When I was at school, our science teacher had what he claimed was a human brain in jar. At the end of term, he'd let us all poke it with our fingers. I always thought it was a sad fate for some noble soul who had donated his body to science, only to end up with his brain rolling about in the hands of grubby fourteen year olds.

Nowdays, of course, you can just do this sort of stuff through the magic of the electronic interweb.....