fruits, may we not reasonably expect that duly regulated degrees of fire will answer the purpose? by an exposure of base material in the furnace for a proper season, may we not anticipate the wished for event? The Emperor Caligula, who had formerly tried to make gold from Philosopher's orpiment by the force of fire, was only one of a stone. thousand adepts pursuing a similar scheme. Some trusted to the addition of a material substance in aiding the fire to purge away the dross of the base body submitted to it. From this arose the doctrine of the powder of projection and the philosopher's stone.

This doctrine of the possibility of transmuting things into forms essentially different steadily made its way, leading, in the material direction, to alchemy, Transmutathe art of making gold and silver out of baser tion and metals, and in theology to transubstantiation. transubstanTransmutation and transubstantiation were twin sisters, destined for a world-wide celebrity; one became allied to the science of Mecca, the other to the theology of Rome.

tiation.

While thus the Arabs joined in the pursuit of alchemy, their medical tendencies led them simultaneously to cultivate another ancient delusion, the discovery of a The elixir of universal panacea or elixir which could cure all life. diseases and prolong life for ever. Mystical experimenters for centuries had been ransacking all nature, from the yellow flowers which are sacred to the sun, and gold his emblem and representative on earth, down to the vilest excrements of the human body. As to gold, there had been gathered round that metal many fictitious excellences in addition to its real values; it was believed that in some preparation of it would be found the elixir vitæ. This is the explanation of the unwearied attempts Potable gold. at making potable gold, for it was universally thought that if that metal could be obtained in a dissolved state, it would constitute the long-sought panacea. Nor did it seem impossible so to increase the power of water as to impart to it new virtues, and thereby enable it to accomplish the desired solution. Were there not natural waters of very different properties? were there not some that could fortify the memory, others destroy it; some re-enforce the

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." definition of alchemy by some of these authors is very striking the science of the balance, the science of weight, the science of combustion.

:

66

The

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 Arabio 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 VOL. I-19

66

and that

weight.

He solves the problem of

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 potable gold. 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