June 24, 2004
"Wilt thou sit down whilst I put this lad right about his arithmetic?"

I've already quoted here from the delightful A Short History of Nearly Everything, about the American scientist Michelson. Here is Bill Bryson describing that modest genius of chemistry, John Dalton (1766-1844). Dalton was a school-teacher from a very early age, until – despite his scientific eminence – a very late one.

Dalton.jpgDalton was born in 1766 on the edge of the Lake District, near Cockermouth, to a family of poor and devout Quaker weavers. (Four years later the poet William Wordsworth would also join the world at Cockermouth.) He was an exceptionally bright student – so very bright, indeed, that at the improbably youthful age of twelve he was put in charge of the local Quaker school. This perhaps says as much about the school as about Dalton's precocity, but perhaps not: we know from his diaries that at about this time he was reading Newton's Principia – in the original Latin – and other works of a similarly challenging nature. At fifteen, still school-mastering, he took a job in the nearby town of Kendal, and a decade after that he moved to Manchester, whence he scarcely stirred for the remaining fifty years of his life. In Manchester he became something of an intellectual whirlwind, producing books and papers on subjects ranging from meteorology to grammar. Colour blindness, a condition from which he suffered, was for a long time called Daltonism because of his studies. But it was a plump book called A New System of Chemical Philosophy, published in 1808, that established his reputation.

There, in a short chapter of just five pages (out of the book's more than nine hundred), people of learning first encountered atoms in something approaching their modem conception. Dalton's simple insight was that at the root of all matter are exceedingly tiny, irreducible particles. 'We might as well attempt to introduce a new planet into the solar system or annihilate one already in existence, as to create or destroy a particle of hydrogen,' he wrote.

Neither the idea of atoms nor the term itself was exactly new. Both had been developed by the ancient Greeks. Dalton's contribution was to consider the relative sizes and characters of these atoms and how they fit together. He knew, for instance, that hydrogen was the lightest element, so he gave it an atomic weight of 1. He believed also that water consisted of seven parts of oxygen to one of hydrogen, and so he gave oxygen an atomic weight of 7. By such means was he able to arrive at the relative weights of the known elements. He wasn't always terribly accurate – oxygen's atomic weight is actually 16, not 7 – but the principle was sound and formed the basis for all of modern chemistry and much of the rest of modem science.

The work made Dalton famous – albeit in a low-key, English Quaker sort of way. In 1826, the French chemist P. J. Pelletier travelled to Manchester to meet the atomic hero. Pelleder expected to find him attached to some grand institution, so he was astounded to discover him teaching elementary arithmetic to boys in a small school on a back street. According to the scientific historian E. J. Holmyard, a confused Pelletier, upon beholding the great man, stammered:


'Est-ce que j'ai I'honneur de m'addresser a Monsieur Dalton?' for he could hardly believe his eyes that this was the chemist of European fame, teaching a boy his first four rules. 'Yes,' said the matter-of-fact Quaker 'Wilt thou sit down whilst I put this lad right about his arithmetic?'


Although Dalton tried to avoid all honours, he was elected to the Royal Society against his wishes, showered with medals and given a handsome government pension. When he died in 1844, forty thousand people viewed the coffin and the funeral cortege stretched for two miles. His entry in the Dictionary of National Biography is one of the longest, rivalled in length among nineteenth-century men of science only by those of Darwin and Lyell.

Posted by Brian Micklethwait at 10:37 PM
Category: Famous educationsScience