Dr. John Zahorsky was a St. Louis pediatrician, Professor of Pediatrics and Director of the Department of Pediatrics - St. Louis University School of Medicine, and author of several books including "Golden Rules of Pediatrics," "Synopsis of Pediatrics," "The Infant and Child in Health and Disease," and "From the Hills" (an autobiography). He is credited with the first clear clinical description of Roseola in 1909, which was (at one time) known as Zahorsky's Syndrome.
In 1904, he took over administration of the "Incubator Baby" exhibit at the St. Louis World's Fair, after it had come under criticism for an epidemic of diarrhea with several deaths, and wrote a series of articles about it which appeared in the St. Louis Courier of Medicine (linked below) and were later collected into a book titled "Baby Incubators, A Clinical Study Of The Premature Infant: With Especial Reference To Incubator Institutions Conducted For Show Purposes."
Dr. Zahorsky was born in 1871 in Mereny, Szepes, Hungary, and brought to the US as an infant. After 52 years of practicing pediatrics in St.Louis, he retired to his old home town of Steelville, Missouri, to practice as a country doctor. He died in 1963 at the age of 91.