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spirits, some impart dulness, and some, which were highly prized, that could secure a return of love? It had been long known that both natural and artificial waters can permanently affect the health, and that instruments may be made to ascertain their qualities. Zosimus, the Panopolitan, had described in former times the operation of distillation, by which water may be purified; the Arabs Chemical called the apparatus for conducting that experiment an alembic. His treatise on the virtues and composition of waters was conveyed under the form of a dream, in which there flit before us fantastically whitehaired priests sacrificing before the altar; cauldrons of boiling water, in which there are walking about men a span long; brazen-clad warriors in silence reading leaden books, and sphinxes with wings. In such incomprehensible fictions knowledge was purposely, and ignorance conveniently concealed.

waters.

The Arabs originate scientific

The practical Arabs had not long been engaged in these fascinating but wild pursuits, when results of very great importance began to appear. In a scientific point of view, the discovery of the strong chemistry. acids laid the true foundation of chemistry; in a political point of view, the invention of gunpowder revolutionized the world.

Gunpowder

works.

There were several explosive mixtures. Automatic fire was made from equal parts of sulphur, saltpetre, and fire- and sulphide of antimony, finely pulverized and mixed into a paste, with equal parts of juice of the black sycamore and liquid asphaltum, a little quicklime being added. It was directed to keep the material from the rays of the sun, which would set it on fire.

Of liquid or Greek fire we have not a precise description, since the knowledge of it was kept at Constantinople as a state secret. There is reason, however, to believe that it contained sulphur and nitrate of potash mixed with naphtha. Of gunpowder, Marcus Græcus, whose date is probably to be referred to the close of the eighth century, gives the composition explicitly. He directs us to pulverize in a marble mortar one pound of sulphur, two of charcoal, and six of saltpetre. If some of this powder be tightly rammed in a long narrow tube closed at one end, and then set on

fire, the tube will fly through the air: this is clearly the rocket. He says that thunder may be imitated by folding some of the powder in a cover and tying it up tightly: this is the cracker. It thus appears that fireworks preceded fire-arms. To the same author we are Incombusindebted for prescriptions for making the skin tible men. incombustible, so that we may handle fire without being burnt. These, doubtless, were received as explanations of the legends of the times, which related how miracleworkers had washed their hands in melted copper, and sat at their ease in flaming straw.

Among the Saracen names that might be mentioned as cultivators of alchemy, we may recall El-Rasi, Arabian Ebid Durr, Djafar or Geber, Toghragé, who chemists. wrote an alchemical poem, and Dschildegi, one of whose works bears the significant title of "The Lantern." The definition of alchemy by some of these authors is very striking the science of the balance, the science of weight, the science of combustion.

Djafar dis

regia,

To one of these chemists, Djafar, our attention may for a moment be drawn. He lived toward the end of the eighth century, and is honoured by Rhases, covers nitric Avicenna, and Kalid, the great Arabic phy- acid and aqua sicians, as their master. His name is memorable in chemistry, since it marks an epoch in that science of equal importance to that of Priestley and Lavoisier. He is the first to describe nitric acid and aqua regia. Before him no stronger acid was known than concentrated vinegar. We cannot conceive of chemistry as not possessing acids. Roger Bacon speaks of him as the magister magistrorum. He has perfectly just notions of the nature of spirits or gases, as we call them; thus he says, “O son of the doctrine, when spirits fix themselves in bodies, they lose their form; in their nature they are no longer oxidation what they were. When you compel them to increases be disengaged again, this is what happens: either the spirit alone escapes with the air, and the body remains fixed in the alembic, or the spirit and body escape together at the same time." His doctrine respecting the nature of the metals, though erroneous, was not without a scientific value. A metal he considers to

66

and that

weight.

He solves the problem of potable gold.

be a compound of sulphur, mercury, and arsenic, and hence he infers that transmutation is possible by varying the proportion of those ingredients. He knows that a metal, when calcined, increases in weight, a discovery of the greatest importance, as eventually brought to bear in the destruction of the doctrine of Phlogiston of Stahl, and which has been imputed to Europeans of a much later time. He describes the operations of distillation, sublimation, filtration, various chemical apparatus, waterbaths, sand-baths, cupels of bone-earth, of the use of which he gives a singularly clear description. A chemist reads with interest Djafar's antique method of obtaining nitric acid by distilling in a retort Cyprus vitriol, alum, and saltpetre. He sets forth its corrosive power, and shows how it may be made to dissolve even gold itself, by adding a portion of sal ammoniac. Djafar may thus be considered as having solved the grand alchemical problem of obtaining gold in a potable state. Of course, many trials must have been made on the influence of this solution on the animal system, respecting which such extravagant anticipations had been entertained. The disappointment that ensued was doubtless the reason that the records of these trials have not descended to us. With Djafar may be mentioned Rhazes, born A.D. 860, physician-in-chief to the great hospital at Bagdad. To him is due the first description of the preparation and properties of sulphuric acid. He obtained it, as the Nordhausen variety is still made, by the distillation of dried green vitriol. To him are also due the first indications of the preparation of absolute alcohol, by distilling spirit of wine from quick-lime. As a curious discovery made by the Saracens may covers phos- be mentioned the experiment of Achild Bechil, phorus. who, by distilling together the extract of urine, clay, lime, and powdered charcoal, obtained an artificial carbuncle, which shone in the dark "like a good moon." This was phosphorus.

Rhazes discovers sulphuric acid.

Bechil'dis

And now there arose among Arabian physicians a correctness of thought and breadth of view altogether surprising. It might almost be supposed that the following lines were written by one of our own contemporaries;

Avicenna.

they are, however, extracted from a chapter of Avicenna. on the origin of mountains. This author was Geological born in the tenth century. "Mountains may views of be due to two different causes. Either they are effects of upheavals of the crust of the earth, such as might occur during a violent earthquake, or they are the effect of water, which, cutting for itself a new route, has denuded the valleys, the strata being of different kinds, some soft, some hard. The winds and waters disintegrate the one, but leave the other intact. Most of the eminences of the earth have had this latter origin. It would require a long period of time for all such changes to be accomplished, during which the mountains themselves might be somewhat diminished in size. But that water has been the main cause of these effects is proved by the existence of fossil remains of aquatic and other animals on many mountains." Avicenna also explains the nature of petrifying or incrusting waters, and mentions ærolites, out of one of which a sword-blade was made, but he adds that the metal was too brittle to be of any use. A mere catalogue of some of the works of Avicenna will indicate the condition of Arabian attainment. 1. On the Utility and Advantage of Science; 2. Of Health indicate the and Remedies; 3. Canons of Physic; 4. On attainment of Astronomical Observations; 5. Mathematical Theorems; 6. On the Arabic Language and its Properties; 7. On the Origin of the Soul and Resurrection of the Body; 8. Demonstration of Collateral Lines on the Sphere; 9. An Abridgment of Euclid; 10. On Finity and Infinity; 11. On Physics and Metaphysics; 12. An Encyclopædia of Human Knowledge, in 20 vols., etc., etc. The perusal of such a catalogue is sufficient to excite profound attention when we remember the contempo· raneous state of Europe.

His works

the times.

elixir on

The pursuit of the elixir made a well-marked impression upon Arab experimental science, confirm- Effect of the ing it in its medical application. At the founda- search for the tion of this application lay the principle that practical it is possible to relieve the diseases of the human medicine. body by purely material means. As the science advanced it gradually shook off its fetichisms, the spiritual receding

into insignificance, the material coming into bolder relief. Not, however, without great difficulty was a way forced for the great doctrine that the influence of substances on the constitution of man is altogether of a material kind, and not at all due to any indwelling or animating spirit; that it is of no kind of use to practise incantations over drugs, or to repeat prayers over the mortar in which medicines are being compounded, since the effect will be the same, whether this has been done or not; that there is no kind of efficacy in amulets, no virtue in charms; and that, though saint-relics may serve to excite the imagination of the ignorant, they are altogether beneath the attention of the philosopher.

Medical con

flict between Europe and Africa.

It was this last sentiment which brought Europe and Africa into intellectual collision. The Saracen and Hebrew physicians had become thoroughly materialized. Throughout Christendom the practice of medicine was altogether supernatural. It was in the hands of ecclesiastics; and saint relics, shrines, and miracle-cures were a source of boundless profit. On a subsequent page I shall have to describe the circumstances of the conflict that ensued between material philosophy on one side, and supernatural jugglery on the other; to show how the Arab system gained the victory, and how, out of that victory, the industrial life of Europe arose. The Byzantine policy inaugurated in Constantinople and Alexandria was, happily for the world, in the end overthrown. To that future page I must postpone the great achievements of the Arabians in the fulness of their Age of Reason. When Europe was hardly more enlightened than Caffraria is now, the Saracens were cultivating and even creating science. Their triumphs in philosophy, mathematics, astronomy, chemistry, medicine, proved to be more glorious, more durable, and therefore more important than their military actions had been.

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