This depends on the condition of the bill. In normal used condition, they are worth exactly $2. $2 bills dated 1976 and newer are the ones worth face value only. The $3/$4 figure is reasonable for bills dating back to the 1950s.
Klein thought he had, discovered the poison to be due to a disease of the cow. An epidemic of scarlet fever broke out in London in December, 1885, and the outbreak could be traced to the milk supplied by a herd in Hendon.
At the start of the twentieth century, the United States Army had a Yellow Fever Commission. The Army wanted medical experts to study yellow fever and find a way to stop the disease. One team went to Cuba to test the idea that mosquitoes spread yellow fever.The team was led by Walter Reed, the Army doctor and scientist noted for his work on infectious diseases.he was a nurse who worked with yellow fever patients in Cuba. Clara Maass was bitten by infected mosquitoes seven times between March and August of 1901. Only one of the nineteen people developed the disease -- until that August. Then seven people got yellow fever.