III. CHEMISTRY: DALTON AND DAVY

In that same decade, and also at the Royal Institution, John Dalton revolutionized chemistry with his atomic theory (1804). Son of a Quaker weaver, he was born (1766) at Eaglesfield, near Cockermouth, at the northern end of that misty magnificent Lake District which was soon to harbor Wordsworth, Coleridge, and Southey. Later, writing in the third person, he summarized his early career in a bald chronology that does not quite hide the hot ambition that burns a path to accomplishment:

The writer of this… attended the village school… till 11 years of age, at which period he had gone through a course of Mensuration, Surveying, Navigation, etc.; began about 12 to teach the village school;… was occasionally employed in husbandry for a year or more; removed to Kendal at 15 years of age as assistant in a boarding school, remained in that capacity for 3 or 4 years, then undertook the same school as a principal, and continued for 8 years, and while at Kendal employed his leisure in studying Latin, Greek, French, and the Mathematics with Natural Philosophy, removed thence to Manchester in 1793 as Tutor in Mathematics and Natural Philosophy in the New College.4

Whenever time and funds permitted he carried on observations and experiments, despite color blindness and crude instruments, many of them made by himself. Amid his many interests he found time to keep a meteorological record from his twenty-first year to a day before his death.5 His vacations were usually spent foraging for facts in those same mountains where Wordsworth would roam a few years later; however, while Wordsworth was looking and listening for God, Dalton was, for example, measuring atmospheric conditions at different altitudes—much as Pascal had done a century and a half before.

In his experiments he accepted the theory of Leucippus (c. 450 B.C.) and Democritus (c. 400 B.C.) that all matter consists of indivisible atoms; and he proceeded on the assumption of Robert Boyle (1627–91) that all atoms belong to one or another of certain ultimate indecomposable elements—hydrogen, oxygen, calcium… In A New System of Chemical Philosophy (1808) Dalton argued that the weight of any atom of an element, as compared with any atom of another element, must be the same as the weight of a mass of the first element as compared with an equal mass of the other. Taking the weight of a hydrogen atom as one, Dalton, after many experiments and calculations, ranged each of the other elements by the relative weight of any one of its atoms with an atom of hydrogen; and so he drew up, for the thirty elements known to him, a table of their atomic weights. In 1967 chemists recognized ninety-six elements. Dalton’s conclusions had to be corrected by later research, but they—and his complex “law of multiple proportions” in all combinations of elements—proved of immense help in the progress of the science in the nineteenth century.

More varied and exciting were the life, education, and discoveries of Sir Humphry Davy. Born in Penzance (1778) of a well-to-do middle-class family, he received a good education, and supplemented it with expeditions that combined geology, fishing, sketching, and poetry. His happy nature won him a miscellany of friends, from Coleridge, Southey, and Dr. Peter Roget—the ingenious and indefatigable compiler of the Thesaurus of English Words and Phrases (1852)—to Napoleon. Another friend allowed him free use of a chemical laboratory, whose bubbling retorts charmed Davy into dedication. He organized his own laboratory, sampled diverse gases by inhaling them, persuaded Coleridge and Southey to join his inhaling squad, and almost killed himself by breathing water gas, a powerful poison.

At the age of twenty-two he published an account of his experiments as Researches Chemical and Philosophical (1800). Invited to London by Count Rumford and Joseph Banks, he gave lectures and demonstrations on the wonders of the storage battery (Volta’s “pile”), bringing new fame to the Royal Institution. Using a battery of 250 pairs of metal plates as an agent of electrolysis, he decomposed various substances into their elements; so he discovered and isolated sodium and potassium; soon he went on to isolate barium, boron, strontium, calcium, and magnesium, and add them to the list of elements. His achievements established electrochemistry as a science endless in its theoretical and practical possibilities. The news of his work reached Napoleon, who sent him in 1806, across the frontiers of war, a prize awarded by the Institut National. Berthollet in 1786 had explained to James Watt the bleaching power of chlorine; England had been slow to use the suggestion; Davy renewed it effectively. In him science and industry developed that mutual stimulation which was to play a leading role in the economic transformation of Great Britain.

In 1810, before an audience at the Royal Institution, Davy performed experiments demonstrating the power of an electric current, in passing from one carbon filament to another, to produce both light and heat. He described the operation:

When pieces of charcoal about an inch long and one-sixth of an inch in diameter were brought near each other (within the thirtieth or fortieth of an inch), a bright spark was produced, and more than half the volume of the charcoal became ignited to whiteness; and, by withdrawing the points from each other, a constant discharge took place through the heated air, in a space equal to at least four inches, producing a most brilliant ascending arch of light…. When any substance was introduced into this arch, it instantly became ignited; platina melted as readily in it as wax in a common candle; quartz, the sapphire, magnesia, lime, all entered into fusion.6

The potentialities of this process of generating light and heat were not developed until cheaper ways of producing electric current were invented; but in that brilliant experiment lay the electric blast furnace, and the transformation of night into day for half the population of the earth.

In 1813, accompanied by his young assistant Michael Faraday, and armed with a safe-conduct issued by Napoleon while nearly all Europe was at war, Davy traveled through France and Italy, visiting laboratories, making experiments, exploring the properties of iodine, and proving that the diamond is a form of carbon. Returning to England, he studied the causes of mine explosions, and invented a safety lamp for miners. In 1818 the Prince Regent made him a baronet. In 1820 he succeeded Banks as president of the Royal Society. In 1827, his health having begun to fail, he gave up science for fishing, and wrote a book thereon, illuminated by his own drawings. In 1829, partly paralyzed, he went to Rome to be “a ruin amongst ruins,”7 but he died before the year was out. He had been allowed only fifty-one years, but he had crowded many lives into that half century. He was a good great man and one of those redeeming men and women who must be weighed in the balance against our ignorance and sins.

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