The Enlightenment did not end barbarism and violence, Joel Mokyr laments, but it did end poverty in much of the world that embraced it:
In a few areas, useful knowledge turned out to be hugely productive. The rapidly growing cotton industry needed a chemical agent that could bleach fabrics, but traditional techniques were slow and expensive. In 1774, a Swedish chemist, Carl Wilhelm Scheele, discovered a substance that the Frenchman Claude Berthollet subsequently realized had miraculous bleaching properties. The recognition that this substance, later called chlorine, had industrial potential was a British idea. (Its other properties were discovered later: it began to be used as a disinfectant in the mid-nineteenth century, and the widespread chlorination of water began in the twentieth.)
Another example of the success of the Baconian program was in the field of lighting. Candles were expensive, emitted smoke, and often caused fires. Scientists all over enlightened Europe began to put their minds to the problem. In about 1780, Archibald Cochrane, the brilliant but eccentric earl of Dundonald, lit the coal gas above his tar ovens, mostly to amuse his friends; but we are not sure who first realized that the gas could not only burn well but also produce an immensely useful service. Claims for the breakthrough have been made for Jean-Pierre Minkelers, reputed to have lit his Leuven classroom with gas in 1784, and for Johann Georg Pickel, who certainly lit his German laboratory with gas in 1786. In 1799, the Frenchman Philippe Lebon took out a patent for a “thermolamp,” a glass device that would burn a combination of air and gas distilled from wood. After Lebon conducted a number of well-publicized demonstrations in Paris in 1801, it became abundantly clear that a radical new possibility had opened up. In 1807, some of Manchester’s cotton mills and the entire length of London’s Pall Mall were illuminated by coal gas in honor of King George’s birthday. In the following decade, gaslight turned night into day for many Europeans.
Optimism continued to abound about the potential of useful knowledge to improve the world. In 1780, one of the greatest figures of the Enlightenment, Benjamin Franklin, wrote in a letter that “the rapid progress true Science now makes, occasions my regretting sometimes that I was born so soon. It is impossible to imagine the Height to which may be carried, in a thousand years, the Power of Man over Matter…. O, that Moral Science were in as fair a way of Improvement.” He addressed that very Baconian sentiment to his friend Joseph Priestley, the British scientist and philosopher who invented soda water and discovered oxygen.