Some of the fun stuff done while the school was open was hepatitis A human experimentation. Kids were inoculated with Hep A virus directly and monitored.
The 2009 documentary Cropsy is based around an urban legend (turned somewhere true) of an escaped mental patient who lived in the ruins of this hospital http://cropseylegend.com/ - there's a lot of footage of the hospital itself and surrounding areas. A pretty creepy place, even in the daytime.