Dr. Leland's talk begins with a rather lengthy description of the history of cholera as chronicled by many ancient civilizations and the disease's pattern of epidemics, from its origin in India, through Asia to Europe and then America in the 19th century. He then analyzes these epidemic patterns, noting the variety of climates in which the disease exists, its tendency to follow rivers and shorelines, and its spread along commonly used global communication lines. He notes that winter cold halts its course. The onset of an epidemic is usually hailed by diseases such as yellow fever, dysentery, and influenza.
Leland describes the course of the disease in passengers on a trans-Atlantic ship bound for New York from England. He lists the various theories on the anatomical location in which cholera is based: the blood, the nervous system, or the intestinal tract. He outlines the debate over whether cholera is caused and spread by air, electricity, fungi, or other means. Dr. Leland presents evidence for the theory of contagion such as cholera's travel in caravans and ships along commercial routes which is limited by the speed of human travel, and the fact that initially it infects only a few victims, later expanding to epidemic proportions. Leland also offers the opposing argument that cholera is not contagious because it sometimes springs up in a community where no travelers could have brought it, it often lies dormant for years in a population only to suddenly affect the people once again, and it does not conform to traditional rules of "contagious diseases with regard to incubation longer or shorter, or inoculation from one to another." He believes one explanation for the disease's strange behavior is that cholera "possesses the power of multiplying or reproducing itself in the atmosphere; and is capable of being wafted through the air as well as carried a short distance, when of unusual intensity, by inanimate objects, such as the clothing of people affected."
Cholera is most fatal among the poor who live in cramped, dirty, insufficiently heated and cooled, unsanitary dwellings. It especially ravages the old, sick, malnourished, overworked, and alcoholics. The cities have a responsibility to drain cesspools, provide the impoverished with better living arrangements, and build hospitals for the victims of epidemics. "The public or private neglect of strict observance of proper sanitary or hygienic rules, while the pestilence is rife on its march will either promote or prevent the ravages of cholera." Medicines such as opium, capsicum, sugar of lead, and calomel are prescribed as a combination to "[act] on the nervous system as antispasmodic, sedatives, stimulants and astringents" to combat cholera.
Dr. Leland provides a complete account of cholera from its patterns of epidemic and contagion, to its manifestation, and finally to effective treatment methods.