The Age of Wonder (51 page)

Nowhere in this bleak and heartfelt letter, written to another Bristol friend, his erstwhile laboratory assistant Clayfield, did Davy mention God, or any conventional notion of heaven. Instead, he tried to tell himself that there was some incomprehensible ‘arrangement’ by which Watt’s unfulfilled gifts would be ‘applied’ by Nature. He drew on a familiar analogy with the transformation of the butterfly, but even this took him in an odd and unexpected philosophical direction: ‘The caterpillar, in being converted into an inert scaly mass, does not appear to be fitting itself for an inhabitant of air, and can have no consciousness of the brilliancy of its future being. We are masters of the earth, but perhaps we are the slaves of some great and unknown beings…We suppose that we are acquainted with matter, and with all its elements, and yet we cannot even guess at the cause of electricity, or explain the law of the formation of the stones which fall from meteors. There may be beings-thinking beings, near us, surrounding us, which we do not perceive which we can never imagine. We know very little; but, in my opinion, we know enough to hope for the immortality, the
individual immortality of the better part of man.
’
¹⁵⁸

This was the nearest Davy would come to any idea of the soul, or personal immortality. But what is surprising is his notion of mankind, the ‘masters of the earth’, being themselves subject to other and greater masters, alien powers elsewhere in the universe. He did not conceive of these as gods, but more like the extraterrestrial intelligences of science fiction, ‘thinking beings’, close by, but invisible, imperceptible, even unimaginable. He would return to this idea in the last book he ever wrote,
Consolations in Travel.

In 1805 Davy branched out and gave his spring lectures at the Royal Institution ‘On Geology’. For this he had read the work of Hutton and Playfair, and grappled with the new controversies about the age of the earth, and whether its rocks were formed by flood or by volcanic action. His demonstrations included a large-scale model of a volcano, mounted on an insulated plate, that innocently emitted smoke, then suddenly burst into flames, and finally erupted in a cloud of ‘ash’. He also recalled his expeditions in Cornwall with Gregory Watt, and delivered a heartfelt elegy on this early, lost friend.
¹⁵⁹

Davy spent a relaxed summer in the Lake District, and climbed Helvellyn with Wordsworth, Southey and Walter Scott. They talked of Coleridge, who was still absent somewhere in the Mediterranean, and writing home ever less frequently. Davy hoped nonetheless that ‘his genius will call forth some new creations, and that he may bring back to us some garlands of never-dying verse’. He wrote to Coleridge, urging him to return to England and give a course of lectures on Poetry at the Royal Institution.

Davy returned to London to be awarded the Copley Medal by Banks (for some humdrum work on agricultural chemistry), and elected to the Council of the Royal Society. He was also invited to give the important annual series of Bakerian Lectures at the Royal Society, starting the following autumn. There seemed nothing that could now stop his career, and his meteoric rise to fame at the age of twenty-six. But he still needed to achieve a major scientific discovery to secure his name. In October his early hero Horatio Nelson, whose victory at the Nile he always associated with his professional beginnings in science, was killed at the battle of Trafalgar.

11

On 20 November 1806 Humphry Davy gave his first Bakerian Lecture, to a packed theatre at the Royal Society, with Joseph Banks presiding in the chair. It was a prestigious but challenging appointment. The series had been founded in 1775 by Daniel Defoe’s son-in-law, Henry Baker, and dedicated to advances in ‘Experimental Philosophy’. Some genuinely new discovery had to be demonstrated, and Davy was expected to choose as his subject either gases, or geology, or agricultural chemistry. Instead he announced that he would be ‘investigating and elucidating’ the nature of electricity, the use of the new voltaic battery, and the possibilities of opening up a wholly new field of ‘electro-chemical analysis’. The lecture created an international sensation. It would be followed by four more over the next four years: the second Bakerian on 19 November 1807, the third on 15 December 1808, the fourth on 15 November 1809, and the fifth and last on 15 November 1810.
¹⁶⁰

Davy began his first lecture with a characteristically enticing
tour d’horizon:
‘It will be seen that Volta has presented to us a key which promises to lay open some of the most mysterious recesses of nature. Till this discovery, our means were limited; the field of pneumatic research had been exhausted, and little remained for the experimentalist except minute and laborious processes.
There is now before us a boundless prospect of novelty in science; a country unexplored, but noble and fertile in aspect; a land of promise in philosophy.
’
¹⁶¹

He first set out to clarify the nature of electricity, which was still not remotely understood. It was popularly regarded as an invisible and volatile fluid stored in glass Leyden jars, ever ready to leap out with a bang. Against all appearances, Davy argued, the electrical charge stored in Leyden jars or produced by voltaic batteries was no different in kind from that produced by a stormcloud, a ‘torpedo’ or electric eel, or a handcranked friction generator, except that it was more manageable and sustained. Moreover, it was energy produced by
chemical
changes. The tingle produced by acid saliva on a metal tooth filling is just such a chemical change. ‘A plate of zinc and a plate of silver, brought into contact with each other, and applied to the tongue, produce a strong caustic sensation. This is analogous with…the experiment of Galvani, on the excitation of the muscles of animals.’
¹⁶²

Next, he demonstrated that electricity did not itself ‘generate’ matter, as most of his contemporaries thought, but was a form of pure energy. It was, he argued, essentially
bi-polar
energy, divided into a negative charge (associated with heating and expansion) and a positive charge (associated with cooling and contraction). Lightning, for example, was generated by negatively charged stormclouds meeting positively charged ones.
¹⁶³
(Modern physics would explain lightning as caused by a massive discharge of static electricity, generated by agitated electrons within a single stormcloud.)

Davy then set out a meticulous series of experiments, using a number of different salts and alkalis, which proved that there was such a thing as ‘chemical affinity’ throughout nature. That is, chemical materials were held together, or bonded, by the positive and negative energies of electricity. By using the voltaic battery as an analytical tool, and ‘decomposing’ various metals and earths by electrolysis (usually over several days), he promised to reveal entirely new elements, hitherto unknown and unnamed. These investigations ‘can hardly fail to enlighten our philosophical system of the earth; and may possibly place new powers in our reach’.
¹⁶⁴

Throughout, Davy referred confidently to scientific work going on across Europe, notably by Berzelius and Potin in Stockholm, and Gay-Lussac and Thénard in Paris. But he calmly explained that he had corrected, refined or overtaken all of their experiments. He was in effect claiming that British chemistry, for the first time since Hooke and Boyle in the seventeenth century, led the scientific world. This first Bakerian Lecture was both brilliant and challenging, but so far Davy had merely set out his stall. It was not until the revelations of the second Bakerian Lecture that he hoped the full, revolutionary impact of his work would be recognised.

In the interim, Davy spent much of the summer of 1807 either fly-fishing or trying to persuade Coleridge to undertake a series of literary lectures at the Royal Institution. These turned out to be very similar pursuits. Coleridge had returned from Malta inspired and refreshed by his experiences (among other things, he had fallen in love with a Sicilian
prima donna
), but more hopelessly addicted to opium than ever. Aware of his fragile state, Davy wrote briskly to their mutual friend Tom Poole: ‘In the present condition of society, his opinions in matters of taste, literature and metaphysics must have a healthy influence.’

Davy was also optimistic about the state of the war against France. ‘Buonaparte seems to have abandoned the idea of invasion, and if our government is active, we have little to dread from a maritime war…The wealth of our island may be diminished, but the strength of the people cannot easily pass away; and our literature, our science, and our arts, and the dignity of our nature, depend little upon external relations. When we had fewer colonies than Genoa, we had Bacons and Shakespeares.’ In fact, for Davy, science was becoming increasingly patriotic.
¹⁶⁵

On 19 November 1807 Davy gave his second Bakerian Lecture at the Royal Society. He dramatically described how he had just isolated two wholly new elements, potassium and sodium, by ‘electrolysis’. By ingenious use of the Institution’s voltaic batteries he had over several hours charged and decomposed the common alkalis soda and potash in a vacuum flask, and found the unknown chemicals forming in a crust at the positive and negative poles of the battery. When he extracted the globules of potassium from the crust of potash, they burst spontaneously into an astonishing, bright lilac-coloured flame. Sodium reacted similarly when plunged into water, producing an equally vivid orange flame. Here matter itself seemed to be breaking into life from a previously secret and hidden world, at the chemist’s sole command.

Davy had left these experiments perilously late, only a few weeks before the second Bakerian Lecture was due. Almost deliberately, like a journalist working to a deadline, he put himself under extraordinary pressure, and had to work with hectic speed. But that was what he liked. On 6 October 1807 his laboratory notebook records in huge, triumphant letters: ‘CAPITAL EXPERIMENT PROVING THE DECOMPOSITION OF POTASH’.

The description of this historic discovery is given dramatically enough in Davy’s final lecture text: ‘The potash began to fuse at both its points of electrization. There was a violent effervescence at the upper [positive] surface; and at the lower, or negative surface, there was no liberation of elastic fluid; but small globules having a high metallic lustre, and being precisely similar in visible characters to quick silver, appeared, some of which burnt with explosion and bright flame…These globules, numerous experiments soon showed to be the substance I was in search of.’
¹⁶⁶

But Davy’s real excitement and relief is only revealed in his assistant’s account of that day. The twenty-eight-year-old Professor of Chemistry became a schoolboy again. ‘When he saw the minute globules of potassium burst through the crust of potash, and take fire as they entered the atmosphere, he could not contain his joy-he actually danced about the room in ecstatic delight; some little time was required for him to compose himself to continue the experiment.’
¹⁶⁷
Davy had discovered the principle of ‘electro-chemical’ analysis, a term that he coined, and opened up the vast field for experiment that he had promised.
^♣

The lectures were greeted with universal excitement and praise. Banks was deeply impressed. When he had his official portrait painted in the Royal Society’s presidential chair the following year, wearing all his insignias and honours, he was shown holding a transcript of Davy’s Bakerian Lectures. In Bristol, his old patron Beddoes recorded proudly: ‘Davy has just solved one of the greatest problems in chemistry by decomposing the fixed alkalis.’
¹⁶⁸
The newly founded
Edinburgh Review
ran a series of long articles on the Bakerian Lectures, written by its rising young intellectual star Henry Brougham.
¹⁶⁹
Coleridge wrote to praise Davy’s ‘march of glory’.
¹⁷⁰

Even Davy’s acknowledged rivals saluted him. The renowned Scandinavian chemist Jacob Berzelius described it as one of the finest of all modern chemical experiments. The French Académie des Sciences, partly through the good offices of Gay-Lussac, awarded Davy the new Prix Napoléon, worth the enormous sum of 60,000 francs. The Académie issued a formal invitation that Davy come to Paris to collect it. It was a fine and challenging gesture at a time of bitter war between the two nations, but diplomatically there were difficulties from the start. Davy assumed he had won the total sum donated by Napoleon, but the actual prize consisted of the annual interest from that capital, a rather more modest 3,000 francs.
¹⁷¹

For all his success, Davy was overworked and exhausted. Immediately after his lecture he had undertaken to oversee a ventilation scheme for Newgate Prison, and he fell dangerously ill with a form of jail fever in December 1807. He was near death for several weeks, and an invalid for several months. His patient physician, Dr Thomas Babington, a fellow fly-fisherman, became a friend for life. He did not return to his laboratory until 19 April 1808.

This brush with death at the age of twenty-nine only increased Davy’s celebrity, and raised his reputation in scientific circles. The Royal Institution issued daily public reports about his health, and gave a special lecture examining the significance of his work and comparing him to Bacon, Boyle and Cavendish. It also voted funds for a huge new voltaic battery to be constructed for his future use, a trough of ‘600 double plates of four inches square’, said to be four times as powerful as any in England. The following year, after the fourth Bakerian Lecture, a private subscription provided a 2,000-plate battery, now said patriotically to be more powerful than any in Europe-including, of course, France.
¹⁷²