The Fontana History of Chemistry. William Brock J.

in the lid and percolated back onto the plants below. In a variation of this, no holes were drilled and the distillate was collected directly in the trough around the rim, from where it was probably removed from time to time by means of a dry cloth. In the Mongolian or Chinese still, the distillate fell from a concave roof into a central catch-bowl from which a side-tube led to the outside. Modern experiments, using working glass models of these stills, have shown that⁵:

      the preparation of strong spiritous liquor was, from a technological point of view, a rather simple matter and no civilisation had a distillation apparatus which gave it an advantage.

      Even so, although the Chinese probably had distilled alcohol from wine by the fourth century AD, it was several centuries later before it was known in the west. Even earlier, in the second century of our era, the Chinese had discovered how to concentrate alcohol by a freezing process, whereby separation was achieved by freezing water and leaving concentrated alcohol behind.

      The observation of distillation also provided a solution to the theoretical problem of what made solid materials cohere. The binding material could not be Aristotelian water since this patently could not be extracted from a heated stone. Distillation of other materials showed, however, that an ‘oily’ distillate commonly succeeded the ‘aqueous’ fraction that first boiled off at a lower temperature. It could be argued, therefore, that an ‘unctuous’, or fatty, moisture was the cohesive binder of solid bodies. This notion that ‘earths’ contained a fatty material was still to be found in Stahl’s theory of phlogiston in the eighteenth century.

      An improvement on distillation techniques was apparently first made by Alexandrian alchemists in the first century AD – though, in the absence of recorded evidence, it is just as likely that these alchemists were merely adopting techniques and apparatus from craftsmen and pharmacists. This is particularly evident in the ‘kerotakis’, which took its name from the palette used by painters and artists. This wedge-shaped palette was fitted into an ambix (still-head) as a shelf to contain a substance that was to be reacted with a boiling liquid, which would condense, drip or sublime onto it. These alchemists made air cooling in the distillation process more efficient by separating the distillate off by a continuous process and raising the ambix well above the bikos or cucurbit vessel embedded in the furnace or sand bath. (In 1937 the word Ambix was adopted by the Society for the History of Alchemy and Early Chemistry as the title of the journal that ever since has played an important role in the history of chemistry.) In the Latin west the word alembic (from the Arabic form of ambix, ‘al-anbiq’) came to denote the complete distillation apparatus. By its means, rose waters, other perfumes and, most importantly, mineral acids and alcohol began to be prepared and explored in the thirteenth century.

      Continuous distillations were also made possible in the ‘pelican’, so-called because of its arms, which bore resemblance to that bird’s wings. Such distillations were believed to be significant by alchemists, who were much influenced by Jābir’s reputed success at ‘projection’ (the preparation of gold) after 700 distillations. The more efficient cooling of a distillate outside the still-head appears to have been a European contribution developed in the twelfth century. Alchemists and technologists referred to these as water-cooled stills or ‘serpents’. This more efficient cooling of the distillate probably had something to do with the preparation of alcohol in the twelfth century, some centuries after the Chinese. This became an important solvent as well as beverage in pharmacy. By then chemical apparatus was becoming commonly made of glass. It should be noted that, although ‘alcohol’ is an Arabic word, it had first meant antimony sulphide, ‘kohl’. In the Latin west, alcohol was initially called ‘aqua vitae’ or ‘aqua ardens’ (the water that burns), and only in the sixteenth century was it renamed alcohol. It had also been named the ‘quintessence’, or fifth essence, by the fourteenth-century Spanish Franciscan preacher, John of Rupescissa, in an influential tract, De consideratione quintae essentiae. According to John, alcohol, the product of the distillation of wines, possessed great healing powers from the fact that it was the essence of the heavens. An even more powerful medicine was obtained when the sun, gold, was dissolved in it to produce ‘potable gold’. John’s advocation of the quintessence was extremely important since it encouraged pharmacists to try and extract other quintessences from herbs and minerals, and thus to usher in the age of iatrochemistry in the sixteenth century. Here was the parting of the ways of alchemy and chemistry.

      The sixteenth century saw great improvements in chemical technology and the appearance of several printed books dealing with the subject. Such treatises mentioned very little chemical theory. They aimed not to advance knowledge, but to record a technological complex that, in Multhauf’s opinion, ‘although sophisticated, had been virtually static throughout the Christian era’. Generally speaking they discussed only apparatus and reagents, and provided recipes that used distillation methods. Many recipes, especially those for artists’ pigments and dyes, bear an astonishing resemblance to those found in the aurifictive papyri of the third century and therefore imply continuity in craftsmen’s recipes for making imitation jewellery, textile dyeing, inks, paints and cheap, but impressive, chemical ‘tricks’.

      One such book was the Pirotechnia of Vannoccio Biringuccio (1480–1538), which was published in Italy in 1540. This gave a detailed survey of contemporary metallurgy, the manufacture of weapons and the use of water-power-driven machinery. For the first time there was an explicit stress upon the value of assaying as a guide to the scaling up of operations and the regular reporting of quantitative measurements in the various recipes. On alchemy, despite retaining the traditional view that metals grew inside the earth, Biringuccio provides a sceptical view based upon personal observation and experience⁶:

      Now in having spoken and in speaking thus I have no thought of wishing to detract from or decrease the virtues of this art, if it has any, but I have only given my opinion, based on the facts of the matter. I could still discourse concerning the art of transmutation, or alchemy as it is called, yet neither through my own efforts nor those of others (although I have sought with great diligence) have I ever had the fortune to see anything worthy of being approved by good men, or that it was not necessary to abandon as imperfect for one cause or another even before it was half finished. For this reason I surely deserve to be excused, all the more because I know that I am drawn by more powerful reasons, or, perhaps by natural inclination, to follow the path of mining more willingly than alchemy, even though mining is a harder task, both physical and mental, is more expensive, and promises less at first sight and in words than does alchemy; and it has as its scope the observation of Nature’s powers rather than those of art – or indeed of seeing what really exists rather than what one thinks exists.

      That is succinctly put: by the sixteenth century, the natural ores of metals, and their separations and transformations by heat, acids and distillations, had become more interesting and financially fruitful than time spent fruitlessly on speculative transmutations.

      Alchemy had been transmuted into chemistry, as the change of name reflected. Here a digression into the origins of the word ‘chemistry’ seems appropriate. There is, in fact, no scholarly consensus over the origins of the Greek word ‘chemeia’ or ‘chymia’. One familiar suggestion has been a derivation of the Coptic word ‘Khem’, meaning the black land (Egypt), and etymological transfer to the blackening processes in dyeing, metallurgy and pharmacy. What is certain is that philosophers such as Plato and Aristotle had no word for chemistry, for the term ‘chymia’, meaning to fuse or cast a metal, dates only from about 300 AD. A Chinese origin from the word ‘Kim-Iya’, meaning ‘gold-making juice’, has not been authenticated, though Needham has plausibly suggested that the root ‘chem’ may be equivalent to the Chinese ‘chin’, as in the phrase for the art of transmutation, lien chin shu. The Cantonese pronunciation of this phrase would be, roughly, lin kem shut, i.e. with a hard ‘k’ sound. Needham concludes that we have the possibility that ‘the name for the Chinese “gold art”, crystallised in the syllable chin (kiem) spread over the length and breadth of the Old World, evoking first the Greek terms for chemistry and then, indirectly, the Arabic one’.

      Whatever the etymology, the Latin and