A few readers let us know that they smelled the sickly sweet smell of a maple syrup-like substance last evening. Now, this brings back a flood of memories from 2005, when a maple syrup smell blanketed much of Manhattan.

The smell, which has made return visits in early December 2005 aJanuary 2006, March 2006 and November 2006, leading us to believe this is a cold weather phenomena. One reader noted that it was detected around Columbia University, but not around West 72nd Street, while another agreed it was on the Upper West Side but felt it actually smelled more like anti-freeze "which, if you ever
spilled while adding to your radiator, has a nasty maple syrup smell."

Did you smell it? And earlier this year, it smelled like mercaptan, a chemical used to make natural gas smell like, well, what we think of as natural gas.

Update, January 5, 2009: It's back in 2009—more details.