pretty well irrefutable evidence that the Earth was at least many hundreds of millions of years old, probably rather more.

Remarkably, his evidence was based on alchemy-natural, spontaneous, scientifically credible, and wholly non-occult, but alchemy nonetheless. Newton, it turned out, had not been so wrong after all. And exactly how that came to be is of course another story.

7 ELEMENTAL MATTERS

CHEMISTRY AS AN earnest and respectable science is often said to date from 1661, when Robert Boyle of Oxford published The Sceptical Chymist-the first work to distinguish between chemists and alchemists-but it was a slow and often erratic transition. Into the eighteenth century scholars could feel oddly comfortable in both camps-like the German Johann Becher, who produced an unexceptionable work on mineralogy called Physica Subterranea, but who also was certain that, given the right materials, he could make himself invisible.

Perhaps nothing better typifies the strange and often accidental nature of chemical science in its early days than a discovery made by a German named Hennig Brand in 1675. Brand became convinced that gold could somehow be distilled from human urine. (The similarity of color seems to have been a factor in his conclusion.) He assembled fifty buckets of human urine, which he kept for months in his cellar. By various recondite processes, he converted the urine first into a noxious paste and then into a translucent waxy substance. None of it yielded gold, of course, but a strange and interesting thing did happen. After a time, the substance began to glow. Moreover, when exposed to air, it often spontaneously burst into flame.

The commercial potential for the stuff-which soon became known as phosphorus, from Greek and Latin roots meaning “light bearing”-was not lost on eager businesspeople, but the difficulties of manufacture made it too costly to exploit. An ounce of phosphorus retailed for six guineas-perhaps five hundred dollars in today’s money-or more than gold.

At first, soldiers were called on to provide the raw material, but such an arrangement was hardly conducive to industrial-scale production. In the 1750s a Swedish chemist named Karl (or Carl) Scheele devised a way to manufacture phosphorus in bulk without the slop or smell of urine. It was largely because of this mastery of phosphorus that Sweden became, and remains, a leading producer of matches.

Scheele was both an extraordinary and extraordinarily luckless fellow. A poor pharmacist with little in the way of advanced apparatus, he discovered eight elements-chlorine, fluorine, manganese, barium, molybdenum, tungsten, nitrogen, and oxygen-and got credit for none of them. In every case, his finds were either overlooked or made it into publication after someone else had made the same discovery independently. He also discovered many useful compounds, among them ammonia, glycerin, and tannic acid, and was the first to see the commercial potential of chlorine as a bleach-all breakthroughs that made other people extremely wealthy.

Scheele’s one notable shortcoming was a curious insistence on tasting a little of everything he worked with, including such notoriously disagreeable substances as mercury, prussic acid (another of his discoveries), and hydrocyanic acid-a compound so famously poisonous that 150 years later Erwin Schrodinger chose it as his toxin of choice in a famous thought experiment (see page 146). Scheele’s rashness eventually caught up with him. In 1786, aged just forty-three, he was found dead at his workbench surrounded by an array of toxic chemicals, any one of which could have accounted for the stunned and terminal look on his face.

Were the world just and Swedish-speaking, Scheele would have enjoyed universal acclaim. Instead credit has tended to lodge with more celebrated chemists, mostly from the English-speaking world. Scheele discovered oxygen in 1772, but for various heartbreakingly complicated reasons could not get his paper published in a timely manner. Instead credit went to Joseph Priestley, who discovered the same element independently, but latterly, in the summer of 1774. Even more remarkable was Scheele’s failure to receive credit for the discovery of chlorine. Nearly all textbooks still attribute chlorine’s discovery to Humphry Davy, who did indeed find it, but thirty-six years after Scheele had.

Although chemistry had come a long way in the century that separated Newton and Boyle from Scheele and Priestley and Henry Cavendish, it still had a long way to go. Right up to the closing years of the eighteenth century (and in Priestley’s case a little beyond) scientists everywhere searched for, and sometimes believed they had actually found, things that just weren’t there: vitiated airs, dephlogisticated marine acids, phloxes, calxes, terraqueous exhalations, and, above all, phlogiston, the substance that was thought to be the active agent in combustion. Somewhere in all this, it was thought, there also resided a mysterious elan vital, the force that brought inanimate objects to life. No one knew where this ethereal essence lay, but two things seemed probable: that you could enliven it with a jolt of electricity (a notion Mary Shelley exploited to full effect in her novel Frankenstein) and that it existed in some substances but not others, which is why we ended up with two branches of chemistry: organic (for those substances that were thought to have it) and inorganic (for those that did not).

Someone of insight was needed to thrust chemistry into the modern age, and it was the French who provided him. His name was Antoine-Laurent Lavoisier. Born in 1743, Lavoisier was a member of the minor nobility (his father had purchased a title for the family). In 1768, he bought a practicing share in a deeply despised institution called the Ferme Generale (or General Farm), which collected taxes and fees on behalf of the government. Although Lavoisier himself was by all accounts mild and fair-minded, the company he worked for was neither. For one thing, it did not tax the rich but only the poor, and then often arbitrarily. For Lavoisier, the appeal of the institution was that it provided him with the wealth to follow his principal devotion, science. At his peak, his personal earnings reached 150,000 livres a year-perhaps $20 million in today’s money.

Three years after embarking on this lucrative career path, he married the fourteen-year-old daughter of one of his bosses. The marriage was a meeting of hearts and minds both. Madame Lavoisier had an incisive intellect and soon was working productively alongside her husband. Despite the demands of his job and busy social life, they managed to put in five hours of science on most days-two in the early morning and three in the evening-as well as the whole of Sunday, which they called their jour de bonheur (day of happiness). Somehow Lavoisier also found the time to be commissioner of gunpowder, supervise the building of a wall around Paris to deter smugglers, help found the metric system, and coauthor the handbook Methode de Nomenclature Chimique, which became the bible for agreeing on the names of the elements.

As a leading member of the Academie Royale des Sciences, he was also required to take an informed and active interest in whatever was topical-hypnotism, prison reform, the respiration of insects, the water supply of Paris. It was in such a capacity in 1780 that Lavoisier made some dismissive remarks about a new theory of combustion that had been submitted to the academy by a hopeful young scientist. The theory was indeed wrong, but the scientist never forgave him. His name was Jean-Paul Marat.

The one thing Lavoisier never did was discover an element. At a time when it seemed as if almost anybody with a beaker, a flame, and some interesting powders could discover something new-and when, not incidentally, some two-thirds of the elements were yet to be found-Lavoisier failed to uncover a single one. It certainly wasn’t for want of beakers. Lavoisier had thirteen thousand of them in what was, to an almost preposterous degree, the finest private laboratory in existence.

Instead he took the discoveries of others and made sense of them. He threw out phlogiston and mephitic airs. He identified oxygen and hydrogen for what they were and gave them both their modern names. In short, he helped to bring rigor, clarity, and method to chemistry.

And his fancy equipment did in fact come in very handy. For years, he and Madame Lavoisier occupied themselves with extremely exacting studies requiring the finest measurements. They determined, for instance, that a rusting object doesn’t lose weight, as everyone had long assumed, but gains weight-an extraordinary discovery. Somehow as it rusted the object was attracting elemental particles from the air. It was the first realization that matter can be transformed but not eliminated. If you burned this book now, its matter would be changed to ash and smoke, but the net amount of stuff in the universe would be the same. This became known as the conservation of mass, and it was a revolutionary concept. Unfortunately, it coincided with another type of revolution-the French one-and for this one Lavoisier was entirely on the wrong side.

Добавить отзыв
ВСЕ ОТЗЫВЫ О КНИГЕ В ИЗБРАННОЕ

0

Вы можете отметить интересные вам фрагменты текста, которые будут доступны по уникальной ссылке в адресной строке браузера.

Отметить Добавить цитату
×