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The Poet of Chemistry

At this time, there still existed a union of literary and scientific cultures; there was not the dissociation of sensibility that was so soon to come. There was indeed, between Coleridge and Davy, a passionate parallelism, a sense of an almost mystical affinity and rapport. Coleridge planned, at one point, to set up a chemical laboratory with Davy. The poet and the chemist, metaphorically, were fellow warriors, analyzers and explorers of a principle of connectedness of mind and nature. In Coleridge’s words,

Water and flame, the diamond, the charcoal…are convoked and fraternized by the theory of the chemist…. It is the sense of a principle of connection given by the mind, and sanctioned by the correspondency of nature….If in a Shakespeare we find nature idealized into poetry, through the creative power of a profound yet observant meditation, so through the meditative observation of a Davy…we find poetry, as it were, substantiated and realized in nature: yea, nature itself disclosed to us,…as at once the poet and the poem!

Coleridge and Davy seemed to see themselves as twins: Coleridge the chemist of language, Davy the poet of chemistry—both explorers of the divine “I am.”

In the eighteenth century static electricity was known, but no sustained electric current was possible until Alessandro Volta published in 1800 the discovery of his “pile,” a sandwich of two different metals, with brine-dampened cardboard in between, which generated a steady electric current—the first battery. Volta’s paper, Davy was later to write, acted like an alarm bell among the experimenters of Europe, and, for Davy, suddenly gave form to what he would now see as his life’s work. As Knight writes:

The clockwork universe so detested by Romantic thinkers was an obsolete conception; beneath the apparent solidity and stability of matter lay polar forces in equilibrium. Newton had understood gravitation, but the new Newton would come to grips with these new forces and create a dynamic science to replace the mechanical world view.

The key to this, Davy felt, would come through the use of electricity. He persuaded Beddoes to build a large electric battery, and started his first experiments with it in 1800. He suspected almost at once that its current was generated by chemical changes in the metal plates, and wondered if the reverse was also true—that one might induce chemical changes by the passage of an electric current. He started to make ingenious (and radical) modifications of the battery. And he was the first to make use of the enormous new power available to make a new form of illumination, the carbon arc-lamp.

These brilliant advances excited attention in the capital, and in that same year he was invited to the newly founded Royal Institution in London. This opened a new chapter in his life. He had always been eloquent, and a natural storyteller, and now he was to become the most famous and influential lecturer in England, drawing huge crowds that blocked the streets whenever he lectured. His lectures moved from the most intimate details of his experiments—reading them gives a vivid view of work in progress, of the activity of an extraordinary mind—to speculation about the universe and life, delivered in a style and with a richness of language that nobody else could match.4 Even Coleridge, the greatest talker of his age, always came to Davy’s lectures, not only to fill his chemical notebooks, but “to renew my stock of metaphors.”5

Chemistry was conceived, in Davy’s time, to embrace not only chemical reactions proper, but the study of heat, light, magnetism and electricity, much of what was later to be separated off as “physics” (even at the end of the century, the Curies first regarded radioactivity as a “chemical” property of certain elements). There was an extra-ordinary appetite for science, especially chemistry, at this time, in the early, palmy days of the Industrial Revolution; it seemed a new and powerful (and not irreverent) way not only of understanding the world but moving it to a better state. This double view of science found its perfect exponent in Davy. “In this view,” as he said in his inaugural lecture,

we do not look to distant ages, or amuse ourselves with brilliant but delusive dreams concerning the infinite improveability of man, the annihilation of labour, disease, and even death, but we reason by analogy from simple facts, we consider only a state of human progression arising out of its present condition—we look for a time that we may reasonably expect—for a bright day, of which we already behold the dawn.

In these first years of the Royal Institution, Davy put aside his larger speculations and concentrated on particular practical problems: problems of tanning, and the isolation of tannin (he was the first to find it in tea); and a whole range of agricultural problems—he was the first to recognize the vital role of nitrogen, and the importance of ammonia in fertilizers (his Elements of Agricultural Chemistry was published in 1813). There is no sign that Davy was impatient with such science, or felt himself in any way to be above such humdrum problems. (In this he resembles Pasteur, who did not disdain to work on the practical problems of viniculture, but was led from these to the most general ideas on fermentation and life.)

In 1806, however, established as the most brilliant lecturer and practical chemist in England—and still only twenty-seven—Davy felt he needed to give up his research obligations at the Royal Institution, and return to the fundamental concerns of his Bristol days. He had long wondered whether an electric current could provide a new way of isolating chemical elements, and now, freed from the pressure of other research, he could go back and put this to the test. He began experimenting with the electrolysis of water, using an electric current to split it into its component elements and showing that these combined in exact proportions.

The following year he performed the famous experiments which isolated metallic potassium and sodium by electric current. Knight gives us, in fascinating contrast, Davy’s first, breathless, almost inarticulate account of his discoveries in his lab notebook, and the famous later account known to every schoolboy of my generation: When the current flowed “a most intense light was exhibited at the negative wire, and a column of flame…arose from the point of contact.” This produced shining metallic globules, indistinguishable in appearance from mercury—globules of a new element, metallic potassium. “The globules often burnt at the moment of their formation, and sometimes violently exploded and separated into smaller globules, which flew with great velocity through the air in a state of vivid combustion, producing a beautiful effect of continued jets of fire.”6 When this occurred, Davy, his cousin Edmund records, danced with joy around the lab.

My own greatest delight, as a boy, was to repeat Davy’s electrolytic production of sodium and potassium, to see these shining globules catch fire of themselves, burning with a vivid yellow flame or a pale mauve one; and later, to obtain metallic rubidium (which burns with an enchanting ruby-red flame), an element not known to Davy, but which he would certainly have appreciated. I so identified with Davy’s original experiments that I could almost feel I was discovering these elements myself.

Soda” and “potash,” the alkalis, had been regarded as elements by Lavoisier, as had the alkaline earths—lime, magnesia, strontia, and baryta. Davy next turned to these, and within a few weeks had isolated their metallic elements too—calcium, magnesium, strontium, and barium—highly reactive metals, especially strontium and barium, able to burn, like the alkali metals, with brilliantly colored flames. And if the isolation of six new, unprecedentedly reactive metallic elements in a single year was not enough, Davy isolated yet another element, boron, the following year.

Elemental sodium and potassium do not exist in nature; they are too reactive and will instantly combine with other elements. What one finds, instead, are neutral salts—sodium chloride (common salt), for example—which are chemically inert and electrically neutral. But if one submits these, as Davy did, to a powerful electric current transmitted through two electrodes, the neutral salt can be decomposed, its intensely active and electrically charged particles (electropositive sodium, electronegative chloride, for example) being attracted toward either electrode. Faraday later named these particles “ions.”

For Davy, electrolysis was not only “a new path of discovery,” which incited him to request ever larger and more powerful batteries for his use—the beginnings of “big science,” in 1808. It was also a revelation that matter itself was not something inert, as had been thought by Newton and hitherto, but was charged and held together by electrical forces.

Chemical affinity and electrical force, Davy now realized, determined each other, and were one and the same in the constitution of matter. Boyle and his successors, including Lavoisier, had no clear idea about the fundamental nature of chemical bonds. They were assumed up to Davy’s time to be gravitational; Davy could now envisage another universal force, electrical in nature, holding together the very molecules of matter itself, and beyond this, had a cloudy but intense vision that the entire cosmos was pervaded by electrical forces as well as gravitation.

In 1810, Davy reexamined Scheele’s heavy greenish gas, previously seen by Scheele and Lavoisier as compound in nature, and was able to show that it was an element. He named it, in view of its color (chloros, greenish yellow), chlorine. He now realized that it was not only a new element, but a representative of a new chemical family—a family of elements, like the alkali metals, too active to exist in nature but of the most distinctive kind. Davy felt sure there must be heavier and lighter analogs of chlorine, members of the same family.7

These years from 1806 to 1810 were the most creative years of Davy’s life, both in his empirical discoveries and in the profound concepts arising from them. He had discovered eight new elements. He had overturned the last traces of the phlogiston theory and Lavoisier’s notion that atoms were merely metaphysical entities. He had shown the electrical basis of chemical reactivity. He had grounded chemistry, and transformed it, in these five intense years.

Davy’s electrochemical researches, and his vision of the electrochemical structure of matter, made him; for many of his countrymen, “the Newton of chemistry.” If he enjoyed the highest esteem from his colleagues, winning many scientific honors at this time, he enjoyed an equal fame with the educated public through his popularizations of science. He loved to conduct experiments in public, and his famous lectures, or lecture-demonstrations, were exciting, eloquent, highly dramatic, and, sometimes literally, explosive. Davy, moreover, seemed in his own person to be at the crest of a vast new wave of scientific and technological power, a power that promised, or threatened, to transform the world. What honor could the nation bestow on such a man? There seemed only one, though it was almost without precedent. On April 8, 1812, Davy was knighted by the prince regent, the first scientist8 to be so elevated since Newton in 1705.

  1. 4

    An enthralled responder to Davy’s inaugural lecture was Mary Shelley. Years later, in Frankenstein, she was to model Professor Waldman’s lecture on chemistry rather closely on some of Davy’s words when, speaking of galvanic electricity, he said, “a new influence has been discovered, which has enabled man to produce from combinations of dead matter effects which were formerly occasioned only by animal organs.”

  2. 5

    Coleridge was not the only poet to renew his stock of metaphors with images from chemistry. The chemical phrase “elective affinities” was given an erotic connotation by Goethe; “energy” became, for Blake, “eternal delight”; Keats, trained in medicine, reveled in chemical metaphors. Eliot, in “Tradition and the Individual Talent,” employs chemical metaphors from beginning to end, culminating in a grand, “Davyan” metaphor for the poet’s mind: “The analogy is that of the catalyst… The mind of the poet is the shred of platinum.” One wonders whether Eliot knew that his central metaphor, catalysis, was discovered by Humphry Davy in 1816. A wonderful metaphoric use of chemistry is Primo Levi’s novel, The Periodic Table. Levi himself, of course, was both a chemist and a writer.

  3. 6

    Davy was so startled by the inflammability of sodium and potassium, and their ability to float on water, that he wondered whether there might not be deposits of these beneath the earth’s crust, which, exploding upon the impact of water, were responsible for volcanic eruptions.

  4. 7

    Thinking in analogies has both strengths and dangers. Davy was convinced that there was a lighter analog of chlorine, and that it was contained in hydrofluoric acid. He was indeed correct here, but fluorine is so active—it is the most active element known—that it attacked even an electrode of platinum, converting it into platinum fluoride, so that Davy was never able to obtain the pure gas. He was equally sure there should be a lighter analog of sodium, and here he was more fortunate—he obtained this new element (lithium) in 1818. Ammonium salts being so similar to sodium salts, Davy felt there should also be a metal—”ammonium”—analogous to sodium; and he was indeed able to produce a strange ammonium amalgam similar in properties to sodium amalgam. But his efforts to isolate the “ammonium” were all in vain—it vanished before his eyes, decomposing, leaving nothing behind.

  5. 8

    The term “scientist” did not exist until Whewell devised it in 1834.

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