In Alexandria two streams of knowledge met and fused together... The ancient Egyptian industrial arts of metallurgy, dyeing and glass-making... and... the philosophical speculations of ancient Greece, now tinged with ancient mysticism, and partly transformed into that curious fruit of the tree of knowledge which we call Gnosticism. ...the result was the "divine" or "sacred" art (...also means sulphur) of making gold of silver. ...during the first four centuries a considerable body of knowledge came into existence. The treatises written in Greek... in Alexandria, are the earliest known books on chemistry. ...The treatises also contain much of an allegorical nature... sometimes described as "obscure mysticism." ...the Neoplatonism which was especially studied in Alexandria... is not so negligible as has sometimes been supposed. ...The study of astrology was connected with that of chemistry in the form of an association of the metals with the planets on a supposed basis of "sympathy". This goes back to early Chaldean sources but was developed by the Neoplatonists.

It was a great achievement of the early chemists — with the crude experimental techniques available also with the ever-astonishing power of human reason (as potent then as now) — to discover this reduction of the world to its components, the chemical elements. Such reduction does not destroy its charm but adds understanding to sensation, and this understanding only deepens our delight.

I appeal to the chemists to discover a humane gas that will kill instantly and painlessly. In short, a gentlemanly gas – deadly by all means, but humane not cruel.

I appeal to the chemists to discover a humane gas that will kill instantly and painlessly. In short - a gentlemanly gas deadly by all means, but humane, not cruel.

The first difficulty that faced us was the identification of the forms seen on focusing the sight on gases. We could only proceed tentatively. Thus, a very common form in the air had a sort of dumb-bell shape (see Plate I); we examined this, comparing our rough sketches, and counted its atoms; these, divided by 18—the number of ultimate atoms in hydrogen—gave us 23.22 as atomic weight, and this offered the presumption that it was sodium. We then took various substances—common salt, etc.—in which we knew sodium was present, and found the dumb-bell form in all. In other cases, we took small fragments of metals, as iron, tin, zinc, silver, gold; in others, again, pieces of ore, mineral waters, etc., etc.... In all, 57 chemical elements were examined, out of the 78 recognized by modern chemistry. In addition to these, we found 3 chemical waifs: an unrecognized stranger between hydrogen and helium which we named occultum, for purposes of reference, and 2 varieties of one element, which we named kalon and meta-kalon, between xenon and osmium... Thus we have tabulated in all 65 chemical elements, or chemical atoms, completing three of Sir William Crookes' lemniscates, sufficient for some amount of generalization. (Chapter III. The Later Researches)

The first difficulty that faced us was the identification of the forms seen on focusing the sight on gases. We could only proceed tentatively. Thus, a very common form in the air had a sort of dumb-bell shape (see Plate I); we examined this, comparing our rough sketches, and counted its atoms; these, divided by 18—the number of ultimate atoms in hydrogen—gave us 23.22 as atomic weight, and this offered the presumption that it was sodium. We then took various substances—common salt, etc.—in which we knew sodium was present, and found the dumb-bell form in all. In other cases, we took small fragments of metals, as iron, tin, zinc, silver, gold; in others, again, pieces of ore, mineral waters, etc., etc.... In all, 57 chemical elements were examined, out of the 78 recognized by modern chemistry. In addition to these, we found 3 chemical waifs: an unrecognized stranger between hydrogen and helium which we named occultum, for purposes of reference, and 2 varieties of one element, which we named kalon and meta-kalon, between xenon and osmium... Thus we have tabulated in all 65 chemical elements, or chemical atoms, completing three of Sir William Crookes' lemniscates, sufficient for some amount of generalization. (Chapter III. The Later Researches)

A spectacular anomaly came up with the hydrides of the nonmetals—an ugly bunch, about as inimical to life as one could get. Arsenic and antimony hydrides were very poisonous and smelly; silicon and phosphorous hydrides were spontaneously inflammable. I had made in my lab the hydrides of sulfur (H₂S), selenium (H₂Se), and tellurium (H₂Te), all Group VI elements, all dangerous and vile-smelling gases. The hydride of oxygen, the first Group VI element, one might predict by analogy, would be a foul-smelling, poisonous, inflammable gas, too, condensing to a nasty liquid around −100°C. And instead it was water, H₂O—stable, potable, odorless, benign, and with a host of special, indeed unique properties (its expansion when frozen, its great heat capacity, its capacity as an ionizing solvent, etc.) which made it indispensable to our watery planet, indispensable to life itself. What made it such an anomaly? […] (This question, I found, had only been resolved recently, in the 1930s, with Linus Pauling's delineation of the hydrogen bond.)

They can picture love affairs of chemicals and stars, a romance of stones, or the fertility of fire. Strange, fertile correspondences the alchemists sensed in unlikely orders of being. Between men and planets, plants and gestures, words and weather.

The Greek chemical treatises contain... a great amount of practical chemical information... fusion, calcination, solution, filtration, crystallization, sublimation and especially distillation; and methods of heating include the open fire, lamps, and the sand and water baths. Nearly all this practical knowledge... the Arabs... derived... from the very source we are now considering.

Were we really more advanced than the alchemists of Carmona? We had brought to light certain facts that they were not aware of, we had organised them into the right order; but had we advanced even a step nearer to the mysterious heart of the universe?

The earliest chemical theory was qualitative in the strictest sense; the so-called Aristotelean doctrine of the four elements assumed that air, water, earth, and fire, were qualities impressed on a primal matter; and the changes of material bodies were explained by the assumption that properties could be taken up by, and impressed upon, or removed from, the base-stuff. Transmutation as a possibility followed at once, and centuries of vain endeavour were required to impress the fact of its impossibility, leading to the true concept of element.

A quarter of a century ago, when the were first discovered, all scholars were struck by their likeness to the works of later Greece. Even now, when the knowledge of dissimilarities in detail has obscured for many minds this broad resemblance, no one would assert that a or is impossible.

It can scarcely be denied that the fundamental phenomena which first led mankind into chemical inquiries are those of combustion. But, as we have just seen, minimized beings would be unable to produce fire at will, except by certain chemical reactions, and would have little opportunity of examining its nature. They might occasionally witness forest fires, volcanic eruptions, etc.; but such grand and catastrophic phenomena, though serving to reveal to our supposed Lilliputians the existence of combustion, would be ill suited for quiet investigation into its conditions and products. Moreover, considering the impossibility they would experience of pouring water from one test tube to another, the ordinary operations of analytical chemistry and of all manipulations depending on the use of the pneumatic trough would remain forever a sealed book.

Where [our great-grandfathers] interpreted the motions of planets in our own solar system, we discuss the chemical constitution of stars, many of which... their telescopes could not reach... Where they discovered the circulation of the blood, we see the physical conflict of living poisons within the blood whose battles would have been absurdities for them. Where they found void... we conceive of great systems in rapid motion capable of carrying through brick walls as light passes through glass. Great as the advance of scientific knowledge has been, it has not been greater than the growth of the material to be dealt with. The universe grows ever larger as we learn to understand more of our own corner of it.