Читать книгу The Fontana History of Chemistry - William Brock J. - Страница 15

Philippus Aureolus Theophrastus Bombast von Hohenheim (1493–1541), who rechristened himself Paracelsus in order to indicate his superiority to the second-century Roman medical writer, Celsus, was born near Zurich, then still nominally part of the Holy Roman empire and under Austrian domination. At the age of twenty-one, on the advice of his physician father, he visited the mines and metallurgical workshops in the Tyrol where he studied metallurgy and alchemy. After claiming a medical degree from Ferrara in Italy, Paracelsus became Medical Officer of Health at Basel, a position he was forced to leave in an undignified manner two years later after his abusive and bombastic manner had offended public opinion. Thereafter, he became a rolling stone, restlessly traversing the roads and countries of war-torn Europe, associating with physicians, alchemists, astrologers, apothecaries, miners, gypsies and the adepts of the occult.

It is easy to see why he offended. Not only did he lecture in German instead of Latin, an unorthodox behaviour for a physician, but he publicly burned the works of Galen and Avicenna to show his contempt for orthodox medical opinion – a ceremony that was to be repeated by Lavoisier and his wife 250 years later.

If your physicians only knew that their prince Galen … was sticking in Hell, from whence he has sent letters to me, they would make the sign of the cross upon themselves with a fox’s tail. In the same way your Avicenna sits in the vestible of the infernal portal.

Come then and listen, impostors who prevail only by the authority of your high positions! After my death, my disciples will burst forth and drag you to the light, and shall expose your dirty drugs, wherewith up to this time you have compassed the death of princes .… Woe for your necks on the day of judgement! I know that the monarchy will be mine. Mine too will be the honour and the glory. Not that I praise myself: Nature praises me.

Is this rhetoric or the ravings of a lunatic?

Not surprisingly, contemporary estimates of Paracelsus varied tremendously. An opinion that ‘he lived like a pig, looked like a drover, found his greatest enjoyment in the company of the most dissolute and lowest rabble, and throughout his glorious life he was generally drunk’, may be contrasted with his pupils’ expressions, ‘the noble and beloved monarch’, ‘the German Hermes’ and ‘our dear Preceptor and King of Arts’. What did this contradictory, bewildering figure do for chemistry? What did he teach?

Most of his writings were only published posthumously and there has always been controversy between historians who accept only the ‘rational’ writings as genuine and those who view his eclectic mixture of rationalism, empiricism, Neoplatonic occultism and mysticism as the genuine Paracelsus. Although he definitely subscribed to alchemy, i.e. to the doctrine of transmutation, ‘alchemy’ had a wider meaning for Paracelsus. It entailed carrying ‘to its end something that [had] not yet been completed’. It was any process in Nature in which substances worked or metamorphosed to a new end, and thus included cookery and the chemical arts as well as physiological processes such as digestion.

This widened sense of the word was to be reflected explicitly in what has been described as the first chemistry textbook, the Alchemia published by the Lutheran humanist, Andreas Libavius (1540–1616), in 1597, though, as we shall see, Libavius was contemptuous of Paracelsus. For Paracelsus, chemistry was the key subject for unveiling the secrets of a universe that had been created by a chemist and operated by chemical laws. The views of Aristotle and Galen were those of heathens and heretics and had to be replaced by an empiricism that was controlled by Christian and Neoplatonic insights. Paracelsus and his followers, such as Ostwald Croll in his ‘royal chemistry’, the Basilica Chymica (1609), often made much of the story of creation in Genesis, which they interpreted as a chemical allegory. Paracelsianism thereby came to share many of the attributes of esoteric alchemy in which ‘the art’ was essentially a personal religious avocation.

On the other hand, Paracelsus saw himself essentially as a medical reformer, as someone destined to refute age-old teachings and to base medical practice on what he claimed were more effective mineral medicines. He taught that the principal aim of medicine should be the preparation of arcana, most of which turn out to be chemical, inorganic remedies as opposed to the herbal, organic medicines derived from Greco-Roman medicine. The arcana would destroy and eliminate poisons produced by disease, which itself was due to the putrefaction of the ‘excrements’ produced in any ‘chemical’ process. Diseases were therefore specific, as the new pandemic of syphilis then sweeping Europe suggested, and were to be cured by specific arcana.

Paracelsus taught that macrocosm (the heavens) and microcosm (the earth and all its creatures) were linked together. The heavens contained both visible and invisible stars (astra) that descended to impregnate the matter of the microcosm, conferring on each body the specific form and properties that directed its growth and development. Like acted upon like. The task of the chemist was, by experiment and knowledge of macrocosmic – microcosmic correspondences (the doctrine of signatures), to determine an astral essence or specific virtue capable of treating a disease. To isolate the remedy, the alchemist-physician had to separate the pure essence from the impure, by fire and distillation. Here, Paracelsus owed much to the medieval technology of distillers and to the writings of John of Rupescissa in the fourteenth century. The latter had identified Aristotle’s fifth, heavenly element, the ether, as a quintessence that could be distilled from plants. Paracelsus and his followers were, however, rather more interested in the inorganic salts remaining after distillation than in the distillates themselves.

In this way Paracelsus initiated a new study he called ‘iatrochemistry’, which invoked chemistry to the aid of medicine. Whereas the Paracelsians were individualistic in their pantheistic interpretation of Nature, regarding chemical knowledge as incommunicable except between and through the inspiration proper to a magus, Libavius and the textbook writers who followed him argued that chemistry could be learned by all in the classroom, provided it was put into a methodical form. This construction of a pedagogical discipline involved the classification of laboratory techniques and operations and the establishment of a standardized language of chemical substances. Progress in chemistry, or in any science, would come only from a collective endeavour to combine the subjective, and possibly unreliable, contributions of individuals after subjecting them to peer review and measuring each one critically against past wisdom and experience.

Iatrochemical doctrines became extremely popular during the seventeenth century, and not unlinked with this was a rise in the social status of the apothecary. Both in Britain and on the Continent there was a compromise in which chemical remedies were adopted without commitment to the Paracelsian cosmology. Didactically acquired knowledge of iatrochemistry gave these medical practitioners (who in Britain were to become the general practitioners of the nineteenth and twentieth century) a base upon which they could branch out into their own medical practice and away from the control of university-educated physicians. The need for self-advertisement encouraged them to teach iatrochemical practice and to introduce inorganic remedies into the pharmacopoeia. They were therefore less secretive than the alchemists. Because they wanted to find and prepare useful medical remedies, they were keen to know how to recognize and prepare definite chemical substances with repeatable properties. In teaching their subject, what was wanted was a good textbook, which would provide clear and simple recipes for the preparation of their drugs, with clear unambiguous names for their substances and adequate instructions on the making and use of apparatus for the preparations. Theory could play second fiddle to practice.

Iatrochemistry became very much a French art and here the subject was helped in Paris by the existence of chemical instruction at the Jardin du Roi. Beginning with Jean Beguin’s Tyrocinium Chymicum in 1610, which plagiarized a good deal from Libavius’ Alchemia, each successive professor, Étienne de Clave, Christopher Glaser and Nicholas Lemery, composed a textbook for the instruction of the apothecary’s apprentices who flocked to their annual lectures. Many of these texts went into other languages, including Latin and English. By 1675, when Lemery published his Cours de Chimie, a textbook tradition had been firmly established as part of didactic chemistry and which considerably aided the establishment of chemistry as a discipline. Some historians of chemistry believe that this formulation of chemistry as a scholarly, didactic discipline, which began with Libavius well before the establishment of the mechanical philosophy, was far more significant than the latter for the creation of modern chemistry.

In chemical theory, Paracelsus introduced the doctrine of the tria prima, or the three principles. Medical substances, he said, were ultimately composed from the four Aristotelian elements, which formed the receptacles or matrices for the universal qualities of a trinity of primary bodies he called salt (body), sulphur (soul) and mercury (spirit).

The world is as God created it. He founded this primordial body on the trinity of mercury, sulphur and salt and these are the three substances of which the complete body consists. For they form everything that lies in the four elements, they bear them all the forces and faculties of perishable things.

The doctrine of the tria prima was clearly an extension of the Arabic sulphur – mercury theory of metals applied to all materials whether metallic, non-metallic, animal or vegetable, and given body by the addition of a third principle, salt.

This theory of composition, which essentially explained gross properties by hypothetical property-bearing constituents, rapidly replaced the old sulphur – mercury theory, though not the Aristotelian four elements. Paracelsus was happy to use Aristotle’s example of the analysis of wood by destructive distillation to justify the tria prima theory. Smoke was the volatile portion, mercury; the light and glow of the fire demonstrated the presence of sulphur; and the incombustible, non-volatile ash remaining was the salt. Water was included within the mercury principle, which explained the cohesion of bodies.

Van Helmont begged to differ and provided a simpler, and supposedly more empirical, alternative theory of composition.