Abu Bakr Muhammad ibn Zakariyya al-Razi (866-925)
After his first visit to Baghdad, when he was at least 30 years of age, he seriously took up the study of medicine. Razi showed such skill in the subject that he quickly surpassed his teacher, and wrote no fewer than a hundred medical books. He also composed 33 treatises on natural science (exclusive of alchemy), on mathematics and astronomy, and more than 45 on philosophy, logic and theology. On alchemy, in addition to his Compendium of Twelve Treatises and the Book of Secrets, he wrote about a dozen other books, two of which were refutations of works by other authors in which the possibility of alchemy had been attacked.
Razi is of exceptional importance in the history of chemistry, since in his books we find for the first time a systematic classification of carefully observed and verified facts regarding chemical substances, reactions and apparatus, described in language almost entirely free from mysticism and ambiguity.
Razi's scheme of classification of the substances used in chemistry
shows it as the first systematic classification.
To these 'natural substances' we need to add a certain number of artificially obtained substances; al-Razl mentions litharge, lead oxide, verdigris, copper oxide, zinc oxide, cinnabar, caustic soda, a solution of polysulphur of calcium and other alloys.
The insistence of al-Razl in promoting research work in the laboratory brought its fruits in pharmacy.
Razi gives also a list of the apparatus used in chemistry. This consists of two classes:
(i) instruments used for melting metals, and
(ii) those used for the manipulation of substances generally.
It will be observed that the list was comprehensive, but Razi
completes the subject by giving details of making composite pieces of apparatus,
and in general provides the same kind of information as is to be found nowadays
in manuals of laboratory arts. Like Jabir, Razi was a firm believer in the
possibility of transmutation.
The first stage: consisted in the cleansing and purification of the substances employed, by means of distillation, calcination, amalgamation, sublimation and other processes. Having freed the crude materials from their impurities,
The next stage: was to reduce them to an easily fusible condition. This was done by an operation known as aeration, that resulted in a product which readily melted, without any evolution of fumes, when dropped upon a heated metal plate.
The third stage: was to bring the 'berated' products to a further state of disintegration by the process of solution. The solutions of different substances, suitably chosen in proportion to the amount of 'bodies' & 'spirits' they were supposed to possess, were brought together by the process of combination.
Finally: the combined solutions underwent the process of coagulation or solidification, the product which it was hoped would result, being the Elixir. This, as previously explained, was a substance of which a small quantity, when projected upon a larger quantity of baser metal, would convert the latter into silver or gold.Razi must be accepted as one of the most remarkable seekers after knowledge that the world has ever seen - not only 'unique in his age and unequaled in his time', but without a peer until modern science began to dawn in Europe with Galileo and Robert Boyle. The evidence of his passion for objective truth that is furnished by his chemical writings, as well as the genius shown by the wide range of books he wrote on other subjects, force us to the conclusion that - with the possible exception of his acknowledged master, Jabir - Razi was the most noteworthy intellectual follower of the Greek philosophers of the seventh to fourth centuries B.C. that mankind produced for 1900 years after the death of Aristotle. His supreme merit lay in his rejection of magical and astrological practices, and adherence to nothing that could not be proved, by experiment and test, to be actual fact.