John Snow

1813-1858

English Physician, Epidemiologist and Anesthetist

John Snow correctly concluded that cholera was transmitted through the ingestion of contaminated water. Snow came to this conclusion by conducting several epidemiological studies in London, England. He also is known as the father of the science of anesthesiology.

Snow rose to prominence from rather humble beginnings as a farmer's son. He was born in York, England, in 1813, attended local schools, and served as an apprentice to a surgeon. This informal training led him to work as a surgeon's assistant until 1836 when he moved to London in order to pursue the formal study of medicine at the Windmill Street School of Medicine and the Westminster Hospital. Snow was a member of the Westminster Medical Society and gave speeches on typhus, alcoholism, and respiration at the club's meetings. He also was interested in the study of toxicology, or the science of poisons and their effects on living organisms. Throughout his life, Snow advocated vegetarianism and temperance (abstinence from alcohol), two movements that had adherents in both the United States and England in the first half of the nineteenth century.

Snow's fame rests on his study of cholera, a communicable and highly fatal disease that wreaks havoc on the gastrointestinal tract. Its symptoms include dehydration, paleness, and diarrhea. The disease is transmitted by ingesting food or water contaminated with the cholera bacillus. Although Snow was unaware of the existence of this microorganism (known by scientists as Vibrio cholerae and only discovered in 1884), he surmised that men and women contracted the disease by drinking infected water. His colleagues incorrectly believed that the disease was a fever brought on by the rotting of vegetation. Snow published his findings in 1849 in a work entitled On the Mode of Communication of Cholera. He examined the incidence, distribution, and communication of cholera in a number of London neighborhoods during the cholera epidemics that took place in England in the mid-nineteenth century. The main victims of the disease were the working and lower classes. Snow showed that infected water supplies spread the disease to the neighborhoods that used the water.

Snow's reputation as a scientist not only depended on his study of cholera but also on his investigation into the effects of chloroform and ether. He developed a fine reputation as an anesthetist as a result of his scientific experiments and his medical practice. Because of his knowledge of the subject and his experience, he was chosen to anesthetize Queen Victoria during the births of three of her children, Princes Arthur and Leopold and Princess Beatrice. The application of chloroform during childbirth became popular after Queen Victoria agreed to undergo the procedure. Consequently, the pains of labor and delivery were diminished for many women.

KAROL K. WEAVER