Chemical Changes when burning a dollar?

We did a lab in chemistry today. We put the dollar pill inside a beaker filled with alcohol and water. After a minute, we took the dollar out of the beaker and put it on the table, poured a little bit of the substance in the beaker, and tried to light it on fire. The water surrounding the dollar lit on fire, but the dollar didnt. Why does the water around a dollar bill burn and the dollar doesnt?