"So, we will start with the material beginning with Bragg's law. We didn't talk about diffraction on the last test. The coverage talked about generation of x-rays, but not their use in diffraction.

So, starting with x-ray diffraction up through the end of last day's lecture. And, the reason I'm doing this is that tomorrow is a holiday. There are no academic exercises tomorrow. And so, I didn't think it made a good pedagogical sense to teach you something today and have no recitation on Thursday.

You don't meet again with your recitation instructor until Tuesday and then Wednesday's the test. So, being mindful of that, I'm going to start talking about solutions today. None of that will be on the test..."