CHAPTER V

ANCIENT APPLIED SCIENCE AND MAGIC: VITRUVIUS, HERO, AND THE GREEK ALCHEMISTS The sources—Vitruvius depicts architecture as free from magic—But himself believes in occult virtues and perfect numbers—Also in astrology—Divergence between theory and practice, learning and art—Evils in contemporary learning—Authorities and inventions—Machines and Ctesibius—Hero of Alexandria—Medieval working over of the texts—Hero’s thaumaturgy—Instances of experimental proof—Magic jugs and drinking animals—Various automatons and devices—Magic mirrors—Astrology and occult virtue—Date of extant Greek alchemy—Legend that Diocletian burned the books of the alchemists—Alchemists’ own accounts of the history of their art—Close association of Greek alchemy with magic—Mystery and allegory—Experiment: relation to science and philosophy. “_doctum ex omnibus solum neque in alienis locis peregrinum ... sed in omni civitate esse civem._” —_Vitruvius, VI, Introd. 2._ [Sidenote: The sources.] This chapter will examine what may be called ancient applied science and its relations to magic, taking observations at three different points, the ten books of Vitruvius on architecture, the collection of writings which pass under the name of Hero of Alexandria, and the compositions of the Greek alchemists. The remains of Greek and Roman literature in the field of applied science are scanty, not because they were not treasured, and even added to, by the periods following, but apparently because there had thus far been so little development in the way of machinery or of power other than manual and animal. So we must make the best of what we have. The writings to be considered are none of them earlier than the period of the Roman Empire but like other writings of that time they more or less reflect the scientific achievements or the occult lore of the preceding Hellenistic period. [Sidenote: Vitruvius depicts architecture as free from magic.] Vitruvius lived just at the beginning of the Empire under Julius and Augustus Caesar. He is not much of a writer, but architecture as set forth in his book appears sane, straightforward, and solid. The architect is represented as going about his business with scarcely any admixture of magical procedure or striving after marvelous results. The combined guidance of practical utility and of high standards of art—Vitruvius stresses reality and propriety now and again, and has little patience with mere show—perhaps accounts for this high degree of freedom from superstition. Perhaps permanent building is an honest, downright, open, constructive art where error is at once apparent and superstition finds little hold. If so, one wonders how there came to be so much mystery enveloping Free-Masonry. At any rate, not only in his building directions, but even in his instructions for the preparation of lime, stucco, and bricks, or his discussion of colors, natural and artificial, Vitruvius seldom or never embodies anything that can be called magical.[858] [Sidenote: Occult virtue and number.] This is the more noteworthy because passages in the very same work show him to have accepted some of the theories which we have associated with magic. Thus he appears to believe in occult virtues and marvelous properties of things in nature, since he affirms that, while Africa in general abounds in serpents, no snake can live within the boundaries of the African city of Ismuc, and that this is a property of the soil of that locality which it retains when exported.[859] Vitruvius also mentions some marvelous waters. One breaks every metallic receptacle and can be retained only in a mule’s hoof. Some springs intoxicate; others take away the taste for wine. Others produce fine singing voices.[860] Vitruvius furthermore speaks of six and ten as perfect numbers and contends that the human body is symmetrical in the sense that the distances between the different parts are exact fractions of the whole.[861] He also tells how the Pythagoreans composed books on the analogy of the cube, allowing in any one treatise no more than three books of 216 lines each.[862] [Sidenote: Astrology.] Vitruvius also more than once implies his confidence in the art of astrology. In mapping out the ground-plan of his theater he advises inscribing four equilateral triangles within the circumference of a circle, “as the astrologers do in a figure of the twelve signs of the zodiac, when they are making computations from the musical harmony of the stars.”[863] I cannot make out that there is any astrological significance or magical virtue in this so far as the arrangement of the theater is concerned, but it shows that Vitruvius and his readers are familiar with the technique of astrology and the _trigona_ of the signs. In another passage, comparing the physical characteristics and temperaments of northern and southern races, which astrologers generally interpreted as evidence of the influence of the constellations upon mankind, Vitruvius patriotically contends that the inhabitants of Italy, and especially the Romans, represent a happy medium between north and south, combining the greater courage of the northerners with the keener intellects of the southerners, just as the planet Jupiter is a golden mean between the extreme influences of Mars and Saturn. So the Romans are fitted for world rule, overcoming barbarian valor by their superior intelligence and the devices of the southerners by their valor.[864] In a third passage Vitruvius says more expressly of the art of astrology: “As for the branch of astronomy which concerns the influences of the twelve signs, the five stars, the sun, and the moon upon human life, we must leave all this to the calculations of the Chaldeans, to whom belongs the art of casting nativities, which enables them to declare the past and the future by means of calculations based on the stars. These discoveries have been transmitted by men of genius and great acuteness who sprang directly from the nations of the Chaldeans; first of all, by Berosus, who settled in the island state of Cos, and there opened a school. Afterwards Antipater pursued the subject; then there was Archinapolus, who also left rules for casting nativities, based not on the moment of birth but on that of conception.” After listing a number of natural philosophers and other astronomers and astrologers, Vitruvius concludes: “Their learning deserves the admiration of mankind; for they were so solicitous as even to be able to predict, long beforehand, with divining mind, the signs of the weather which was to follow in the future.”[865] [Sidenote: Divergence between theory and practice, learning and art.] Such a passage demonstrates plainly enough Vitruvius’ full confidence in the art of casting nativities and of weather prediction, but it has no integral connection with his practical architecture or even any necessary connection with the construction of a sun-dial, which is what he is actually driving at. But Vitruvius believed that an architect should not be a mere craftsman but broadly educated in history, medicine, and philosophy, geometry, music, and astronomy, in order to understand the origin and significance of details inherited from the art of the past, to assure a healthy building, proper acoustics, and the like. It is in an attempt to air his learning and in the theoretical portions of his work that he is prone to occult science. But the practical processes of architecture and military engineering are free from it. [Sidenote: Evils in contemporary learning.] The attitude of Vitruvius towards other architects of his own age, to past authorities, and to personal experimentation is of interest to note, and roughly parallels the attitude of Galen in the field of medicine. Like Galen he complains that the artist must plunge into the social life of the day in order to gain professional success and recognition.[866] “And since I observe that the unlearned rather than the learned are held in high favor, deeming it beneath me to struggle for honors with the unlearned, I will rather demonstrate the virtue of our science by this publication.”[867] He also objects to the self-assertion and advertising of themselves in which many architects of his time indulge.[868] He recognizes, however, that the state of affairs was much the same in time past, since he tells a story how the Macedonian architect, Dinocrates, forced himself upon the attention of Alexander the Great solely by his handsome and stately appearance,[869] and since he asserts that the most famous artists of the past owe their celebrity to their good fortune in working for great states or men, while other artists of equal merit are seldom heard of.[870] He also speaks of those who plagiarize the writings of others, especially of the men of the past.[871] But all this does not lead him to despair of art and learning; rather it confirms him in the conviction that they alone are really worth while, and he quotes several philosophers to that effect, including the saying of Theophrastus that “the learned man alone of all others is no stranger even in foreign lands ... but is a citizen in every city.”[872] [Sidenote: Authorities and inventions.] In contradistinction to the plagiarists Vitruvius expresses his deep gratitude to the men of the past who have written books, and gives lists of his authorities,[873] and declares that “the opinions of learned authors ... gain strength as time goes on.”[874] “Relying upon such authorities, we venture to produce new systems of instruction.”[875] Or, as he says in discussing the properties of waters, “Some of these things I have seen for myself, others I have found written in Greek books.”[876] But in describing sun-dials he frankly remarks, “I will state by whom the different classes and designs of dials have been invented. For I cannot invent new kinds myself at this late day, nor do I think that I ought to display the inventions of others as my own.”[877] He also gives an account of a number of notable miscellaneous discoveries and experiments by past mathematicians and physicists.[878] Also he sometimes repeats the instruction which he had received from his teachers. Like Pliny a little later he thinks that in some respects artistic standards have been lowered in his own time, notably in fresco-painting.[879] But also, like Galen, he once admits that there are still good men in his own profession besides himself, affirming that “our architects in the old days, and a good many even in our own times, have been as great as those of the Greeks.”[880] He describes a basilica which he himself had built at Fano.[881] [Sidenote: Machines and Ctesibius.] Vitruvius’s last book is devoted to machines and military engines. Here he makes a feeble effort to introduce the factor of astrological influence, asserting that “all machinery is derived from nature, and is founded on the teaching and instruction of the revolution of the firmament.”[882] Among the devices described is the pump of Ctesibius of Alexandria, the son of a barber.[883] He had already been mentioned in the preceding book[884] for the improvements which he introduced in water-clocks, especially regulating their flow according to the changing length of the hours of the day in summer and winter. Vitruvius also asserts that he constructed the first water organs, that he “discovered the natural pressure of the air and pneumatic principles, ... devised methods of raising water, automatic contrivances, and amusing things of many kinds, ... blackbirds singing by means of waterworks, and _angobatae_, and figures that drink and move, and other things that have been found to be pleasing to the eye and the ear.”[885] Vitruvius states that of these he has selected those that seemed most useful and necessary and that the reader may turn to Ctesibius’s own works for those which are merely amusing. Pliny more briefly mentions the invention of pneumatics and water organs by Ctesibius.[886] [Sidenote: Hero of Alexandria.] This characterization by Vitruvius of the writings of Ctesibius also applies with astonishing fitness to some of the works current under the name of Hero of Alexandria,[887] who is indeed in a Vienna manuscript of the _Belopoiika_ spoken of as the disciple or follower of Ctesibius.[888] Hero, however, is not mentioned either by Vitruvius or Pliny, and it is now generally agreed as a result of recent studies that he belongs to the second century of our era.[889] His writings are objective and impersonal and tell us much less about himself than Vitruvius’s introductions to the ten books of _De architectura_. The similarity in content of his writings to those of the much earlier Ctesibius as well as the character of his terminology suggest that he stands at the end of a long development. He speaks of his own discoveries, but perhaps in the main simply continues and works over the previous principles and mechanisms of men like Ctesibius. As things stand, however, his works constitute our most important, and often our only, source for the history of exact science and of technology in antiquity.[890] [Sidenote: Medieval working over of the texts.] Not only does Hero seem to have been in large measure a compiler and continuer of previous science, his works also have evidently been worked over and added to in subsequent periods and bear marks of the Byzantine, Arabian, and medieval Latin periods as well as of the Hellenistic and Roman. Indeed Heiberg regards the _Geometry_ and _De stereometricis_ and _De mensuris_ as later Byzantine collections which have perhaps made some use of the works of Hero, while the _De geodaesia_ is an epitome of, or extract from, a pseudo-Heronic collection. The _Catoptrica_ is known only from the Latin translation of 1269, probably by William of Moerbeke, and long known as _Ptolemy on Mirrors_. It appears, however, to be directly translated from the Greek and not from the Arabic. The _Mechanics_, on the other hand, is known only from the Arabic translation by Costa ben Luca. Of the _Pneumatics_ we have Greek, Arabic, and Latin versions. It was apparently known to the author of the thirteenth century _Summa philosophiae_ ascribed to Robert Grosseteste, since he speaks of the investigations of vacuums made by “Hero, that eminent philosopher, with the aid of water-clocks, siphons, and other instruments.”[891] Scholars are of the opinion that the Arabic adaptation, which is of popular character and limited to the entertaining side, comes closer to the original Greek version of Hero’s time than does the Latin version which devotes more attention to experimental physics. The _Automatic Theater_, for which there is the same chief manuscript as for the _Pneumatics_, also seems to have been worked over and added to a great deal. [Sidenote: Hero’s thaumaturgy.] From Vitruvius’s allusions to the works of Ctesibius and from a survey of those works current under Hero’s name which are chiefly concerned with mechanical contrivances and devices, the modern reader gets the impression that, aside from military engines and lifting appliances, the science of antiquity was applied largely to purposes of entertainment rather than practical usefulness. However, in Hero’s case at least there is something more than this. His apparatus and experiments are not intended so much to divert as to deceive the spectator, and not so much to amuse as to astound him. The mechanism is usually concealed; the cause acts indirectly, intermediately, or from a distance to produce an apparently marvelous result. It is a case of thaumaturgy, as Hero himself says,[892] of apparent magic. In fine, the experimental and applied scientist is largely interested in vying with the feats of the magicians or supplying the temples and altars of religion with pseudo-miracles. [Sidenote: Instances of experimental proof.] The introduction or proemium to the _Pneumatics_ is rather more truly scientific and has been called an unusual instance in antiquity of the use as proof of purposive observation of nature and experiment. Thus the existence of air is demonstrated by the experiment of pressing an inverted vessel, kept carefully upright, into water, which will not enter the vessel because of the resistance offered by the air already within the vessel. Or the elasticity of air and the existence of empty spaces between its particles is shown by the experiment of blowing more air into a globe through a siphon, and then holding one’s finger over the orifice. As soon as the finger is removed the surplus air rushes out with a loud report. Along with such admirable experimental proof, however, the introduction contains some astonishingly erroneous assertions, such as that “slime and mud are transformations of water into earth,” and that air released from a vessel under water “is transformed so as to become water.” Hero believes that heat and light rays are particles of matter which penetrate the interstices between the particles composing air and water. [Sidenote: Magic jugs and drinking animals.] The _Pneumatics_ consist of some seventy-eight theorems or experiments or tricks, call them what you will, which in different manuscripts and editions are variously grouped in a single book or two books. The same idea or method, however, is often repeated in the different chapters. Thus we encounter over half a dozen times the magic water-jar or drinking horn from which either wine or water or a mixture of both can be poured, or a choice of other liquids. And in all these cases the explanation of the trick is the same. When the air-hole in the top of the vessel is closed so that no air can enter, the liquid will not flow out through the narrow orifice in the bottom. Changes are rung on this principle by means of inner compartments and connecting tubes. Different kinds of siphons, the bent, the enclosed, and the uniform discharge, are described in the opening chapters and are utilized in working the ensuing wonders, such as statues of animals which drink water offered to them, inexhaustible goblets or those that will not overflow, and harmonious jars. By this last expression is meant pairs of vessels, secretly connected by tubes and so arranged that nothing will flow from one until the other is filled, when wine will pour from one jar and water from the other. Or when water is poured into one jar, wine or mixed wine and water flows from the other. Or, when water is drawn off from one jar, wine flows from the other. Other vessels are made to commence or cease to pour out wine or water, when a little water is poured in. Others will receive no more water once you have ceased pouring it in, no matter how little may have been poured in, or, when you cease for a moment to pour water in and then begin again, will not resume their outpour until half full. In another case the water will not flow out of a hole in the bottom of the vessel at all until the vessel is entirely filled. Others are made to flow by dropping a coin in a slot or working a lever, or turning a wheel. In the last case the vessel of water is concealed behind the entrance column of a temple. In one magic drinking horn the flow of water from the bottom is checked by putting a cover over the open top. When another pitcher is tipped up, the same amount of liquid will always flow out. [Sidenote: Various automatons and devices.] In half a dozen chapters mechanical birds are made to sing by driving air through a pipe by the pressure of flowing water. In other chapters a dragon is made to hiss and a thyrsus to whistle by similar methods. By the force of compressed air water is made to spurt forth and automatons to sound trumpets. The heat of the sun’s rays is used to warm air which expands and causes water to trickle out. In a number of cases as long as a fire burns on an altar the expansion of enclosed air caused thereby opens temple doors by the aid of pulleys, or causes statues to pour libations, dancing figures to revolve, and a serpent to hiss. The force of steam is used to support a ball in mid-air, revolve a sphere, and make a bird sing or a statue blow a horn. Inexhaustible lamps are described as well as inexhaustible goblets, and a self-trimmed lamp in which a float resting on the oil turns a cog-wheel which pushes up the wick as it and the oil are consumed. Floats and cog-wheels are also used in some of the tricks already mentioned. In another the flow of a liquid from a vessel is regulated by a float and a lever. Cog-wheels are also employed in constructing the neck of an automaton so that it can be cut completely through with a knife and yet the head not be severed from the body. A cupping glass, a syringe, a fire engine pump with valves and pistons, a hydraulic organ and one worked by wind pretty much exhaust the contents of the _Pneumatics_. In its introduction Hero alludes to his treatise in four books on water-clocks, but this is not extant. Hero’s water-organ is regarded as more primitive than that described by Vitruvius.[893] [Sidenote: Magic mirrors.] If magic jugs and marvelous automatons make up most of the contents of the _Pneumatics_ and _Automatic Theater_, comic and magic mirrors play a prominent part in the _Catoptrics_. The spectator sees himself upside down, with three eyes, two noses, or an otherwise distorted countenance. By means of two rectangular mirrors which open and close on a common axis Pallas is made to spring from the head of Zeus. Instructions are given how to place mirrors so that the person approaching will see no reflection of himself but only whatever apparition you select for him to see. Thus a divinity can be made suddenly to appear in a temple. Clocks are also described where figures appear to announce the hours. [Sidenote: Astrology and occult virtue.] Hero displays a slight tendency in the direction of astrology, discussing the music of the spheres in the first chapters of the _Catoptrics_, and in the _Pneumatics_ describing an absurdly simple representation of the cosmos by means of a small sphere placed in a circular hole in the partition between two halves of a transparent sphere of glass. One hemisphere is to be filled with water, probably in order to support the ball in the center.[894] The marvelous virtues of animals other than automatons are rather out of his line, but he alludes to the virtue of the marine torpedo which can penetrate bronze, iron, and other bodies. [Sidenote: Date of extant Greek alchemy.] Although we have seen some indications of its earlier existence in Egypt, alchemy seems to have made its appearance in the ancient Greek-speaking and Latin world only at a late date. There seems to be no allusion to the subject in classical literature before the Christian era, the first mention being Pliny’s statement that Caligula made gold from orpiment.[895] The papyri containing alchemistic texts are of the third century, and the manuscripts containing Greek works of alchemy, of which the oldest is one of the eleventh century in the Library of St. Mark’s, seem to consist of works or remnants of works written in the third century and later, many being Byzantine compilations, excerpts, or additions. Also Syncellus, the polygraph of the eighth century, gives some extracts from the alchemists. [Sidenote: Legend that Diocletian burned the books of the alchemists.] Syncellus and other late writers[896] are our only extant sources for the statement that Diocletian burned the books of the alchemists in Egypt, so that they might not finance future revolts against him. If the report be true, one would fancy that the imperial edict would be more effective as a testimonial to the truth of transmutation in encouraging the art than it would be in discouraging it by destroying a certain amount of its literature. Thus the edict would resemble the occasional laws of earlier emperors banishing the astrologers—except their own—from Rome or Italy because they had been too free in predicting the death of the emperor, which only serve to show what a hold astrology had both on emperors and people. But the report concerning Diocletian sounds improbable on the face of it and must be doubted for want of contemporary evidence. Certainly we are not justified in explaining the air of secrecy so often assumed by writers on alchemy as due to the fear of persecution which this action of Diocletian[897] or the fear of being accused of magic aroused in them. Persons who wish to keep matters secret do not rush into publication, and the air of secrecy of the alchemists is too often evidently assumed for purposes of show and to impress the reader with the idea that they really have something to hide. Sometimes the alchemists themselves realize that this adoption of an air of secrecy has been overdone. Thus Olympiodorus wrote in the early fifth century, “The ancients were accustomed to hide the truth, to veil or obscure by allegories what is clear and evident to everybody.”[898] Nor can we accept the story of Diocletian’s burning the books of alchemy as the reason why none have reached us which can be certainly dated as earlier than the third century. [Sidenote: Alchemists’ own accounts of the history of their art.] The alchemists themselves, of course, claimed for their art the highest antiquity. Zosimus of Panopolis, who seems to have written in the third century, says that the fallen angels instructed men in alchemy as well as in the other arts, and that it was the divine and sacred art of the priests and kings of Egypt, who kept it secret. We also have an address of Isis to her son Horus repeating the revelation made by Amnael, the first of the angels and prophets. To Moses are ascribed treatises on domestic chemistry and doubling the weight of gold.[899] The manuscripts of the Byzantine period discuss what “the ancients” meant by this or that, or purport to repeat what someone else said of some other person. Zosimus seems fond of citing himself in the texts reproduced by Berthelot, so that it may be questioned how much of his original works has been preserved. Hermes is often cited by the alchemists, although no work of alchemy ascribed to him has reached us from this early period. To Agathodaemon is ascribed a commentary on the oracle of Orpheus addressed to Osiris, dealing with the whitening and yellowing of metals and other alchemical recipes. Other favorite authorities are Ostanes, whom we have elsewhere heard represented as the introducer of magic into the Greek world, and the philosopher Democritus, whom the alchemists represent as the pupil of Ostanes and whom we have already heard Pliny charge with devotion to magic. Seneca says in one of his letters that Democritus discovered a process to soften ivory, that he prepared artificial emerald, and colored vitrified substances. Diogenes Laertius ascribes to him a work on the juices of plants, on stones, minerals, metals, colors, and coloring glass. This was possibly the same as the four books on coloring gold, silver, stones, and purple ascribed to Democritus by Synesius in the fifth, and Syncellus in the eighth, century. More recent presumably than Ostanes and Democritus are the female alchemists, Cleopatra and Mary the Jewess, although one text represents Ostanes and his companions as conversing with Cleopatra. A few of the spurious works ascribed to these authors may have come into existence as early as the Hellenistic period, but those which have reached us, at least in their present form, seem to bear the marks of the Christian era and later centuries of the Roman Empire, if not of the early medieval and Byzantine periods. And those authors whose names seem genuine: Zosimus, Synesius, Olympiodorus, Stephanus, are of the third, fourth and fifth centuries, at the earliest. [Sidenote: Close association of Greek alchemy with magic.] The associations of the names above cited and the fact that pseudo-literature forms so large a part of the early literature of alchemy suggest its close connection at that time with magic. Whereas Vitruvius, although not personally inhospitable to occult theory, showed us the art of architecture free from magic, and Hero told how to perform apparent magic by means of mechanical devices and deceits, the Greek alchemists display entire faith in magic procedure with which their art is indissolubly intermingled. Indeed the papyri in which works of alchemy occur are primarily magic papyri, so that alchemy may be said to spring from the brow of magic. The same is only somewhat less true of the manuscripts. In the earliest one of the eleventh century the alchemy is in the company of a treatise on the interpretation of dreams, a sphere of divination of life or death, and magic alphabets. The treatises of alchemy themselves are equally impregnated with magic detail. Cleopatra’s art of making gold employs concentric circles, a serpent, an eight-rayed star, and other magic figures. _Physica et mystica_, ascribed to Democritus, after a purely technical fragment on purple dye, invokes his master Ostanes from Hades, and then plunges into alchemical recipes. There are also frequent bits of astrology and suggestions of Gnostic influence. Often the encircling serpent Ouroboros, who bites or swallows his tail, is referred to.[900] Sometimes the alchemist puts a little gold into his mixture to act as a sort of nest egg, or mother of gold, and encourage the remaining substance to become gold too.[901] Or we read in a work ascribed to Ostanes of “a divine water” which “revives the dead and kills the living, enlightens obscurity and obscures what is clear, calms the sea and quenches fire. A few drops of it give lead the appearance of gold with the aid of God, the invisible and all-powerful....”[902] [Sidenote: Mystery and allegory.] These early alchemists are also greatly given to mystery and allegory. “Touch not the philosopher’s stone with your hands,” warns Mary the Jewess, “you are not of our race, you are not of the race of Abraham.”[903] In a tract concerning the serpent Ouroboros we read, “A serpent is stretched out guarding the temple. Let his conqueror begin by sacrifice, then skin him, and after having removed his flesh to the very bones, make a stepping-stone of it to enter the temple. Mount upon it and you will find the object sought. For the priest, at first a man of copper, has changed his color and nature and become a man of silver; a few days later, if you wish, you will find him changed into a man of gold.”[904] Or in the preparation of the aforesaid divine water Ostanes tells us to take the eggs of the serpent of oak who dwells in the month of August in the mountains of Olympus, Libya, and the Taurus.[905] Synesius tells that Democritus was initiated in Egypt at the temple of Memphis by Ostanes, and Zosimus cites the instruction of Ostanes, “Go towards the stream of the Nile; you’ll find there a stone; cut it in two, put in your hand, and take out its heart, for its soul is in its heart.”[906] Zosimus himself often resorts to symbolic jargon to obscure his meaning, as in the description of the vision of a priest who was torn to pieces and who mutilated himself.[907] He, too, personifies the metals and talks of a man of gold, a tin man, and so on.[908] A brief example of his style will have to suffice, as these allegories of the alchemists are insufferably tedious reading. “Finally I had the longing to mount the seven steps and see the seven chastisements, and one day, as it chanced, I hit upon the path up. After several attempts I traversed the path, but on my return I lost my way and, profoundly discouraged, seeing no way out, I fell asleep. In my dream I saw a little man, a barber, clothed in purple robe and royal raiment, standing outside the place of punishment, and he said to me....”[909] When Zosimus was not dreaming dreams and seeing visions, he was usually citing ancient authorities. [Sidenote: Experimentation in alchemy: relation to science and philosophy.] At the same time even these early alchemists cannot be denied a certain scientific character, or at least a connection with natural science. Behind alchemy existed a constant experimental progress. “Alchemy,” said Berthelot, “rested upon a certain mass of practical facts that were known in antiquity and that had to do with the preparation of metals, their alloys, and that of artificial precious stones; it had there an experimental side which did not cease to progress during the entire medieval period until positive modern chemistry emerged from it.”[910] The various treatises of the Greek alchemists describe apparatus and experiments which are real but with which they associated results which were impossible and visionary. Their theories of matter seem indebted to the earlier Greek philosophers, while in the description of nature Berthelot noted a “direct and intimate” relation between them and the works of Dioscorides, Vitruvius, and Pliny.[911]