Larry, what type of yeast and how warm was the must? You are not "dead in the water" so don't panick yet!! I have had a couple batches that didn't start active(visual) fermentation for 72 hours.
Please don't freak out yet! Try to get the must warm , like 75F or so. You could give it a stir, or you could insert a tube and blow bubbles into it!! LOL, just joking, although that probably would work!
Tell us the recipe and the steps you did before you added the yeast, and what type you used. We'll do the best we can to help you get er going, you need to give us a few more details.How big of a batch? At least you got the campden in there, you'll be okay for now. Larry, if you want post the recipe you used and the steps you did before adding the yeast. You are keeping notes right?
Don't start sweating yet!! I had a batch of cranberry a few months ago that just wasn't going to go, after two weeks I was afraid of the inevitable, but the group in here was able to help me get it going.
Troy