It's always amazing to learn what kinds of things passed as medicine before - and even during - the birth of modern science. In colonial times, for example, American medicine used such "cures" as the moss from a dead man's skull - thankfully, though, the moss was applied, not to the wound, but to the weapon that caused it. And as recently as the beginning of the twentieth century, we have evidence of alcohol being prescribed to reduce asthma attacks.

One cure that may not have worked much better - but was probably a whole lot more fun to those prescribed it - is tobacco. Most of us are not used to having our doctors prescribe us a cigar, to put it mildly. But before twentieth-century methods of epidemiological study were developed, tobacco was not only often treated as medically harmless, it was intermittently recommended or even prescribed for its medicinal value.

For an example of just how much attitudes have changed, let's pause for a moment over the figure of Jean Nicot - the Frenchman for whom nicotine was named, and who was also the first to bring the smoking of tobacco to French high society. European pleasure-smokers owe Nicot a considerable debt. Without him, Jean-Paul Sartre would never have smoked a single Gauloise, and the coffeehouse poets and existentialists of the twentieth century would have had to do something else with their hands when they weren't gesturing wildly at each other. Jean-Paul Belmondo, the iconic smoking hero of the classic French New Wave film Breathless, would never have looked half as cool if it weren't been for Jean Nicot. And yet Nicot recommended smoking tobacco not for its cosmetic and dramatic value, nor for its taste - he recommended it as a medicine!

As the French ambassador to the Portuguese court, Nicot observed Portuguese nationals enjoying the new all-purpose medical remedy that had come to that country earlier in the sixteenth century, in all likelihood from Spain, who had in turn stolen the idea from the native inhabitants of South America, the "New World." After all, the rolling and smoking of tobacco in a tube-shaped receptacle was almost the first thing that Columbus had learned from the indigenous peoples of the Americas. Two members of his first expedition noticed the custom during an inland journey through modern-day Cuba on November 6, 1492.

And when smoking made the jump from Cuba to Spain, it then spread throughout Europe, riding the coattails of - believe it or not - its supposed medicinal value, setting a pattern that several other commodities introduced to Europe via colonialism would follow: tea, coffee, certain kinds of alcohol, and others were also initially lauded for their health benefits.

It was in Shakespeare's England that smoking first became broadly popular - the 1580s and 1590s. In 1577 a Spanish treatise by Nicolas Monardes was rendered into English. This work, exuberantly titled Joyfull Newes out of the new founde worlde, told English readers about a wonderful new import from the Americas, tobacco, which could reduce or alleviate the symptoms of another thing then new to England: syphilis.

After Monardes, the idea became a sort of commonplace. Giles Everard thought tobacco might be, literally, a cure-all. Much of this enthusiasm came from the dominant medieval medical theory: the idea of the humors. According to this doctrine, received from the ancient Greeks, there were four elements whose balance or imbalance among each other determined the body's health: dryness, heat, wetness, and coldness. You had to keep them in balance. It was thought, then, that smoking could help "dry out" individuals suffering from a dominance of the cool and wet humors (which made the body weak and effeminate).

People also thought, in advance of tobacco's arrival in England, that breathing in smoke - in and of itself - was good for you. Patients in early modern England would breathe in smoke from cinnabar and amber, among many other chemicals. People even breathed in the fumes from red arsenic. Smoke from all sorts of things efficiently delivered good-for-you chemicals to sick patients, so why not tobacco?

Eventually, this medical consensus in favor of tobacco was undone - partly because of the advance of medical science, but also for reasons that had nothing to do with science. As tobacco went from being an elite pleasure to one affordable by regular folks - the "masses" that European political thought always viewed with suspicion and disdain - it became correspondingly less, shall we say, cool. By the early seventeenth century, King James I and other influential polemicists were blaming it for making Britons lazy, pleasure-seeking, and unable to work. Tobacco's prestige has vacillated ever since.