make wizard hats vulnerable to acid again

[mralexs]

Seemed to have worked fine during one of the syndie rounds I was in where a chemist just started hucking chem glasses at us. Lots of fire balls and shit.

iirc, they now drip some of their contents on the floor every tile they pass over.

How much acid is needed to melt things? I'm pretty sure even with the nerf they'd still have enough to melt a wiz hat