Uncertain or mistaken about the source of some diseases, citizens, doctors and health officials usually agreed that possible contagions should, at least, be quarantined and inspected. In the United States, mail has been treated in attempts to halt the spread of a number of deadly diseases, including yellow fever, smallpox, plague, typhus, cholera, diphtheria, measles, leprosy, scarlet fever, tuberculosis, influenza and even mumps. In some instances, mail was fumigated by sulphur fumes after having been punctured with a paddle such as this.

To contain a yellow fever epidemic in Florida in 1888, the Supervisory Surgeon General asked that all outgoing people, baggage and mail be subject to inspection. The Postmaster General agreed to fumigate all mail leaving the state. Letters were perforated with paddles, newspapers loosened, and the mail scattered on wire netting shelves in a railway mail car. After placing sulfur in iron kettles in the car and igniting it, employees closed up the mail car doors to let the fumes do their work.

Yellow fever outbreaks were common in the 19th century, and it was not until 1881 that doctors first considered the theory that yellow fever was transmitted by mosquito bites. A Cuban doctor, Carlos Finlay, was the first to present this hypothesis, which was finally verified in 1901. Although there is still no known treatment for yellow fever, Dr. Max Theiler developed a vaccine for the disease in 1939.

Written by Nancy A. Pope