Gotta love Chemistry

So one morning this last week I was preparing chemicals to do a lab with my students. Not a big deal right?
After school I looked at my hands. My right hand had brown stuff covering half of my palm. It looked like I had smeared chocolate all over. My left hand had small brown spots, and a couple of my fingernails were also brown.
I figured it must have been the chemicals. One of them I mixed up was silver nitrate which is used in film developing. It changes from clear to dark brown/black when it gets in the light. I must have spilled it on my hands and not noticed until later in the day after it got exposed.
I should have taken a picture. The color lasted about 24 hours, but my fingernails are still brown. Oh, the joys of teaching chemistry.