The act appears to be concerned about the marketing of opiates. However, a clause applying to doctors allowed distribution "in the course of his professional practice only." This clause was interpreted after 1917 to mean that a doctor could not prescribe opiates to an addict, since addiction was not considered a disease. A number of doctors were arrested and some were imprisoned. The medical profession quickly learned not to supply opiates to addicts. In "United States v. Doremus", 249 U.S. 86 (1919), the Supreme Court ruled that the Harrison Act was constitutional, and in "Webb v. United States", 249 U.S. 96, 99 (1919) that physicians could not prescribe narcotics solely for maintenance.