Grease and salt

This week New York is covered in a thin layer of grease. Yeah no, it isn't normally yuk yuk. It's especially apparent underground, on the tile floor of the subway platforms (danger), but if you pay attention you can detect it on the sidewalks too. It varies somewhat from neighbourhood to neighbourhood. In fact, in some places it feels simultaneously slick and tacky. Maybe it has to do with the salt that was put down after the snowstorm - I don't remember this stuff before Monday.