Martin Couney ran a Coney Island sideshow. Visitors paid 25 cents to watch premature babies living in incubators. Hospitals were turning preemies away as weaklings. Couney's exhibit gave them state-of-the-art care for free. Parents paid nothing. Over 40 years, roughly 6,500 of the 8,000 babies in his care went home. He wasn't even a licensed doctor.