the coffee and tea contribution to the

industrial revolution
It's hardly a coincidence that coffee and tea caught on in Europe just as the first factories were ushering in the industrial revolution. The widespread use of caffeinated drinks—replacing the ubiquitous beer—facilitated the great transformation of human economic endeavor from the farm to the factory. Boiling water to make coffee or tea helped decrease the incidence of disease among workers in crowded cities. And the caffeine in their systems kept them from falling asleep over the machinery. In a sense, caffeine is the drug that made the modern world possible. And the more modern our world gets, the more we seem to need it. Without that useful jolt of coffee—or Diet Coke or Red Bull—to get us out of bed and back to work, the 24-hour society of the developed world couldn't exist.
Scientists have developed various theories to explain caffeine's "wake-promoting" power. The consensus today focuses on the drug's interference with adenosine, a chemical in the body that acts as a natural sleeping pill. Caffeine blocks the hypnotic effect of adenosine and keeps us from falling asleep. Since caffeine has also been shown to enhance mood and increase alertness in moderate amounts, it's a potent potion for students and scholars stuck in the lab at three in the morning. Paul Erdos, the Hungarian mathematician who often worked his equations around the clock, is known for saying that "a mathematician is a machine for turning coffee into theorems."
The principal reason that caffeine is used around the world is to promote wakefulness.But the principal reason that people need that crutch is inadequate sleep. Think about that: We use caffeine to make up for a sleep deficit that is largely the result of using caffeine.


from a national geographic article