Pathfinders
Page 10
So what of the contents of the Corpus itself, or at least those parts of it that we can be confident were written by Jābir himself? He is known to have developed and perfected numerous chemical techniques, such as crystallization, distillation, evaporation, calcination (the thermal treatment of ores and minerals to separate out certain substances from them) and sublimation (the process by which a solid is heated directly to a vapour, then collected as sediment), all of which are standard fare in any chemical laboratory today. We also have him to thank for introducing the word ‘alkali’ into our vocabulary, a term which originates from the Arabic al-qāli, meaning ‘from ashes’ (because one of the most important alkali metals, potassium, came from the ashes of fires, which are mostly potassium carbonate). His use of sal ammoniac (as described in his Sandūk al-Hikma, The Chest of Wisdom) is also noteworthy because it is here that we first see the beginnings of the use of applied organic chemistry.
Jābir used his chemical knowledge in a number of practical processes, such as the prevention of rusting, the use of manganese dioxide in glass-making and the tanning of leather. Many of his descriptions are of industrial processes, such as furnaces for distillation, producing coloured glass, smelting and refining metals, as well as techniques for glazing ceramic tiles, preparing steel, and making dyes and varnishes. He also developed apparatuses like alembics (which, as you might guess from the first two letters, comes from the Arabic al-inbīq, itself derived from the Greek ambix, meaning ‘cup’). It is a vessel with a beaked cap that is part of the apparatus used in distilling. Its modern descendant is the pot still (which is used for distilling whisky).
Other new industrial processes, such as those associated with book-making (paper, inks and glues), as well as perfumes and pharmaceuticals, also grew around this time. All this activity points to a bustling economy demanding innovation and new technologies. Some of this industrialization would have also been seen in earlier civilizations from the Roman Empire to China, but it is no coincidence that many of the chemical words in use today derive from the Arabic: alcohol, alkali, alembic, amalgam, benzoic, borax, camphor, elixir and realgar. Of course, several of these words can be traced further back, to Greek, Persian or Indian origins.
A great example of applied chemistry was the manufacture of soap. Solid bars were barely known in northern Europe until the thirteenth century when they began to be imported from Islamic Spain and North Africa. By that time soap-making in the Islamic world had been industrialized: the town of Fez in Spain had some twenty-seven soap-makers, while cities like Nablus, Damascus and Aleppo became famous for the quality of their soaps.
I am referring of course only to solid soap bars and not suggesting that the Arabs invented soap itself. The use of substances as detergent goes back to the ancient Babylonians, who used boiled animal fats, wood ashes, even stale urine, which contains ammonia. The Greeks and Romans, too, used a form of soap, and Galen even records a recipe for boiling animal fats, oils and caustic soda.17 But it is the industrialization of the manufacture of soap bars that is new. This was at a time when Europe had descended into the filth and grime of its Dark Ages, during which cleanliness was not high on the agenda; in the Muslim world it was a religious requirement.
The chemists’ understanding of the properties of alkalis and other chemicals gave the glass-making industry a lift, too. They discovered that the colour of glass could be changed using new chemicals like manganese and newly discovered metallic oxides, and with their industrial furnaces, some several storeys high, they were able to manufacture coloured glass in huge quantities. The use of new pigments within ceramic tiles allowed them to decorate mosques in a glorious range of colours and designs.
What all the medieval Arabic texts on chemistry have in common is great attention to detail based on careful experimentation. The techniques that were developed drove a thriving and successful industry, but we also see in the work of Jābir the beginning of chemistry as an empirical science motivated by a desire to understand how the world is made up.
The periodic table one finds on the wall of every school science laboratory was conceived by the Russian chemist Dmitri Mendeleev in 1869. Its key idea is to group together substances with similar properties, as well as arranging them according to their atomic weight. On one side, for instance, are the inert gases and, on the other, the volatile metals. It is a triumph of classification, giving scientists a way of organizing their knowledge of the material world, something mankind has been striving to do since the dawn of time. But the very earliest attempts at this classification go back much further than is commonly assumed, and can be traced all the way back to medieval times and chemists such as Jābir.
When we develop ideas about how the natural world behaves we try to give it a kind of schema allowing us to organize its ingredients into categories so that we can make more sense of it, and this can in turn lead to further insights. The Greeks’ belief in the four fundamental elements of air, earth, fire and water was a purely philosophical idea with little practical value. Chemists in the Islamic Empire changed that, for they were the first to use experimental observations to classify the substances they knew.
Unlike later chemists, Jābir ibn Hayyān was still very much wedded to the same mystical and metaphysical mindset of his ancient Greek predecessors. He too believed that matter was ultimately composed of the four ‘natures’ or ‘primary’ characteristics of hot, cold, moist and dry, described by Aristotle. But the process of combining such abstract theories with experimentation was beginning to take form in his work. While still somewhat controversial, he is credited with the discovery of many chemical compounds, such as sulphuric acid – also known as vitriol – and hydrochloric acid (by mixing vitriol with salt). The scepticism of many historians over this particular claim is due to their assertion that the earliest known written recipes for these acids date from only the thirteenth century, particularly in the writings attributed to Pseudo-Geber.18 But we know, for instance, that the first clear instructions for the preparation of nitric acid can be found in Jābir’s treatise The Chest of Wisdom.19 There is also strong evidence20 that he was the first to make aqua regia, a mix of nitric and hydrochloric acids that dissolved gold – and therefore a vital solution for alchemists in their search for the philosopher’s stone. The discovery of inorganic acids such as these was hugely important in the development of chemistry.
Before I end this chapter, it is useful to say something about the man to whom Jābir passed the chemical baton; for the other great figure in medieval Islamic chemistry was Abū Bakr Muhammad ibn Zakariyya al-Rāzi (c. 854–c. 925). Known in the West as Rhazes, he was to become far more famous for his work in medicine and is regarded as the greatest physician of the medieval world. In chemistry, he extended and built on the work of Jābir and established the subject more firmly as a true experimental science based on careful and accurate observation.
One of al-Rāzi’s greatest achievements in chemistry was his classification scheme, which illustrated a level of sophistication far beyond that of Jābir. In his Book of Secrets (Kitab al-Asrār), written around the year 900 and essentially a treatise of alchemical secrets, he classified all substances into four groups: animal, vegetable, mineral and derivatives of these three. His minerals were in turn tabulated into six categories according to their chemical properties rather than superficial appearance, the same guiding principle that lies behind the modern periodic table. They were: spirits (such as quicksilver and sulphur), metals, stones, atriments, boraces and salts. Each group had a chemical property profoundly different from all the others: spirits were flammable, metals were shiny and malleable, salts dissolved in water, and so on. While these classifications are not the way we organize chemicals today, the point is that, for the first time, al-Rāzi was grouping substances on the basis of experimental observations, not philosophical musings.
So to those who still suggest that chemistry did not truly come of age until Renaissance Europeans such as Robert Boyle (1627–91) and Ant
oine Lavoisier (1743–94), I would argue that their definition of chemistry as a proper experimental science is too rigid. Of course the Islamic chemists were way off beam with many of their theories. But science does not begin with the latest, most accurate, theories. For how then should we treat Newton’s law of gravitation? We now know it to be based on the erroneous belief that the gravitational force acts instantaneously between bodies, however far apart they are. This magical ‘action at a distance’ was replaced by the more accurate description of gravity as a curvature of space-time in Einstein’s General Theory of Relativity. But no one claims that Newton’s work on gravity is not science. Indeed, it is rightly considered as one of the very greatest scientific discoveries in history.
At the opposite extreme, we can all agree that the alchemical magic and spells of the ancients are not part of science. The question is where we draw the line in the work of Jābir ibn Hayyān. This is where we appeal to the quite clear definition of the scientific method: it is the investigation of phenomena, acquiring of new knowledge, and correcting and integrating previous knowledge, based on the gathering of data through observation and measurement. Wherever it is being practised, that is where real science is being done. So was Jābir doing real science? Not quite. Some of the ingredients of the scientific method were not yet in place. But I am more than happy to refer to him as a scientist. What is more, he was the very first of the great scientists of the golden age, even though he did not live to see the creation of al-Ma’mūn’s great academy in Baghdad, the place where we see the golden age truly beginning. It was known as the House of Wisdom and its light would radiate across the empire, and beyond.
5
The House of Wisdom
The teacher who is indeed wise does not bid you to enter the house of his wisdom but rather leads you to the threshold of your mind.
Khalil Gibrān
Court astrologers, physicians, engineers, architects and mathematicians have played an important role in many societies going back millennia before the Abbāsids, serving the practical needs of government, whether it was casting horoscopes, treating the sick, designing temples, palaces, bridges and canals, developing ever more sophisticated weapons, or devising new and easier methods for calculating taxes or dividing estates. But with the arrival of Islam, new responsibilities began to appear. For instance, astronomers and mathematicians were required to determine the times of prayer and the direction of Mecca, and to track the phases of the moon, all of which required increasingly sophisticated and advanced scientific know-how.
It was only during al-Ma’mūn’s reign, however, that a huge and sudden shift in emphasis took place, from the purely practical employment of these men of learning (’ulamā’) to a culture that encouraged free and creative thinking across a wide range of disciplines.
Whether or not al-Ma’mūn dreamt of Aristotle while still in Merv, he was certainly inspired enough to initiate regular discussion sessions and seminars among experts in kalām, the art of philosophical debate – a custom he had learnt from his Persian tutor Ja’far. He would invite religious experts and literary scholars to his palace from far and wide to present their ideas to him in an open intellectual atmosphere. Following his triumphant return to Baghdad in 819, this custom continued and grew. He offered lucrative financial incentives and generous hospitality to a wide range of scholars. Every week, guests were invited to the palace, wined and dined, and then would begin to discuss with the caliph all manner of scholarly subjects, from theology to mathematics.1
Al-Ma’mūn was not satisfied with simply listening to what these learned men had to say. He was well aware of the treasures to be found in the ancient texts of the Greek philosophers, some of which had already begun to be translated for the Abbāsid caliphs before him. He would send emissaries great distances to get hold of these scientific texts. Often, foreign rulers defeated in battle would be required to settle the terms of surrender to him with books from their libraries rather than in gold. Al-Ma’mūn was almost fanatical in his desire to collect all the world’s books under one roof, translate them into Arabic and have his scholars study them. The institution he created to realize his dream epitomizes more than anything else the blossoming of the scientific golden age. It became known throughout the world as the House of Wisdom (Bayt al-Hikma). Or so the story goes.
Before we look at the activities and main characters in al-Ma’mūn’s Baghdad, I should make clear from the outset that no physical trace remains of the House of Wisdom today so we cannot be sure where it was located or what it looked like, or the range of activities carried out there. In fact, some historians argue against exaggerated claims about its scope and purpose and the role of al-Ma’mūn in setting it up.2 They warn against the ‘fanciful and sometimes wishful projections of modern institutions and research projects back into the ninth century’;3 and argue that the House of Wisdom was nothing like as grand as it became in the eyes of many once the activities of the scholars in al-Ma’mūn’s court had become the stuff of legend. This, they believe, is the only reliable way of interpreting what little we have to go on from the historical records left to us.
Many also make the quite legitimate point that to focus on one, possibly mythical, institution detracts from the sheer scale of original scholarship that was carried out all over al-Ma’mūn’s Baghdad, for there would probably have been hundreds of private libraries around the city. So rather than trying to collect up many diverse activities under one roof, we should really be talking about the whole of Baghdad as the Medinat al-Hikma (‘City of Wisdom’).
However, this over-caution smacks a little of babies and bathwater, for the absence of evidence should not be too hastily interpreted as evidence of absence. We should certainly therefore examine the subject more carefully. Perhaps the House of Wisdom was indeed no grander than a palace library, modelled on older Persian libraries. So why should we regard it as being any more special than these other, earlier libraries?
The notion of a repository of written records goes back long before Islam. Probably the most famous of the ancient world was the great Library of Alexandria, but few records survive as to the size and layout of this academy either. It is known to have contained many thousands of ‘books’, each comprising several papyrus scrolls. Like al-Ma’mūn’s House of Wisdom, the legacy of the Library of Alexandria has reached mythical proportions, the most famous concerning its ultimate fate. One story is that it was destroyed in a fire in 48 BCE by Julius Caesar’s army; that this took place during his occupation of Alexandria while ‘resolving’ the civil war in Egypt between King Ptolemy XIII and his sister Cleopatra. Another, because there are extant records of the library from much later, is that it survived well into the late third century CE, when it was destroyed in another war over the control of Egypt between the Roman Emperor Aurelian and the great Syrian Queen Zenobia, who ruled over Egypt at the time. There is even a mythical account of the library being sacked by the Arabs after their conquest of Alexandria in 641 under the Caliph Omar. Most likely of all, however, is that it was destroyed in the late fourth century by Alexandrian Christian followers of the Coptic Pope Theophilus in a revolt against the pagans of the city and for whom the library was a powerful symbol of Greek pagan teaching.
I recently visited the new Bibliotheca Alexandrina, built on the original site of the old library and completed in 2002. This huge and hugely impressive modern architectural edifice is today a cultural centre containing manuscript archives, museums, art exhibitions, even a planetarium. Visitors are struck by the sheer scale of the building, with its vast, well-lit open halls, but it still has a long way to go to fill its shelves with the eight million books there is space for.
The first systematically organized library in the world, much older than the one in Alexandria, had flourished in northern Iraq. The great Assyrian library of Nineveh was built by King Ashurbanipal (r. 668–627 BCE), and contained more than twenty thousand clay tablets with cuneiform texts. Just as in Alexandria, this remarkable
library was destroyed by fire, but an advantage of clay over papyrus, parchment or paper is of course that it is immune to flames and the tablets were simply baked hard. So we have available a huge body of information from that library about the life not only of the Assyrians, but of the Babylonians before them whose culture they inherited.
The origin of Islamic libraries actually goes back to the Umayyad Caliph Mu’awiya (r. 661–80) in Damascus, who housed a collection of books in what has also been referred to as a Bayt al-Hikma.4 So libraries were not new concepts to the Abbāsids. There is also little doubt that their early libraries were modelled on those of Damascus as well as on Persian libraries in cities such as Isfahan and Gondēshāpūr. Since the Abbāsid dynasty was built through a fusion of Arabic and Islamic administration and Zoroastrian and Sasanian culture, the Persian influence is seen everywhere: copying the Sasanians’ model of a library was only natural.