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.
The disease is treatable with antibiotics which prevents most complications. Outcomes with scarlet fever are typically good. Long-term complications as a result of scarlet fever include: kidney disease, rheumatic heart disease, and arthritis. It was a leading cause of death in children in the early 20th century.