This thread is all about this mysterious compound. Perhaps it will become less mysterious with someones strange knowledge. Substance in question : those mouse pads, that have that pocket of jelly on one end, for wrist support. Of coarse this pocket is sealed in plastic. Surely someone else has in curiosity or boredom slit it open and [painstakingly] removed the compound, had some fun with it, and then regretted it. I did. I'm going to be mysterious and not speak of what happened right in this post. But does anyone know what that shit is called?

It depends on the manufacturer but this wiki details things all gels have in common, including links to specific gelling agents that should answer your question:

 

http://en.wikipedia.org/wiki/Gel