Sometime near the end of the lecture, Jerry turned off the room lights and turned on the UV lights and everyone learned an indelible and 'glowing' lesson in contamination and ease of transmission of materials -- infectious or chemical -- because we each 'lit up' in everywhere we had touched, scratched, etc.! because the pencil had been coated with fluorescein dye!!
This one 'trick' was such a great way to demonstrate this point.. never to be forgotten.
Jerry Abraham, MD (MIT '66)