Re: Old Wiring, New Lamp
Based on the age of your home and the description of the wires, you likely have old wiring that's insulated with rubber and covered with a cotton overbraid. Over time, this overbraid has discolored with age to the point you can't tell the difference between the wires. If you look carefully, you may see that the cotton overbraid on one wire has a black thread woven through it. This is usually the hot, but not necessarily so: testing as described by condoman is the best way to be sure.
Chances are the rubber insulation on the wire is brittle. I recommend putting heat shrink tubing over these wires before installing the fixture. Use a heat gun -- not a match or torch -- to safely shrink the tubing.
The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.