1600s: Medicine is in its infancy and still consists mostly of the use of herbs and other traditional medicines, many of which are more harmful than no treatment at all. No one knows that germs and viruses exist, and antibiotics, vaccines, and painkillers are unknown. People who are injured in duels, wars, or other combats often die from infections.

1800s: Although doctors still use bleeding, purging, and some dangerous substances that have no therapeutic value, they have discovered morphine, digitalis, and other drugs, as well as the importance of cleanliness in preventing disease.

Today: Medicine has rapidly advanced, with new treatments being invented every year. The most striking advance is the recent decoding of the entire human genome, which may allow treatment of previously incurable diseases.

1600s: King Louis XIII and Cardinal Richelieu consolidate royal power, decrease the power of the nobles, and begin...