The most difficult history of medicine riddles

John Snow was an English physician and a leader in the adoption of anaesthesia and medical hygiene. He is considered one of the fathers of modern epidemiology, in part because of his work in tracing the source of a cholera outbreak in Soho, London, in 1854. His findings inspired fundamental changes in the water and waste systems of London, which led to similar changes in other cities, and a significant improvement in general public health around the world.

Tobacco was recognised by Europeans as a medicine soon after it was first imported from the New World, and tobacco smoke was used by western medical practitioners as a tool against cold and drowsiness. During the early 19th century the practice fell into decline, when it was discovered that the principal active agent in tobacco smoke, nicotine, is poisonous. A tobacco smoke enema was employed by the indigenous peoples of North America to stimulate respiration, injecting the smoke with a rectal tube

Syphilis was present in the Americas before European contact. It was carried from the Americas to Europe by the returning crewmen from Christopher Columbus's voyage. The first outbreak of syphilis in Europe occurred in 1494 in Naples, Italy, during a French invasion.