corrosive substances such as alum and iron (II) sulfate; this category led to our more modern concept of acids. The last category, the volatile materials or spirits, was further subdivided into the non-burning or incombustible spirits, which would include mercury (Hg) and sal ammoniac (ammonium chloride, NH4Cl), and the burnable or combustible spirits. Combustible spirits included sulfur (S) and 'arsenic'. The latter is probably not elemental arsenic, but one of its sulfides; either realgar, As2S2, an orange-red resinous substance used as a pigment, or orpiment, As2S3 or native arsenic trisulfide, a pearly material which is easily cut, used as a pigment and dyestuff.
Many of the words used by the Arabs in describing science have been retained and have entered the English language. The major contributions of the Islamic culture were in three areas of science: chemistry, mathematics, and astronomy. In chemistry, Arabic words include alcohol, alkali (from al-quali, the saltwork ashes), niter (from which word we get nitrate), alkahest (the universal solvent, sought by the alchemists), and alembic (a distilling flask). In mathematics, some of the Arabic terms are algorithm, algebra, and arithmetic. In astronomy, Arabic terms include almanac, zenith, nadir, and many of the names of the visible stars, such as Aldebaran, Algol, and Betelgeuse.